Building with SIPs

[Rob Beckers]

People regularly ask me what the best way is to build a house that is off-grid and/or energy efficient. My answer is that I believe the use of SIPs (Structural Insulated Panels) or ICFs (Insulated Concrete Forms) is the way to go. So far I do not have any personal experience with either but that is about to change: I am in need of additional storage for business as well as personal use and decided to build a modest 1000 sq. ft. structure that uses SIPs. This thread is an account of the building process, and I will update it as things move along. Hopefully it will be informative for others that are considering SIPs for their construction.

SIP building is not new, it's been around since the 1940's and has been fairly mainstream in Europe for several decades. Yet, in North America (both the US and Canada) it is still almost unknown. Building permitting departments don't know them, nor do inspectors, causing all kinds of trouble. In fact, my contractor and I are currently still in the middle of a dispute with the Ottawa building permit department because of the use of SIPs. Hopefully this will get resolved in the near future. Most SIPs consist of two OSB (Oriented Strand Board) skins of around 1/2" thick, sandwiched around a foam core. The next picture shows a few left-over pieces that my contractor brought in from another job.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=18

For a SIP the result truly is more than the sum of its parts; The skins made of OSB are not very strong in themselves, nor is the foam core. However, when put together the foam acts much like the web in an I-beam, and it makes for a very rigid structure. Much more rigid and far stronger than an equivalent stick-frame wall in fact. Because SIPs are structural elements they can also be used to span a roof. It will take fewer trusses than with stick-framing; for my barn the roof SIPs span 8' from truss to truss (and we have very large snow loads here).

The great advantage (and reason for me to go with SIPs) is their thermal performance. A SIP wall is by its very nature impervious to water vapor and it is air-tight. Wall elements are connected using splines, with spray foam between them, the same for other joints such as roof-to-wall. This makes for a very, very tight building. SIPs do not have the cold-bridges that the 2x4's or 2x6's in stick-framing make. Wood is a pretty good heat conductor, making a 2-by stick-frame wall fall quite a bit short of the insulation value used between studs. For example, the whole wall value for a 2x4 stick-frame wall at 16" OC with fiberglass batt insulation measures at R=9.6. A SIP wall using 4 1/2" SIPs with an EPS foam core (ie. the foam core is 3 1/2" thick) measures in at R=13.9.

SIPs come in various thicknesses. The pictured ones are 8 1/4" diameter, using two OSB skins of 7/16" and an EPS foam core of 7 3/8" thickness. They have an R value of 38. The same SIPs will be used for all walls and the roof of the barn. The ones that we use are made by Thermapan (http://www.thermapan.com/), a SIP company in Ontario.

In terms of cost there is very little difference between SIP building vs. regular stick-frame building. The SIPs are more expensive than 2-by lumber, but SIP buildings go up much faster, saving in labor. My contractor claims cost is a wash between SIP vs. stick-frame. Others I've talked to either confirmed that or claimed about a 5% premium for SIP walls (ie. that's for the whole wall structure since SIPs replace the framing, insulation, sheating, and vapor barrier). So now you know why I think SIPs are the better way to build!

There is a pretty good book that discusses all aspects of SIPs. If you are considering SIPs it is definitely recommended reading: "Building with Structure Insulated Panels" by Michael Morley.

As for my barn, it'll be a single story building of 50' x 24' with a gambrel roof. There will be a second floor under the roof, and thanks to the gambrel roof shape this will add just about another 1000 sq. ft. of usable space, giving a total floor space of around 2000 sq. ft. It will be made to look like a barn and/or detached garage, to fit in with the look-and-feel of the surrounding area. We are using a shallow foundation. A regular foundation has to go down 6' in this part of the country to comply with code, a shallow foundation uses insulation instead of depth to prevent frost-heave, and only goes down about a foot. The ground floor will have a slab-on-grade, 5" of 28 MPa (=4000 psi) concrete, so it can handle my 8800 lbs forklift without cracking. In terms of construction this building will be very similar to how a regular house is constructed with SIPs, so what you see here applies for the most part directly to residential construction.

The building will be heated using an industrial (mid-efficiency) gas air heater. Besides being used for storage, I will also work in there, doing packaging/shipping and such. Hence the heating. Because it will be such a well insulated building the hope is that heating cost will be minimal.

Due to the location (with trees on the side) there won't be much opportunity to use renewable energy. Management (a.k.a. my wife) insisted on this location as the only one being suitable for a building of this size. The plan is to eventually add a PV solar awning to the front, in part as a demo-project to show solar and batteries to prospective customers. Nothing too elaborate though.

Currently the topsoil has been removed, and the foundation trenches have been dug. Some form work for the foundation walls has been put in place as well. Here it is:

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=19

Hopefully next week construction will start in earnest. We're currently waiting for the building permit to get issued. It is hinging on a few technical details that came up because of SIP use. The hope is that by Monday we'll have a permit.

That's enough typing for now. Time to have a cool one! More to follow...

-RoB-

[Paul Bailey]

Rob :What!!!! have the building inspector(s) been on vacation for the last 35 years. that they are so out of touch with SIP application.( somebody needs some retraining in the building dept. real quick to get Onboard with todays systems and differant types of insulation that are going mainstream in the market) 80 % of all timberframe homes are Sipped and have been for a Long time. Paul.... Love the project and keep us posted. (what is the heatloss estimate?, Oh forget it ,I can do it)

[Rob Beckers]

Paul, the truth is actually even more bizarre and I'm not sure I understand the full story. This particular contractor has built several SIP houses in the area before (he is in fact the only contractor I could find around here with SIP experience). According to him the previous times the plans went through permitting because they didn't know what to make of it, so they simply went with the engineer's calculations/stamps. Not too long ago the building code was changed with the intend to make it easier to use alternative construction methods, such as straw-bale and SIP. According to the contractor this is what has them on edge and looking at every detail. The point of contention that is left (we've already adjusted a number of items according to the city's wishes) is the number of trusses for the roof; we're planning on using many fewer than in usual construction because the SIPs can handle the span. Our engineer has calculated the loads, calculated the truss construction, stamped the drawings, and has talked to the city's engineer about it. Everybody seems to agree that our plans comply with every rule and regulation when it comes to roof loads, including the requirement of handling a 300% point-load at any point on the roof. Yet, somehow the city insists on doubling the number of trusses. We'll see how that pans out.

As to a heat-load calculation, no, I've not done that (yet). I'm not too familiar with it either (as an electrical engineer), so if you want to do that please be my guest! The major heat loss won't be the walls, but rather it'll be the windows and especially the very large garage door in the south-wall (15' x 9.5'). Even with that door insulated at R13 (that's probably mid-panel, not the overall value), there will be a certain amount of air leakage around the perimeter and between door panels that could well be the main cause of heat loss for the structure.

I've drawn up the initial plans using a program called Chief Architect. Very powerful software that's used by the pros. While I still was a graduate student at Duke University I bought a student's license at a greatly reduced rate. It comes in handy now. Here is a rendering of the front and side (front faces more or less south).

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=20

This is the other side of the structure with the wall cut back to look inside (that side is just a wall without windows anyway, it faces trees). The big hole in the second floor is to move goods up and down (the upstairs will be used for storage as well). The gambrel roof makes for the most usable upstairs space.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=21

The sides will be board-and-batten, stained a dark red-brown (typical barn color). The windows most likely regular PVC single-hung's with double-pane glass. I'm still looking into how to make them a little more burglar-proof, probably through the use of 3M window film (http://solutions.3m.com/wps/portal/3M/en_US/WF/3MWindowFilms/Products/ProductCatalog/?PC_7_RJH9U5230GE3E02LECFTDQG0V7_nid=HFC47QWC40beT 4DCJBL6BVgl) (makes it very hard to shatter the glass). Hopefully that'll make smash-and-grab impossible. There will be a burglar alarm as well.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=22

Work yesterday saw the completion of digging the footings, and almost all the foundation and stem-wall forms are in place now. Monday the soils engineer will come out to check the load-bearing capacity of the soil, and that will be as far as things can go before having a permit (without a permit one is not allowed to 'cover' anything, so we can dig but not pour concrete).


