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Quality control in foam sealing SIP house
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retro
New Member
Posts:3
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| 31 Dec 2006 01:05 PM |
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We have a house and separate garage TimberFrame + SIPs in a cold climate, starting to be dryed-in. SIP maker was also installer. Roofs were OSB on both faces, + blue-board. Each building has 2 shed dormers. Garage roof overhangs, house roof ends flush. Garage roof leaked heavily in rain, installer added some foam, it rained again and leaked in fewer places. At least we know the roof isn't airtight. GC was slow (weeks) in covering roof. House was built in a sunnier stretch of weather and the roof was quickly covered. Later we had a leak where a roof (like an apron) below a dormer attached to the dormer wall - a vertical joint probably not well sealed.
We now, weeks later, found mold growing at lowest point in dormer roof of garage. Installer says it's probably a cold spot, we agree, maybe the 10" overhanging blue-board gets plenty cold and the corners attract moisture via vapor drive.
So two questions: (1) I now think it may be a bad idea to expose blue board / sheet rock to the outdoors, as it will be a thermal bridge and an absorbent one at that. Opinions? (2) Am I over-reacting if I think the installer was too casual in how they applied foam sealant between panels, between roof and wall panels, etc.? If the garage leaked water, the house probably will leak air. And we have spent $$$ for passive solar, where I believe controlled air exchange is important. Additionally, I am worried about rot where leaky seams and vapor drive and cold climate keep dampness somewhere near the walls and roof.
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PanelCrafters
Advanced Member
Posts:680
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| 31 Dec 2006 02:08 PM |
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Posted By retro on 12/31/2006 1:05 PM
(1) I now think it may be a bad idea to expose blue board / sheet rock to the outdoors, as it will be a thermal bridge and an absorbent one at that. Sheet rock for sure. Blue board should also be concealed.
(2) Am I over-reacting if I think the installer was too casual in how they applied foam sealant between panels, between roof and wall panels, etc.? Nope. It's your new house isn't it?
Additionally, I am worried about rot where leaky seams and vapor drive and cold climate keep dampness somewhere near the walls and roof. Once the windows(and doors) are installed, have a blower door test performed. Seal any leaks at that time. Also, did the installers use SIP seam tape to cover all of the SIP joints in the walls, and ceilings? Now, if the panels were correctly installed and the the seams properly sealed, seam tape would be redundant. However, sometimes it's difficult to tell if a seam is indeed sealed properly, and the seam tape is 'insurance'. For the ultimate in insurance, consider using strips of ice & water shield over the exterior seems. |
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| ....jc<br>If you're not building with OSB SIPS(or ICF's), why are you building? |
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Scott101
New Member
Posts:30
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| 31 Dec 2006 05:15 PM |
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I am not a builder or engineer, but I have installed my share of roofs. I read your post and am not sure if your final roof cover is on both structures. If they are, it sounds like you have some major flashing issues, let alone air leaks. I can understand having some bad joints where the expanding foam did not completely seal, but if rainwater leaked into the house (or garage) through the roof, that to me is a serious issue. Spaying foam into a panel jont fixes (or redirects a problem elsewhere). The water is still getting in and will find some other place to collect and cause rot, mold, etc.
I agree with Panelcrafters, SIP joint tape is good insurance. However, if you have water penetrating and collecting between your OSB roof deck and finished roof deck, you will still experience rot/mold problems. I have specified self-adhesive ice/water shield on my entire SIP roof, since the SIP panels are so difficult to replace.
Once you know that your exterior leak problems have been resolved, a blower test and infrared thermographs are needed to isolate the air leaks.
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panelwright
New Member
Posts:31
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| 05 Jan 2007 08:21 AM |
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Bulk water management and air-sealing are two seperate issues. Treat them as such.
Pre-appling gypsum (blue or any other color) is a bad idea. Why? Because it prevents proper sealing of the joints!!! In addition, it's nearly impossible to avoid installation and handling damage that will make your finisher cringe.
