I am being baraged by foam insulating firms since I checked into their product, but I need independent analysis of what they have to sell. It is very expensive stuff. Bids are higher than fiberglass bids by almost a factor of three and, at those prices, I need to see cost/benefit/payback period analyses.
Our house is being framed on 2 x 6 w/ one inch rigid sheathing (taped at joints) w/ Tyvek housewrap. All the window and door flanges have been taped. The roof rafters have been draped w/ radiant barrier. the house has a pier & beam foundation of TJIs w/ vents at approx every 4 feet. The windows are Andersen. The roof is Garard Stone-Coated Steel, which means the roof system stands off the roof deck about 2 inches. The roof ridge is vented as will be the soffits. I have planned on two Trane heatpumps of the highest efficiency possible (2-story w/ one unit up and one down).
The foam guys say I can reduce the tonnage of my HVAC. One significant claim of the foam people is that they create a good envelope. Seems like I have done that w/ the tape on the rigid and housewrap. They also say I don’t have to totally fill the stud bays as the stopping of the air movement eliminates the need for so much foam. I know that air can move around insulation. I do like the fact that the foam fills in around the boxes and the like, but I here there is a product called Optima that also does that for a lot less money. It is also sprayed in.
Can anybody help me sort through the hype? I am in humid East Texas, where the July high is 96 (76 at night) and the Jan. high is 57 (36 at night).
Replies
"I am in humid East Texas, where the July high is 96 (76 at night) and the Jan. high is 57 (36 at night)."
" I have planned on two Trane heatpumps of the highest efficiency possible (2-story w/ one unit up and one down)."
You might want to verify this, but I have "heard" that the way that SEER is spec'd that it does not account for dehumidification. Thus you will end up with cold, humid, clammy air.
I did a google and this is the first site that came up.
http://www.houston-air-conditioning.com/customized_humidity_control_system.htm
As to your orginal question you might want to get you house energy star rated. I think that some of the people that do that can evalutate the different products and give you payback information.
http://www.texasenergypartnership.org/
I have not gone through this web site to see if this is for residential or commerical. But do some checking. Some utilities and states have rebates/tax incentives for getting it rated.
Here are a couple of other sites that might help you .
http://www.hersraters.com/
http://www.seco.cpa.state.tx.us/seco_links_tips.htm
http://eslsb5.tamu.edu/sbill5/default/index.shtml
Thanks so much for your prompt and thorough response.
scenario may be different down texas way but the foam really pays for itself in northern stormy, windy climates. You definitely wouldn't need more than three inches in walls, two is probably enough. The Cor-Bond people have scads of solid studies and information. I seems to me that in a cooling climate such as yours, you would want closed cell foams such as corbond or other urethyne foams.
I do pay about 2-1/2 times as much, in comparison to fibreglas but get more for it. No wind blows through, Clients get to brag about their energy bills, and as a side benefit, they love how quiet it makes the house. That would be a big seller if yours is under the airways or on a high traffic street or a noisy neighborhood..
Excellence is its own reward!
Urethane or icinene. Not sure I spelled that second one right . Urethane is a closed cell foam and thus cannot absorb moisture. Icinene is an open cell foam. Urethane has the greater R value of the two, it is also more expensive.
Your taped tyvek may help with air and maybe water intrusion from the outside but it should not be confused with the air/vapor barrier needed on the inside.
I am fairly familiar with cold climate building, but not familiar enough with with the cool house and hot humid outside conditions and the issues it may cause. We get both here in MN., but there is not as much published research on hot climate moisture issues.
If I could take my pick I would go with the urethane. I think it is the best, but unfortunately also the most expensive.
Hold up on that vaporbar advice. He is in a cooling climate which requires the vaporbar on the outside, not the inside. Which is all academic since no VB is needed with foam. It eliminates drafts and dewpoints. Also, a urethyne foam IS a VB.
Excellence is its own reward!
Hold up on that vaporbar advice. He is in a cooling climate which requires the vaporbar on the outside, not the inside. Which is all academic since no VB is needed with foam. It eliminates drafts and dewpoints. Also, a urethyne foam IS a VB
. Excellence is its own reward!