-RoB-

[Paul Bailey]

Hi Rob : on one of my previous posts on the group Vodka and sunshine (http://www.greenpowertalk.org/showthread.php?t=2460&highlight=vodka) Fellow Green advocate Larry Weingarten (The House on Hummingbird hill) used SIPS for the construction of his very efficient house (http://www.waterheaterrescue.com/pages/whh/pages/hummingpages/outside-systems/stress-skin-panels-part1.html)

Browse around his site to see more things that Larry has tried including the GFX, or PowerPipe that Sears is now offering, as well as some Do It Yourself Radiant walls Larry is using for heating and cooling. Paul:)

[Rob Beckers]

There's good news and bad news: The good news is that we received a building permit today, so the work can finally start in earnest. The city of Ottawa is holding firm on a detail (an expensive detail) that our structural engineer disagrees with, and we'll fight that battle later upon final inspection. The bad news is that the soils engineer was out here this afternoon and concluded that the footings that were dug are not in "undisturbed" soil. Seems we're sitting on fill, mostly sand, and he wants us to dig down another foot over the entire area. Then we'll have to truck in granular-A to fill the space, and compact that. It will certainly make for a better base (and less chance of settling), it will also add about $2K to the bill though.

I'll post pictures when things start to happen.

-RoB-

[Rob Beckers]

Today's picture is one of the Big Hole. It doesn't quite look it on the picture, but it's quite a hole. Especially when considering we were not planning to dig down much at all. In the back we actually hit the current ground water level (yeah, at 2 feet below grade, we live in a swamp here). The soil engineer came back and wants us to dig a few areas down even more due to the presence of organic material, those are the dark patches in the picture (it decays, and then the soil settles, not good for foundations). That digging will be done by hand. Right through this hole is the natural gas line that feeds the house. It runs where the 'hump' is in the picture, you can see some of the line on the right side. This is before the pressure regulator, ie. a high pressure line. The guys had to be very careful not to hit that line, or things would have gotten ugly in a hurry.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=23

Tomorrow we'll undo all that hard work and fill the hole up with granular-A, a mix of various sizes crushed stone and stone dust. When compacted it makes for a very firm base. Then it's back to form work and foundation concrete.

-RoB-

[Rob Beckers]

The granular-A (or "GA" as it's called in the trade) came. Six dump trucks full of it. Since the contractor had just two people shoveling between truck loads, I was put to work spreading the loads with the little Kubota tractor I have (with a 4' front loader and a 1' backhoe). During the weekend we had torrential downpours, turning the construction hole into an outdoor pool. Monday the contractor rented a large vibrating plate compactor to compact the GA (it's a type of engineered fill that compacts very well, and sets almost like concrete when compacted). They almost lost that compactor: In the back half of the hole the combination of water and soil liquefied when vibrated, eating up the stone, and forming a sink-hole that started to swallow the compactor. That was the end of that.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=24

With hindsight being perfect; what should have been done was to put down landscape fabric (geotex), before putting in the GA. That would have prevented the stone from mixing into the soil, and it would have compacted fine even with all the water present. With the water table being what it is here, it's going to take a long time before things dry out enough to proceed (I'd guess a minimum of 2 weeks). Unlike clear stone, GA must be compacted before building on it, otherwise it will settle many inches over time. I spent an hour or so this afternoon to level the GA a bit better using my tractor, and filling up the holes. The theory being that by displacing the water with stone it will dry up a bit faster. With all the fines (stone dust) in GA it will also draw up the water faster, for evaporation. The next picture is what it looks like now. It looks dry now, but dig an inch in the back half and you hit water.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=25

The SIP panels for this build arrived yesterday, as did the floor joists (though they are more like floor trusses than joists). The joists are engineered to span 24 feet without support, that is why they are so large. I don't want any columns inside the structure, they get in the way when driving a forklift around.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=26

What is next, is to fill the remainder of the needed height with clear stone ("gravel"). The concrete slab needs at least 4" underneath it, as a capillary break so the slab won't wick up the ever present moisture (We are basically building in a swamp here). That will have to wait until the GA has dried enough so it can be compacted.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=27

Somehow I'm feeling we're taking one step forward and two steps back these days...

-RoB-

[Rob Beckers]

We've been back for a week now from our vacation (drive across Canada) and the contractor has been back to work with a vengeance during that week. Work is progressing rapidly. I've been busy catching up on my backlog of work, hence the somewhat belated post.

It never really dried up in the foundation hole, during our absence it had been raining almost daily. The granular-A fill has been compacted though: The contractor placed a number of 2x8's over the surface and ran the compactor over the top of those. On top of the GA we put 1" clear stone, using a stone-slinger, to get the foundation at the proper height. Clear stone will also be used under the concrete slab (at least 4" of clear stone); this forms a capillary break so water doesn't wick up from the ground into the slab. Granular-A has fines in it (stone dust) and it would wick water up if the slab was placed on top of that. The foundation wall forms have been placed back, and the foundation poured. In fact the forms have already been removed and the contractor is currently stacking wall elements (SIPs) on top. Things move fast.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=28

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=29

Those panels in the middle are actually the roof panels. The contractor is using them to get a smooth work area for lifting wall panels up on the foundation wall. The sill plate is a pressure treated 2x8, put in place with PU-foam under it.

one aspect of SIP construction I would like to show is how panels go together, using splines. Normally panels are connected with foam splines; they are basically the same construction as a SIP (OSB-foam-OSB), just a bit less wide so they fit in the groove of the SIP. A bead of PU-foam is put around the inside perimeter of the groove before inserting the spline, to make the connection air-tight. The spline is then nailed in place on both sides through the OSB. The advantage is that there's foam between the inside and outside, preventing cold bridges. Those 2x6 or 2x4 sticks used in conventional framing are actually pretty good heat conductors compared to insulation materials such as fiberglass or rockwool (or EPS foam as used in SIPs). These splines avoid that.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=30

Not all splines are made using foam, some have a double 2x8. This is normally not needed, since structurally those SIPs are much stronger than stick frame walls. At every point that has a roof truss over it we have a solid wood spline, made from 2x8's. Again, the spline is put in place with a bead of PU-foam, to make the connection air-tight.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=31

The first panels were placed last Friday. Notice how foam is used to seal all connections. Those panels are 12' high, a whole lot higher than it looks in the picture!

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=32

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=33

Today the contractor is just finishing up placing all the other panels for the ground floor. With SIPs walls go up really, really fast. I'll try to snap some pictures this evening to show where things are at.

-RoB-

[Rob Beckers]

What a difference a day makes: All the ground floor walls are up! Keep in mind, with SIPs it's not just the walls, but also the insulation and vapor barrier. The contractor has started mounting the joist hangers for the upstairs floor, so those joists will probably go in tomorrow. This is what it looks like right now:

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=34

The amount of inside space is a bit more than I expected (a good thing!). Though in terms of surface area this is about the same size as our existing garage, it feels much larger. Probably also due to the 12' walls.