Just as a timber frame elements and decking shouldn't penetrate the SIP envelope, neither should your gypsum. It's not about thermal bridging. It's about air-sealing!!!!
If water gets into the joint during construction (It does 90% of the time arond here) give the water a chance to get out before sealing it up with SIP tape. Especially if your taping the interior of the panels with an inpenetrable SIP tape.
DO NOT seal both sides of the joint!!! Ice & water shield on the outside with SIP tape on the inside is a bad idea!!!!
It violates the second rule of bulk water management (If it gets in, give it a way to get out)
An educated installer is worth the $$$
Al Cobb |
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PanelCrafters
Advanced Member
Posts:680
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| 05 Jan 2007 04:30 PM |
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Posted By panelwright on 01/05/2007 8:21 AM
DO NOT seal both sides of the joint!!! Ice & water shield on the outside with SIP tape on the inside is a bad idea!!!!
It violates the second rule of bulk water management (If it gets in, give it a way to get out) Well Al, I guess that we've reached a point of disagreement. I call it a 'defeatist' attitude. If you prevent water from encroaching onto the envelope in the first place, you wouldn't have to worry about it, would you? Shouldn't a SIP joint be airtight in the 1st place? "Well yes, but if water gets into it, it must be able to breathe". To me that's just plain silly. And what about roof panels? Aren't they sealed at the top by the roofing materials? Brought to you by Tyvek, "Screw it up all you want....We'll Dry you out!" |
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| ....jc<br>If you're not building with OSB SIPS(or ICF's), why are you building? |
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retro
New Member
Posts:3
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| 05 Jan 2007 06:15 PM |
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fwiw, the manufacturer / installer strongly recommended against placing a watertight seal (e.g. Ice and Water Shield) on the outside, and this agreed with Joe Lstiburek's (Building Science) "Builder's Guide to Cold Climates" so I trust it. We have a cold roof and have a drainage plane under sidings and pre-painted all siding materials, all on the principle of "it WILL get wet so don't prevent it from drying."
The builder and panel people don't feel that the blue-board is a problem, but they have told me I need to get relative humidity down.
It is possible I imagine to put 1/2" plywood strips along the center of timber beams and rafters to take the load, and keep the blue board inside of these strips, foaming outside. This would give you pre-installed finish but could block moisture flow to the dew point (if you're lucky and don't live at too cold a place).
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panelwright
New Member
Posts:31
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| 05 Jan 2007 11:31 PM |
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Not to worry JC, One man's 'defeatist' attitude is another man's Realistic attitude.
Try as we might, you, I and all the panel heads of the industry will never seal an entire panel structure 100%. and if we can agree on that, I'm sure you'll agree that more then a few panels have seen a rain shower or two prior to the roofers arriving on site.
Roofing provides protection from bulk water. It does not seal your roof panel joints unless part of your roofing detail is a complete coating of peel & stick. A typical felted roof will endure the presence of residual moisture from condenstate quite often when the weather conditions are just right. This moisture can and often does cause edge swelling of an unprotected panel edge as the moisture will accumulate under the felt. It also drys out as the weather conditions change. This ebb and flow of moisture are proof that air moves freely through a typical roof assembly. It is certaintly not designed to seal the SIP joint in terms of air flow.
Your attitude towards Tyvek is regrettably understandable.
If you would like to go another round, I can only respond with pictures. Three jobs, three roofs, with three seperate installers who used SIP tape on the bottom and Grace on the top. Oh, that's right you can't post pictures on this site. I'll see you in Orlando in February. we'll discuss it further over a cold one. I'm buying.
AL
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PanelCrafters
Advanced Member
Posts:680
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| 06 Jan 2007 11:58 AM |
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Posted By panelwright on 01/05/2007 11:31 PM
If you would like to go another round, I can only respond with pictures. Three jobs, three roofs, with three seperate installers who used SIP tape on the bottom and Grace on the top. Oh, that's right you can't post pictures on this site. There's that attitude again! %^).  So, I guess what you are saying is that it's impossible to seal a SIP roof properly? |
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| ....jc<br>If you're not building with OSB SIPS(or ICF's), why are you building? |
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tah
New Member
Posts:17
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| 11 Jan 2007 08:40 AM |
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Sometime Ice & Water Shield on the whole roof cannot be avoided. In High snow climate you must have full ice & water shield.