A note to anyone that's going to use SIPs: Make sure that they are stored before use so there is no ground contact! Several panels have severely swelled/dirty OSB where they were in touch with the grass and soil (that's how they were dropped off). Unfortunately those were 'inside' faces (A SIP has an inside and outside face, where the outside OSB has a coating to make it more waterproof so the building can be left uncovered during construction for a longer time). In my case the inside face is also the finished inside wall; I plan to paint them white but that's it, there's no drywall going over it. The contractor has reversed those panels, and put the outside face on the inside. That works, but is not a great solution, because the OSB of the outside face is much slicker/smoother than the inside faces, and I have a feeling that will be very visible after painting.

I've been busy this afternoon moving away excess soil. As you can see on some of the pictures we have a hill of soil on the left side of the building. Most of that won't be needed, just a little goes towards backfilling after the insulation goes into the ground for the shallow foundation. So I'm using a small Kubota tractor with a 4' front loader to deploy the soil for landscaping. That is turning out to be quite a bit of work, as the bucket is pretty small. Slowly but surely I'll get there...

-RoB-

[Rob Beckers]

Just a few days later, and work is well under way for the second floor (attic). All the floor joists have been placed, and some of the sheathing has been glued/screwed down. Hopefully in a few days work will move on to the roof.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=35

While inspecting the work, I noticed that the solid wood splines between some of the panels are not holding up as they shoot. The two 2x8's that form the spline are pulling apart just enough to break the foam seal, forming places for air to leak through. I'll have the contractor foam both sides of the joint on Monday, to fix that. Other than that, things are looking good!

-RoB-

[Ralph Day]

Rob,
Make sure he uses some robust deck screws to stabilize. If shrinkage or drying has caused problems already, don't just rely on foam to hold...stabilize with some screws (if this makes any sense). Sight unseen i'd guess that the 2x8's might have twisted or shrunk wheras the chipboard has not, or done so at a different rate.

Ralph

[Rob Beckers]

Last week saw the completion of the attic floor, and the beginning of roof construction. For the floor we're using a product called "Advantech". It is oriented strand board (OSB) on steroids; stronger, less flexing, much smoother, more weather resistant, and a harder surface. Since this will be the finished floor for the upstairs, the small additional expense seemed worth it. The current thought is to do a light sanding (after the whole building is finished) and put a few coats of polyurethane on it. That should look quite sharp, and make for a durable floor.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=36

Upstairs the guys have been using the newly built decking to construct the roof trusses. These were designed by an engineer and consist of double 2x10's with 1" plywood gusset plates on both sides at all corners. They are very big, and very heavy! There are only 6 trusses, on 8 foot centers. This was one of the points of contention with the city; because SIPs are structural elements they can span quite a distance under load (for the roof that's snow loads in our climate).

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=37

That's the outside. Here's the inside.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=38

I have also been window-shopping last week and ordered the windows for the barn. The company I went with is Thermotech (http://www.thermotechwindows.com/), located right here in Ottawa. While they also make their own line of high-end fiberglass windows, the ones that I ordered are of the North Star brand (http://www.northstarwindows.com/), vinyl single-hung windows. They look to be very well made, have decent insulating properties (double-pane, low-E, and argon filled), and come with a life-time warranty. In terms of price they are similar to the other brands.

The reason we went to Thermotech (http://www.thermotechwindows.com/)was actually to look for new windows for the house. Our 20-year old aluminum-clad wood windows are pretty well gone, and have huge air leaks around their frames. When you look into energy efficient buildings (on- and off-grid) the Thermotech name often comes up. Their triple-pane, krypton filled fiberglass windows are about as energy efficient as one can get. Life-time warranty on those too, so definitely something you may want to look into if you need windows with low(er) energy loss.

Ralph, the problem with those wood splines is indeed moisture related. We've had torrential downpours here almost every day for the past two months. I suspect that the splines are cupping between the panels; the panel side is dry because the SIP keeps it that way, while other side is exposed and wet. We've foamed in the space between the SIPs on the outside, so it's air tight again, and now that there's decking on top it should be drying out. Structurally it makes no difference, these splines are loaded vertically. We do want to keep the building as tight as we can though. I will likely caulk the inside seems where those splines are with paintable caulk just before painting, just to make sure.

-RoB-

[Rob Beckers]

Just a day of work, and a good part of the roof panels have been installed. That's the SIP advantage; it's fast. All the roof work is done by just two guys, and no crane, they're simply lifting the panels in place. They go down with very long screws into the top plate and trusses.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=39

Just like the wall panels, the roof panels are put together using foam splines and spray foam. The plan is to foam a wedge-shaped piece of SIP into the cold-bridge that now exists where the roof meets the attic floor.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=40

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=41

I'll be visiting a roofing shop today to look into standing-seam metal roofing for the barn. The usual 25-year warranty shingles only last around 15 years in our climate, while metal is good for 50+ years. In the end it also depends on price of course. If anyone has suggestions about metal roofing please let me know, right now I don't know a thing about 'm.

-RoB-

[Ralph Day]

Hi Rob
The factors that age shingles in this climate also work on steel, albeit at a slower rate. My first house roof lasted about 5 years before i replaced it with steel. THe roof is low sloped so lots of solar aging. The steel is structurally sound, however after 15 years i decided to paint it, and then every 5 years after that. It's not indestructible, and you don't want to scratch it. Anywhere there was a scratch or a trim cut, it rusted.

The screws, although painted, also rusted after years of exposure. Just plan on painting eventually. I've seen barn painters do roofs like you are constructing, quite easily.

What's the orientation of the long run of the roof? Good solar exposure for PV panels? If so, i've read about clips for mounting structures (pv panels) to the standing seam roofing. The users were in Florida and the systems have stood up to repeated hurricane exposure...what better recommendation could there be?

Looks like quite a wharehouse, where is the office?

Ralph

[Rob Beckers]

The office is in the attic of course, there's spot in the front with a great view! :) The computer renderings I posted earlier in this thread give an idea of that front with the windows. It won't be my full-time office, but I do plan to put a desk so I can spend some quality time there.

Alas, the main axis is south-west to north-east (and closer to north than east). With trees on one side there is almost no opportunity for PV or anything else solar. I looked long and hard at placing the building in another spot, where there would have been a south facing roof. Ultimately that was voted down by Management (a.k.a. my wife) for a location that is less conspicuous, hidden from the nearest road by trees. The only place for PV would be the front face, where the garage door is. That is about 30 degrees off south and has a clear view. The hope is to construct a PV awning there at some point. More as a demonstration of PV than to actually produce serious power. I have to make do with what I have got.

Thanks for the roof info. My understanding is that when it comes to metal roofs things have improved very rapidly in the last few years, with coatings that really handle a beating (and have a long life). I'm off to the roof shop in a few minutes, we'll see what they have to say.

-RoB-

[Paul Bailey]

A nice little solar chart shows you can be way off south and receive 80-90% of your isolation. ( Rob -I know you already know this but others may not!!) Paul:)

[Rob Beckers]

That's a very nice chart! Hadn't seen it presented in that format before. Where did you find this Paul? Looks like the chart was made for locations 35 degrees north. It would be nice to have one for 45 degrees north (where we are).

Solar potential of the new barn is poor: The only 'open' side of the roof that's not facing trees is on the north-west. Roof slopes are 60 degrees for the top part, and 30 degrees for the lower sections. Putting PV up there would be like throwing pearls to the pigs. A nice little solar awning is a possibility though.

Meanwhile, the guys finished most of the roof last week. The only remaining sections are the very front and back, where they have to build a gable wall before the roof goes on. Back gable is almost done, so by the end of the coming week it'll be completely roofed in (excluding the roofing itself, we will still need to nail something on top of those SIPs).

-RoB-

[Rob Beckers]

The roof is almost complete now, with just a little bit at the front to do. The gable wall there is still being built, and the roof panels go on as this progresses. So far the entire construction job was done without any use of crane or other mechanized means of lifting SIP panels, they were all put in place by hand.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=42

Panels are foamed in place to seal them to adjacent panels, and special (foot long) screws are used to screw them into the top plate as well as the roof trusses. This is not going anywhere!

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=43

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=44

Work has also started on the shallow foundation insulation. Both the foundation walls and the soil get insulated with 4 inches of polystyrene foam sheets, extending 4 feet out from the walls.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=45

My job is to dig out a 4 feet shallow trench for those sheets, but first I have to give the gas company a call and have them mark their line. There is a high-pressure gas line running right under the building. We have managed to miss it so far, and it would be good to continue that way.

-RoB-

[Paul Bailey]

Hi Rob I almost forgot about the Chart. It is from Viessmann. I'm Looking for an Ajustable format of this, but no luck as yet. Yes its 10 degrees out from us but it gives us the general idea as to how far off true south we can be and still reach high efficiencies ,Minus 10-30% (especially hot water heating):)

[Rob Beckers]

I've turned all the pictures into an 'album', one of the new features of the forum. That means the pictures can also be viewed by themselves (http://www.greenpowertalk.org/album.php?u=1). Members can create one or more albums, and share them either with friends/groups only or everyone.

Meanwhile, work on the barn has progressed with a vengeance. The roof is now complete, both gable walls have been built, and all the window/door openings have been cut. I need to snap a few pictures over the weekend so that I can show where it's at.

-RoB-

[Rob Beckers]

All the SIP work is done now; the walls and roof are complete and the window/door openings have been cut. For most of the window openings there is no need to do any framing around them (as is normal for stick framing), it is simply a matter of taking the saw and cutting a hole. A hot-knife is then used to remove some foam from the perimeter of the window opening, and 2x8 lumber is put in there to have something to nail to when the window gets installed. In the case of my barn there was one window opening that cut through a solid wood spline (the double 2x8's that transfer the roof truss load to the foundation). For that opening a bit more work had to be done: The SIP panel was cut to the ground at that opening, and double 2x8 splines were inserted from the window corners down to the foundation wall.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=46

I'm meeting the roofer this morning to go over that part of the job. The plan is to use metal roofing panels that look like shingles, made by Decra (http://www.decra.com/shingle.htm). These have a 50-year warranty. They are not cheap, the total of materials and labour is almost twice the price of shingles, but with shingles lasting only about 15 years around here it is a matter of pay now or pay later when it is time to re-shingle.

Meanwhile I've been spending all of yesterday, and will spend most of today, digging trenches with a small Kubota backhoe. These are for electrical, data, and natural gas. The size of the stones that are coming out of the ground is unbelievable! Slow going...

-RoB-

[Joe Blake]

Solar potential of the new barn is poor: The only 'open' side of the roof that's not facing trees is on the north-west. Roof slopes are 60 degrees for the top part, and 30 degrees for the lower sections. Putting PV up there would be like throwing pearls to the pigs. A nice little solar awning is a possibility though.

-RoB-

Rob,

Just thinking about your garage door. What sort of door have you/will install? I was wondering whether a flat tilt-up door would make a solid base to mount some small flexible solar panels. (Roughly A4 size similar to what I'm using to charge my electric trike.)

http://i82.photobucket.com/albums/j245/saxeharp/Boys5Dec06031.jpg

Each panel is nominally 2.6 watts. You could probably even arrange to have them at a smallish angle to the sun, and still not interfere with overhead clearance when the door tilts up.

Not quite sure how air-tight a tilt-up door is though. If you're thinking of an awning, why not build a little "airlock" with the panels on the door and roof, and have an air-tight inner door?

Or alternatively, have the roof of the air lock transparent to act as a light well to make up for the closed tilt up door?

Joe

[Rob Beckers]

The gas guys are coming out tomorrow to look at installing a natural gas line from the barn to the house. The plan is to hook up a heater in the shop, to keep the contents from freezing in the winter, and to be able to work there in reasonable comfort. The building is very well insulated, in fact, the weak spot is probably going to be the garage door. Not knowing much about heating, nor having done any heat-loss calculation I estimate that something around 40,000 to 60,000 BTU should do the job.

Does anyone have a recommendation for a heater brand/type? I've been looking at a Lennox LF24, or a Schwank STR-JZ (though I can't find any efficiency info on that one). What I need is something that's quiet, direct-vent (both combustion air and exhaust hook up to the outside), and mid-efficiency (80% and up). A reasonable price is a plus too of course.

The past weekend I've been digging a very large ditch using a very small Kubota backhoe. Below is a picture, though that doesn't quite do justice to the size of the dig. It was, quite literally, a pain to do; the machine wasn't really meant for the size of the stones that came out of the ground. Looks like I'm sitting on a gravel pit! Code requires that gas lines are at least 20" below grade, while there also needs to be separation between the electrical and gas lines, so most of the ditch is 3 feet wide. That will also help to keep the data lines (phone and internet) away from the power line.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=48

-RoB-

[Rob Beckers]

Rob,

Just thinking about your garage door. What sort of door have you/will install? I was wondering whether a flat tilt-up door would make a solid base to mount some small flexible solar panels. (Roughly A4 size similar to what I'm using to charge my electric trike.)

<<SNIP>>

Joe

Hi Joe,

The door is slated to be a regular multi-panel folding garage door. Same type as is popular for residential use, though it'll probably a little bit beefier due to the size. They are insulated, and I'll be looking for one with the best insulation I can find/afford. Seal around the door should be reasonable. Not quite as good as, say, a window, but they have come some way in the past few years in proper weather stripping. It'll be a solid door (maybe a few little windows at the top), mainly because of theft concerns. It's better not to put what's in there on display. Using an inner and outer door is a bit more complicated than I'd like to make this. As mentioned, I expect the door to be the weak link in terms of heat-loss of the building, not much that can be done about that (at least not easily/cheaply).

To get decent production from PV in these parts the panels need to be at an angle of around 45 degrees. So, a solar awning would make sense. Still, with the trees around, and being off-south by about 30 degrees I do not have high expectations there. It'll be more of a demo project for prospective customers.

-RoB-

[Rob Beckers]

The past two weeks have seen quite a bit of work, the guys were out almost every day. The biggest visual difference is that much of the board and batten siding has been installed. Because the windows have not arrived yet, the batten around the windows have been skipped. They'll go in after the windows have been installed and trimmed out. The windows are due early September.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=50

The Big Trench has finally seen some use: Today the gas guys put in a 1" gas line, going from the meter to the side of the barn (the yellow plastic pipe). Code here says that the line has to come above ground before going into a building. So there's a steel riser next to the door. We'll drill through the wall just above that and run the rest of the line inside, to the heater.

Besides gas, there are two runs of 1 1/2" conduit in there as well. One is for electrical; there's a 100 Ampere panel inside the barn. The other is for data and phone. To keep interference down I've separated them by at least a foot, more in most places.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=51

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=52

Inside, the electrician is almost finished running outlets and hooking up light fixtures. For the downstairs we have 20A outlets, so it's a little easier to hook up equipment without tripping the breaker. All the downstairs outlets are also on a GFCI, making this much safer for a small extra investment in my opinion. Strangely, Ontario electrical code does not require ground-fault interrupters. From my stay in the US I know it's mandatory over there for a concrete floor.

Hopefully next week will see the floor being poured. Meanwhile, I have the weekend to backfill the Big Trench. The work never ends!

-RoB-

[Rob Beckers]

Yesterday evening was spent 'googling' heater choices. It looks like the Lennox LF24 won't work for me, it is not a direct-vent heater (drawing combustion air from outside, and venting outside). In fact, there don't seem to be many choices when it comes to garage-type heaters, or "unit heaters" as these things are called. The most promising option right now looks to be the Sterling SF series (http://www.sterlinghvac.com/html/modelsf.htm). If anyone has any experience with these (or with the Sterling brand in general) I would very much like to hear about it.