Because what is worst than vapor condensation is directly getting the whole panel wet all winter long.
The conservative solution is to put ice & water shield down, and cover that with EPS or XPS foam to raise the roof surface above condensation temperatures (~40 F)
There is an argument that SIPs, if carefully detailed won't leak heat - since they have such low permenance, that little vapor move throught the panels - they will have to dry to the inside .
The important problem is the joints. Though I guess everyone is feeling conservative after Jueno. Anyway heres a similar detail with a foamed in framed roof:
http:www.buildingscience.com/designsthatwork/verycold/profiles/aspen.htm
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retro
New Member
Posts:3
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| 14 Jan 2007 08:52 AM |
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Thanks for the replies...
All this led me to wonder how one can attain excellent quality control in a speed-oriented operation. By "speed oriented" I mean one where crew and crane costs force an installer to
be as efficient (fast) as possible - even the crane is operated quite rapidly. Quality control in panel installation is somewhat easy - if you omit a panel, there's this 4-foot by 20-foot hole in your roof.
But foaming is essentially invisible. OK, you see the little foam muffins every foot or so along the seams, so you won't miss an entire section, and these "muffins" and the behavior of the foam
are clearly positive factors. But, given the crew's focus on efficiency, I think there must be some "pressure" that leads to a glitch here and there. So how can an installer set up an operation
that resists the pressure to be (possibly too) fast?
I experienced two indicators of quality glitches - one being rain coming through the roof and the other being a spot inspection, cutting into seams and looking in to make sure the foam is
deep (I found some only 3/4 inch deep from the outside, in a 6.5" by 1/2" gap). But discovering a glitch isn't the same as preventing it in the first place.
Thinking theoretically (and remember I am a homeowner not a professional, and I have no real experience in quality control) it occurs to me that there may be some management practice
or something that can be set up to counteract the "speed" pressure in foaming. One might be a collection of standards (e.g. how many cans to use per 100 feet of seam). Another might be
some fussy accountability arrangement (foamers sign a paper saying they performed according to standard, and they pay somehow if a spot inspection discovers otherwise - I don't like this
negative approach), another might be simply spot inspections, another might be separately managed teams (foam is applied by a separate team measured differently from the panel installing team)
I don't particularly like any of these ideas, but I do think there must be "efficiency pressure" that calls for some counterpressure.
-- This is only important to me because I am attempting a passive solar installation, which (from my reading) calls for high degree of integrity so that air flow can be controlled rather precisely. |
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jkc746
New Member
Posts:2
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| 14 Jan 2007 12:54 PM |
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Hello all,
I will soon be in the drywall phase of building. I used sips for my walls and roof and I have been pretty satified with my decision to go with sips. However
there are a few thing that didn't like in the process. What retro talks about is one of them. I felt that the crew was in to much of a hurry when applying
the glue to the splines just before setting the panels. I had the understanding that when the crew was finished the seams would be 100% sealed, however I was
told that the crew was responsible for bigger gaps but it was up to me to seal the small gaps. At the time I didn't think it was a big deal because I knew I would
do a better job than they would do. I just didn't realize how much time and caulk it would take.
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PanelCrafters
Advanced Member
Posts:680
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| 14 Jan 2007 01:45 PM |
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Posted By jkc746 on 01/14/2007 12:54 PM I had the understanding that when the crew was finished the seams would be 100% sealed, however I was told that the crew was responsible for bigger gaps but it was up to me to seal the small gaps. The crew should've been fired on the spot. It's kinda like a plumber telling a customer, that he'll take care of the big leaks, but the small ones are your problem. |
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| ....jc<br>If you're not building with OSB SIPS(or ICF's), why are you building? |
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| You are not authorized to post a reply. |
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