Suggestions for other brands/types of heaters are welcome too!

-RoB-

[Paul Bailey]

Heat Loss Rob and I have spoke off the main forums a couple times Re : the building heat loss (advantages of SIP's and air infiltration losses kept to a minimum) Attached Pic of the first rough draft and some general numbers on heating dollars ( these will vary widely based on your area and energy market prices of the day) Since Rob has not yet decided on the heating source/and how much, and how hot he will keep the building He will save ALOT of money off the numbers shown. I also need to tweak some dimensions ...but were close. More to follow ...Paul:) Oh ! for those interested the loss calculates to 23,000 Btu on this first draft, Rob has also added more perimeter insulation at the footings and remember that the footprint is in the 1150 Sq. Ft. range but the gambrel barn style roof is allowing him double that for working space on that same footprint. Having R-35 walls sealed tight around this stuctural envelope is a huge Bonus as well....

[Rob Beckers]

Thank you Paul! This is very much appreciated.
What does the 23,000 BTU number mean? That a heater of that effective heat output would suffice to keep the building at a toasty temperature?

The weak link in this building is the garage door. Not just because the door itself is at best R13, and it won't seal as well as a wall. There is a cold bridge where the slab passes under the door. Concrete is a good heat conductor, so quite a bit of heat will get conducted out of the building through there.

-RoB-

[Paul Bailey]

Rob : I have adjusted your numbers up to a heat loss of 26,000 Btu at a 100 degree delta. ( from 70 deg F (21 C) to -30 F (-34C) ). I had not added the main garage door of 15X9.5 feet at the time of the previous Picture/chart.These numbers may still vary based on site specific influence such as Wind,Solar gain,snowfall,Heating Degree Day count for a given winter and so on, So theres' alot of variables. As you can see a few Small yet important factors or adjustments to the building R-value in differant spots can really affect the yearly total and the $$$$ alot , especially these days. I guess thats why I tend to gossip so much about Foam insulation, and Radiant heat so much since it delivers the heat and has efficiencies in doing so that are way ahead of most other systems . Paul:)

[Rob Beckers]

Paul, how does the 26,000 number translate to heater size? Or is this the required heater size (plus some extra to account for unaccounted heat losses)?

-RoB-

[Rob Beckers]

Yesterday was concrete day: The floor was poured.
For this particular floor I had calculated that we needed at least a 5" slab (using my 8700 lbs fork lift as the maximum load that it needs to carry), and at least 28 MPa (= 4000 psi) concrete. The city required us to use even stronger concrete: 32 MPa (= 4600 psi) with 5 - 8% air entrained. This is the stuff they use for sidewalks, the air helps keeping it together through freeze - thaw cycles. If you can find it, the American Concrete Institute guide no. 302.1R-96 "Guide for Concrete Floor and Slab Construction" (http://books.google.com/books?hl=en&id=HdL2h0vBMUkC&dq=%22guide+for+concrete+floor+and+slab%22&printsec=frontcover&source=web&ots=JHkIv8zfrM&sig=LWEdd5jvsqxQlqxwiwKosC9yIbM&sa=X&oi=book_result&resnum=1&ct=result#PPA1,M1) has good guidelines on proper slab construction, while the Portland Cement Association publishes "Slab Thickness Design for Industrial Concrete Floors" (http://www.cement.org/bookstore/profile.asp?itemid=IS195), which goes over the thickness and strength calculations.

To prepare for the pour, a truckload of 1/2" clear stone was brought in with a stone slinger truck. This was graded (more or less), and covered with polypropylene (plastic sheet), then 6" wire mesh was placed on top. The clear stone serves as a moisture break, by not allowing water to wick up into the slab. That is something I know all too well from my basement floor, which is perpetually damp. The polypropylene serves two purposes; it keeps water vapor out of the slab, and it keeps the wet concrete from oozing into the clear stone (which would negate the effect of the moisture break). The plastic is pretty thin, and during work it gets a few holes here and there. That's OK. This is more of a "big picture" thing. Contrary to popular belief, the wire mesh is not there to keep the concrete together, nor to make it stronger. Concrete in a slab only gets used in compression. Putting steel in concrete makes it stronger in tension, it does zip for compression. What the mesh does is keep the pieces of concrete together, at the same height and in close proximity, when the inevitable cracks develop in the slab. During the pour the mesh is pulled up by the workers so it sits (hopefully) at about halfway to one-third of the slab.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=53

The concrete crew brought a laser level along, so they could get the slab at the proper elevation and with the proper slope. At least that was the hope. It didn't quite work out that way, but more about that later.

I had previously talked to the contractor about the need to isolate the slab from the surrounding foundation walls. Normally bond-break or joint-filler material is used for isolation joints (sort of really thick paper soaked in brown or black stuff), and from his reply at the time my understanding was that he understood what we were talking about. Not so. When I asked the contractor on the morning of the pour if he had brought joint-filler along the answer was that he was going to wrap the plastic sheeting up the foundation walls, and that would act as a bond-break. The only problem with that is, it doesn't. The foundation wall is not smooth, especially this particular foundation. The concrete slab simply 'keys' into all the holes and protrusions of the wall, bonding it in place. Also, there's no room for thermal expansion/contraction. It simply isn't a bond-break. Running the plastic sheet up the wall is not a bad idea by itself; it keeps the concrete off the walls and it can later be cut at the slab so it's invisible. It's just not a bond-break. With concrete trucks on the way, and a crew waiting, what can I do. It was too late to get the proper stuff. It's the small details that make for construction that lasts semi-forever vs. just the 5 - 20 years people seem to expect in this part of the world. My contractor is probably one of the better ones, still, he too doesn't seem to be aware of those 'best practice' details (or simply ignores them to save time and money).

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=54

The guys proceeded the pour, shooting elevations, screeting, and troweling. They had a powered screet that could do almost half the floor width at the same time! Now, the calculation for this floor was that we would need just over 13 cubic meters of concrete, so 14 cu. meters were ordered (that's two trucks). Halfway through it became clear that this wasn't going to be nearly enough, and we ended up using around 17 cu. meters (guess who's paying). The gravel under the floor wasn't quite at the right level, and keeping 5" at the highest places meant having 7" or 8" in other places. It makes for a stronger floor, but concrete is not cheap!

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=55

I had never seen how a slab was made, and the finishing process was interesting. After letting it sit for around 3 hours (so it's just wet enough that walking on it leaves 1/2" footprints) the guys got back to work with a power trowel. This looks a bit like a fan, put on its head with the blades sitting on the concrete. Running this over the concrete mashes up the top layer; pushing down the aggregate (stone) and bringing up the more liquid stuff. It also knocks down the weaker top layer. It leaves a pretty rough surface, so another guy follows behind with a hand trowel, to make it completely smooth. They run that same power trowel another two times, after another 2 hours or so when the top is hard. In the end this leaves a mirror smooth and hard surface.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=56

The last act of concrete slab construction is to cut the joints. These are not "expansion joints" as they are often called, but controlled cracks. Most slabs will crack if left to dry. This usually happens in the first day of drying and the cracks could go anywhere. Pretty ugly! To make the slab crack in predetermined places a diamond saw is used to cut about 1/3 into the concrete (in our case about 2"). This was done after letting the concrete set for about 6 hours. The same publications mentioned above also let one calculate what the maximum distance should be between saw cuts, in our case that worked out to 12 feet. Smaller is OK too, but too small will make the concrete 'float', in that heavy objects tilt up the pieces. We stuck with one cut down the middle (the floor is 24 feet wide, so that makes 12 feet), and then every 12 feet from the front wall (it's 48 1/2 feet from wall to wall), 3 more cuts in all.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=57

In case you're wondering about the puddles in that last picture: I got a hose out this morning to see if they sloped the slab properly. Besides that, it's a good idea to water down the concrete so it dehydrates less (less cracking that way). The idea was that we would have a shallow slope downhill from back to front, and the sides to the middle, with a more pronounced slope in the front area where snowy vehicles get parked (snow melts, lots of salty water, big mess in winter). Well, that was the idea. They didn't quite get it right. There is a shallow back to front slope, but water puddles on the sides in the back. Not a whole lot, maybe 1/8" so that's OK. What they didn't get right is the front area where there should be more slope and draining down the middle. Somehow the middle of the doorway (the big garage door) ended up as the high point. The water, reluctantly, drains from the sides of the door frame, with pretty significant puddling about 10 feet in on the sides. My complaints to the contractor fell on deaf ears; the puddles are about 1/4" - 1/2" deep and it seems that's 'within tolerance'. :mad:

If the concrete guys had gotten the grading right there would have been much more slope in the front area, and a few small mistakes would still have kept the floor draining outside. But what can one do, after the concrete sets its basically all over... I did read up a bit on how concrete slabs are made, 'best practices' if you will. The better way to do this, it seems, is to take a few hours before the pour and stick some rebar into the ground at regular spacings (say every 7 feet). Then pound the rebar down to the correct elevation, mark it with fluorescent spray paint (so people don't trip over them), and use them to screet of off. Once the concrete has been screeted they can be simply pounded down an inch or so, to make them disappear into the floor. Sounds much more foolproof to me than trying to get the elevation right while guys are running around with wheel barrels full of concrete, guys screeting and throweling, and generally everyone in a hurry to keep the concrete flowing. Live and learn.

-RoB-

[Ralph Day]

Hi Rob
Yes concrete is expensive...and very heavy! On my garage floor pour i didn't know about grade stakes (your re-bar sections for depth reference), so on a 20 foot wide floor it was hard to see a "pile"of concrete in the middle area until you proceeded to screed it. A fast attack with shovel and rake fixed that but boy, what a workout! Imagine shoveling sand and gravel, then throw a gallon bag of water onto it...presto, that's concrete! Heavy stuff.

The building looks great, but drainage on any concrete surface is a bugger to get right. Might i suggest a big floor squeege be kept in the parking area? A quick swish of slushy slop or standing water could be accomplished with it. Princess Auto or someplace similar will have large floor squeeges...maybe a commercial cleaning supplier.

Long absence in August due to holidays and computer vacationing at Future Shop (third time in 2 years). Toshiba...bahh!:mad:

Ralph

[Paul Bailey]

how does the 26,000 number translate to heater size? Or is this the required heater size (plus some extra to account for unaccounted heat losses)?

-RoB- Hi Rob : re: the heater size: The 26,000 is the Design heat loss at -30 (30 degrees below zero Degrees) , so in answer to your question about Heater size I would probable look at at least a 40,000 BTU unit if you are looking at a quicker recovery time on a cold day and the main garage door has been open and its nice to have the faster recovery for Catch up anyway. In housing applications there learning now that Efficiency is now in the Big picture of things, and they realize that the heating equipment is/ and has been way oversized (sometimes 3 to 4 times) and the short cycling drastically effects overall actuall Effic.Vs nameplate rating which is not good:(

[Rob Beckers]

The barn is designed to have a frost protected shallow foundation (FPSF in short). Now there's a mouth full, try that the next time you're at a BBQ party! :p What this means is that instead of digging down 6 feet to build the foundation wall (the required depth in our climate), it just needs to be a mere 12 inches below the surface. The foundation is protected from frost heaving by putting in insulation against the outside wall surface (ie. vertical), as well as horizontal insulation that extends outward from the building. The heat from both the ground and the building (if it is heated) combine to raise the frost depth to above the foundation level. What is more, the horizontal insulation performs the same function as insulation added underneath the slab. Simulations by people that know this far better than I do show that 4 feet of, say, R20 on the outside is virtually identical to 4 feet of perimeter insulation of R20 on the inside under the slab (Slabs are normally not insulated over their entire surface, unless there's in-floor heating, only the perimeter is insulated).

There are some good resources on calculating a FPSF for a particular climate. The National Association of Home Builders (www.toolbase.org/PDF/FieldEvaluations/NAHB_fpsf.pdf) is one, the US Department of Housing (www.toolbase.org/PDF/DesignGuides/revisedFPSFguide.pdf) has another. In the case of my barn, we're putting in 4 feet wide XPS foam sheets of R20 total (two sheets of 2" thickness, each is R10). That is about double of what is needed according to the calculations, the city made us do this. It is not a bad thing, as it in essence also increases the slab insulation and it is welcome there.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=58

My contractor had already made attempts to stick the stuff into the ground. Unfortunately his idea was to put it essentially at ground (grade) level. Not only does this violate the design guides for FPSF, it also makes the foam sheets very vulnerable for cracking, moving, and other damage. His response to that was "it cracks anyway, a few cracks/gaps is not important". I disagreed. Since he already had his guys dig a very shallow trench, basically to level the ground, he was not going to spend more time digging and that became my responsibility. You gotta love these contractors. So I spent the past two days digging; some with a small Kubota tractor that I own (it has a 12" backhoe), some by hand. It was hot and very sweaty! :( The next picture shows the shallow trench. It slopes away from the building, another requirement any time you have more than 2 feet of insulation, to keep water away from the building. I'm putting drainage tile (corrugated plastic tube with holes in it and a sock around it) around the building, in case water gets close. The sheets of insulation go on top of that.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=59

That's where the FPSF is at right now. Tomorrow I'll put the sheets of XPS in the ground (and re-install the ones that were vertically on the foundation wall). The contractor was planning to just dump the sheets onto the ground. I'm thinking that it might be a good idea to get a few cans of low-expanding poly foam (it's a glue for XPS), to keep the whole thing together while it gets backfilled. I'm not too worried about a few cracks and such and their effect on the total insulation value, but why not do it right the first time?

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=60

The guys also build a staircase last Friday. They did a good job with that one! The stairs are solid. A minor point is that they used some scrap rough lumber (the fuzzy stuff, in this case with mud and stain on it) to act as spacers here and there. This wouldn't be a problem for framing, where a multitude of sins get covered by drywall. In my case that wood is the 'finished' surface. A concept that I am having a very hard time conveying to both the contractor and subs, such as the electrician. I'll take the wood pieces out later and replace them with something better looking. At least it's much easier now to get upstairs.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=64

Talking about the upstairs; at this time there is a cold-bridge (and large air leak) where the roof meets the upstairs floor. The foam wedges in the picture will go into that gap, using spray foam to seal it all up. Just like the one on the left side (it's not foamed in, just sitting there loosely). It is left open for now to allow for the building inspector to do his job.

Well, we're in the home stretch! The windows are coming this week. Electrical should be done too, and hopefully have final inspection by week's end. What is not looking good right now is the roof. The metal sheets for it are backordered and not coming in until the end of September. I will probably have the roofer put underlayment on, stuff called "Resistor Plus", to water proof the roof for the time being, so I can get started on putting some paint on the walls.

-RoB-

[Rob Beckers]

My back is still hurting, but we have most of the foundation insulation into the ground now. As mentioned before, it extends out just over 4 feet from the building, and is R20 in total insulation value. This is what keeps the slab warm, and the foundation wall from heaving.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=65

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=66

The back-breaking part was to backfill the entire trench by hand. I didn't want to drive machinery on there, at least not until most of the soil was back in place to keep the foam panels from going to bits. Right now 3 of the 4 sides of the building are done, I still need to dig and install insulation in the front. That will have to wait until next week though; the roofer wants to come this weekend to waterproof the roof. The actual metal roofing material is back ordered until the end of September. I don't want to wait that long for a leak-proof roof, so the roofer is going to put an underlayment on called 'Resistor Plus', basically a synthetic version of builders felt that holds up much better when exposed.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=67

As you can see from the last picture, the windows have been installed as well. So, things are coming together slowly but surely. Electrical is supposed to get finalized on Monday. Then there are a few odds and ends left to do (such as a garage door!).

-RoB-

[Steve White]

hi,

I just read the thread and was wondering what your cost psf for the structure was minus the windows and doors?

[Rob Beckers]

Hi Steve,

It works out to around $51 per square foot (adding the few windows and doors doesn't make much of a difference). People I've talked to, who did more 'regular' residential SIP construction of their house as opposed to a 'barn', mentioned their calculations showed an increase of 0 ... 5% in price between stick frame vs. SIP.

I have not posted much lately, mainly because there's not much change to show on the building. Things have been moving along on the details; the contractor's part of the job is finished and now it is my turn to finish things inside. I have been installing the unit heater (it's hanging on the ceiling now), and will likely spend the afternoon on the vent/draw pipes for it. The gas fitter is coming later this week to hook it up to the gas line we put in the ground to the building.

-RoB-

[Rob Beckers]

The past few weeks I have been working away on the small stuff that still needed to be done on the barn. Even so, there's enough left to keep me busy for a while. Here is an update.

I have installed the heater last week. As mentioned before, it's a Sterling mid-efficiency (81%) natural gas unit heater, 60,000 Btu/hour. Small for the size of the building, but with the insulation in there it should be sufficient. The unit is direct-vent, so it draws its combustion air from the outside.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=82

There's probably some trick to this, but I had a heck of a time to make the vent pipe 'lock' (it comes as a sheet, you bent it round until the edge clicks into a slot on the other edge). Anyway, it's up, and it's working. The gas guy hooked up the gas line last Sunday. The unit comes with a special vent kit, using a single 6" hole in the wall. The outside is shown on the next picture. In case you notice the vent pipes are not running level; they are supposed to slope towards the outside a bit. So condensation can run out.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=83

Today I have been digging out the front side of the building. The insulation still needs to go into the ground there, and I have to put down some GA (and tamp it with a plate compactor) to serve as a drive way until we redo the asphalt driveway to the house.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=81

As luck (or lack thereof) would have it, I managed to hit an electrical line that runs from the house to the two lights at the beginning of the driveway. :evil: Electrical lines are supposed to run at least 20" underground by code, I'm digging barely 12" deep. Some bad words were said. I'll have to get a splice kit tomorrow and some UF cable, fix the thing again.

It is a race against the clock now, with winter just around the corner here. I want to get all the outside work finished, and get some epoxy on the floor before it turns cold (there's a minimum temperature for epoxy). The garage door has been ordered, and should come in about 3 weeks. With that the building will at last be closed off.

-RoB-

[Steve White]

Its looking good Rob :)

[Rob Beckers]

Thanks Steve! We're slowly getting there.

The torn-up electrical was spliced on Thanksgiving day (yeah, us Canadians have a different date for that than our friends south of the border), and the lights are working again. I've dug a little trench for the fixed line, so it's now sitting 20" under, at least the part that was fixed. Yesterday was spent doing some more digging, getting a nice flat surface for the insulation to be put on.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=84

Today was jig-saw-puzzle day; putting the rigid foam insulation sheets into the ground. As described, the other 3 sides of the building have already been done, only the front part was missing. How effective this is in the front is a big question mark, there's a huge cold-bridge due to the slab sticking out from under the door (concrete is a really good heat conductor). Still, since it's about as much work to do a lousy job as it is to do a good job, I figured I'll do my best and leave it at that.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=85

That's the final result. Those stones are there to hold the foam sheets down while the 'glue' cures. I use low expanding PU foam from a spay can to glue the sheets together and fill up small voids. That way they will stay put then the soil/stone is added on top of the foam. The front insulation ties in with the sheets that were already in place on the sides, so it's one continuous barrier around the building now. The front also uses 2" sheets, of R10 each, two layers, going 4 feet out from the building. As you can see from the picture, I've also put some landscape fabric in the front part where the driveway to the building goes. This is so the GA that I will get tomorrow can be tamped down with a plate compactor, without drilling it into the underlying (softer) soil. As you may recall we had huge problems with that earlier on in the build, during foundation work (and without the fabric underneath).

So, tomorrow I'll call the stone guys to deliver a truck load of 9 cubic yards of GA. The depth runs from about 15" at the existing driveway, to around 5" close to the barn (there's 4" of foam on the ground there). Then it's leveling the GA with my trusty Kubota, and running a plate compactor over it. When it comes time to resurface the driveway I'll have asphalt put in to the barn. For now it'll just be tamped GA, since they charge as much to asphalt that little piece as it costs to do half a driveway.

All this construction work has been taking its toll on my body. Besides backaches (I'm used to those), the last couple of weeks I've also had increasing pain in my right arm and hand. A visit to the doctor got the diagnosis of "tennis elbow". I have never played tennis in my life, go figure... :confused:

-RoB-

[Joe Blake]

there's a huge cold-bridge due to the slab sticking out from under the door (concrete is a really good heat conductor). Still, since it's about as much work to do a lousy job as it is to do a good job, I figured I'll do my best and leave it at that.



Would it be too late to take a concrete saw and cut a narrow slot all the way through and use the foam-in-a-can to create a "break" in the bridge?

Joe

[Rob Beckers]

The issue with cutting through the concrete is that it leaves a narrow piece, that will 'float' (the term the concrete guys used) like an iceberg on water. When a heavy object is placed on it (such as my 8700 pounds forklift), the piece will start tilting/moving. A partial cut won't work either, since it'll cause the concrete to crack all the way through. Besides that, it would take quite a cut to have an impact: Even PU foam, a very good insulator, is only R5 per inch.

I'm curious if there's a proven solution for this type of construction problem. For my barn I'm not going to make any changes now, I'll live with it, but more in general I would like to know what can be done.

-RoB-

[Joe Blake]

I'm curious if there's a proven solution for this type of construction problem. For my barn I'm not going to make any changes now, I'll live with it, but more in general I would like to know what can be done.

-RoB-


I don't know of any "proven" solution, but I wonder whether some heavy duty rubber matting, say made from recycled tyres, could be laid on top of the concrete (perhaps with bolts to hold it in place) could act as an insulator for heat, as well as absorbing some noise/ vibration as the machinery operates.

Secondly, I presume having metal reinforcement bars laid in the concrete is a requirement under building codes. I would think that that would be a "heat super highway". That suggests reinforcement bars made from a less conductive material.

Thirdly instead of having a vertical cut completely through the concrete pad, during construction create an angled break (say 45 degrees from horizontal) with integrated columns to maintain the structural integrity, but with the foam filling the gaps. The principal of the angle is employed in sloping armour on tanks etc. Although the armour itself might be only 5 cm in thickness, because of the slope any impacting ordnance strikes at an angle less than 90 degrees, therefore its path of travel means it has to go through essentially more armour. Also the tilt of the Earth's axis changes the incident angle of sun light from one season to the next, changing the amount of heat generated. So an angled break in the concrete may reduce the heat transfer from one portion of the pad to that above it.

Lastly, how about a block of concrete with a different composition, with a proportion of an insulating material that won't greatly affect its strength that will reduce heat (and possibly noise) transfer. Again, maybe finely ground rubber from recycled tyres. Or perhaps some vertical tubes filled with circulating fluid (probably not brine, since I seem to remember that salt doesn't treat concrete nicely) that will take heat from within the concrete and "dump" it near the surface of the pad, probably in an area just before the door, so that there's a sort of "heat fence" to keep some of the heat inside the building. (Perhaps have a similar fence outside as well to stop heat coming IN.) I suppose one could even use air as a heat transfer medium. If the tubes were vertical, then that shouldn't affect the compression strength of the pad very much.

A consequent thought might be to have these (sealed) air tubes mounted on an integral strip with a sufficient space between each tube to allow concrete to flow in and fill the interstices. This strip could possibly be laid in the formwork before the concrete pour. (An idea for some budding inventor perhaps? Remember you saw it here first.)

The whole concept of heat leaching out of a building via a concrete floor is actually one that never occurred to me before, since I unconsciously regarded concrete as an insulator, but now I've thought about it, concrete is usually a good material for a "heat bank" to store heat, so obviously it must conduct.

Hmm. V-e-e-e-e-r-r-y interesting.

Joe

[Steve White]

Maybe the solution is as simple as not having the concrete extend under the door. Construct it so that the floating pad stops short of the door perhaps forming an indent that frames as tightly to the closed door as possible. Or size it so that you could drop a pressure treat insert into it as a means of adjusting the space between the pad and the door. That would also give the ability to attach a replaceable rubber seal.

On the other side I could drill and pour a couple of pilings to support a concrete footer and then build a wooden or steel ramp that sits on that. The ramp would allow a degree of adjustability over the years as things settle. Basically the door when closed would fit into a slot like a pocket door. Doing this would also allow drainage to be handled pretty simply.

With a little thought and planning I think I could build a pretty nice seal to sit in the opening for the door to butt up to. Not only would it reduce the thermal bridge but it would allow for an improved air seal.

[Rob Beckers]

Last weekend was spent moving 9 cubic yards of granular-A around, and Monday I rented a plate compactor to tamp it all down. So, we now have a driveway that is somewhat hardened to the entrance of the barn. I have not tried yet to drive the forklift over it. Those little wheels and 8700 lbs make me a bit nervous, and things may compact even further after a few rain showers. This is what it now looks like.

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=86

At least all the insulation, and basically all the outside work, is now done. Today I installed a frame around the inside of the door opening, made from 2x6's. This is for the garage door guys, so they can install the garage door on it when that comes in (should be in about two weeks). Also coming in, finally, is the metal roofing that I have been waiting for since August 12th (!).:bounce: The problem is with the factory (Decra), they really don't have their act together. So, if I can line up the roofer I may actually get a real roof on there before the winter hits.

Meanwhile I'm moving on to the floor of the barn. As stated, this is to be used as a warehouse for my business and to make it easier to clean, better looking, and durable, I'm putting epoxy on the floor. A combination of primer - epoxy - polyurethane to be exact. Having that done by the pros runs around $3/sq.ft., doing it myself costs about 1/3 of that. I've done a few epoxy floors before, so I'm doing this job myself. Biggest issue is going to be the temperature; even though I can heat the inside (no door though), it's hard to get the little piece that sticks out to be warm enough for epoxy. Minimum working temperature is 13C, below that it takes a really long time for the stuff to set up. I'll put the plastic back in front of the door opening and run it to the outside. So all of the floor is 'inside', then heat it before starting the job. Due to solvents the heater can't run when the primer and polyurethane are put on (and drying). That stuff is really flammable. We'll see how it goes.

-RoB-

[Ralph Day]

Hi Rob
To heat that tongue of concrete in the barn doorway could you tarp the opening...extend the tarp onto the gravel and hang an electric radiant heater (quartz tube type) directed at the tongue? That would be a non-combustible heat source during the paint cure.

The building looks good. Is it all for Sirroco's or are you getting into the RE materials game in a big way? If you are, I'm down to 5 working Hydrocaps out of 24 and can't find a supplier anywhere! Just a thought.

Ralph

[Rob Beckers]

Hi Rob
To heat that tongue of concrete in the barn doorway could you tarp the opening...extend the tarp onto the gravel and hang an electric radiant heater (quartz tube type) directed at the tongue? That would be a non-combustible heat source during the paint cure.


Hi Ralph, yeah, that would work. If I had an electric heater... :sad2:
For now I'm hoping for a bit of luck with the weather, a few more warm days when the time for coating the floor comes. I'll tarp off the opening as you say, and run the heater so the slab is not stone-cold. Come to think of it, the only problem is the PU top-coat. It uses a combustible solvent. The primer is water based epoxy, and the bulk-coat is 100% solids epoxy (so no solvent at all).


The building looks good. Is it all for Sirroco's or are you getting into the RE materials game in a big way? If you are, I'm down to 5 working Hydrocaps out of 24 and can't find a supplier anywhere! Just a thought.
Ralph

The building is somewhat multi-purpose, with an emphasis on business use. The Sciroccos are fairly large (and a few of those are currently taking up my garage, with winter coming I want the turbines out and the cars in!), the upcoming 25 kW from Eoltec will not even fit in my garage. I can't use the forklift in the garage, because the door opening is too low. So it's currently sitting outside. The new barn will solve that. Besides the wind turbines, there are plans to start importing solar panels (photovoltaic panels). The new building will allow me to slowly grow the business.

As to your Hydrocaps; send me a PM with the details (for what batteries or opening size they are intended). I'll ask my battery guys what they have available.

-RoB-

[Rob Beckers]

With the unseasonably warm weather we're having I am using the opportunity to put epoxy down on the floor. That is a long and, quite literally, painful process. Since it is not really on topic for this forum I'm posting the details what I'm doing on a garage floor forum (http://www.garagejournal.com/forum/showthread.php?t=24242). Anyone interested can follow along on there. Once it's done I'll post pictures here.

-RoB-

[Rob Beckers]

The impossible has finally happened: We have a roof and a door! :nuts:
Well, almost. The garage door guys didn't bring the motor, nor the weather stripping to seal up the sides. They also told me they are really very, very busy and didn't know when they would be back. After impressing upon them how long I had been waiting and how much I needed this job to be done they agreed upon Wednesday to finish things up. After having lived in the US for 12 years it always strikes me how much not serious businesses in Canada are. They absolutely take their customers for granted. :mad:

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=110

The metal roofing material came mid November. Keep in mind that this was ordered in August, with a delivery promise of the first week of September!! :evil: My roofer put me on his schedule for November 28th, but bad weather pushed jobs forward, including mine. So he has been working on the roof last week, and today, a total of 4 days of roofing. Today started with a temperature of -22C this morning, and the guys just finished their work, at a balmy afternoon temperature of -14C. I have rarely seen two guys so happy to go home!

http://www.greenpowertalk.org/picture.php?albumid=3&pictureid=111

The roof does look good though! These are the metal Decra shingles, with 50-year warranty. In other words, my sincere hope is that I will not be re-roofing during my lifetime. In terms of price it pretty well runs twice as expensive as regular 25-year shingles. Since 25-year shingles normally last about 15 years in our climate I recoup this investment with one reshingling job, or in 15 years.

Now the wait is for the door to be finished so it is working. When that is done I can finally call in the inspector for final inspection. The inspector told me in no uncertain terms that he does not want me to use the building until he has inspected it (and he needs both a roof and door before doing final inspection).

The end is in sight.... :pray:

-RoB-

[Aawebdev Piter]

You can slash energy costs by up to 50%. Because SIPs create a tighter building envelope than conventional insulation, your builder can actually reduce the size of heating and cooling equipment. That reduces costs immediately. Better yet, SIPs keep your costs down from season to season, year after year, for as long as you own your home.

[Penny Walters]

That all are very interesting project.

What do you think about the Earth house. Do you think are sustainable as it should be?