Thanks! Vapor barriers, based on my own research, are not recommended in East Texas. In the wintertime the cold and hot sides swap quite often. My rigid and the Tyvek should eliminate most of the drafts. That's kind of why I wonder if the wrap and tape may replace a lot fo what the foam does. I temporarily live in a building I built w/ 2 x 6 framing and the same type of insulation It is very quiet and we just don't seem to ahve drafts of any kind. in fact I can't say I've ever even given a draft a thought.
Also, a urethyne foam IS a VB
Technically it's not. It still requires a paint layer to meet level I status.
Having said that, I wouldn't want to have to suck air through it to survive. Also there's no difference in the cost between the two. The difference is local markets.
still the best insulation/sealer on the market.
Gabe
Edited 6/7/2003 4:09:28 PM ET by GABE_MARTEL
Edited 6/7/2003 4:10:52 PM ET by GABE_MARTEL
For some unknown reason, on my screen when I read my post to Piffin, only the top line in red appears and not my comments below it. If I try to edit, I see the entire message, I then apply it but only the top line appears again.
Bottom line is SIP foam in NOT classified as a level 1 vb. It still requires to be painted over.
Regardless, it's still the best method of insulating and sealing a home or building at this point in our century.
Gabe
Gabe,
It reads fine from here.
True that's it doesn't have the same perm rating as a plastic VB but from practical viewpoint, combined with the elimination of dewpoints, it does eliminate the need for an additional VB. It's permeability rating is nearly as good as some roofing materials, so I trust it as a VB..
Excellence is its own reward!
I agree with you 100% but I'm thinking code and not reality. I personally wouldn't waste money on an extra layer of paint and I'm confident in the product's ability to seal better than any layer of poly installed in any house in today's world.
I get a couple of hundred thousand square ft. done every year and the one thing that never happens is a call back.
Gabe
I've had to call them back a coupole times before sheet rocking. When you spray against a cold plywood sheathing and it's below zero outside, you can get a couple bays that shrink back and split apart. We do all we can to pick a warmer day and really pour the heat to it for a day or two before spraying but there are always some cold spots. That foam does the same thing your cahonne`s do when coming into contact with something that cold!.
Excellence is its own reward!
You can easily spray foam at temperatures well below 0 degree Centigrade. The installer has to be trained for cold weather adjustments in the mixture. Polyurethane is produced when isocyanate and a resin are mixed together in the spraygun's mixing chamber. This produces an exothermic reaction. This produces heat as well. The heat produced by this chemical reaction causes the foaming agent to vaporize, creating increased foam expansion. The entire process is dependent on the type of formulation and it is important that the application of the foam be completed before it becomes rigid.
If the panels you are spraying are dry and not covered with moisture in the form of frost, adhesion will be complete and should stand the thermal movement of the substrate during the application and drying or setting process of the foam.
Gabe
Being south of the border that separates us, I was refering to blow zero degrees Fahrenheit. The particular application i have in mind was applied with exterior temps of nearly minus 20°F with wind blowing against the exterior sheathing on the sidew that showed minor failure.
Ideally, I agree with you in theory but in practice, nothing is perfect. So it can flash before it adheres in such extreme circumstances. No problem to just touch up later. .
Excellence is its own reward!
Urethane or icinene. Not sure I spelled that second one right . Urethane is a closed cell foam and thus cannot absorb moisture. Icinene is an open cell foam. Urethane has the greater R value of the two, it is also more expensive. OK.
Your taped tyvek may help with air and maybe water intrusion from the outside but it should not be confused with the air/vapor barrier needed on the inside. Tyvek is an air barrier and not a moisture barrier. Actually my rigid insulation is what is taped and that contributes to minimizing the air movement.
I am fairly familiar with cold climate building, but not familiar enough with with the cool house and hot humid outside conditions and the issues it may cause. We get both here in MN., but there is not as much published research on hot climate moisture issues. What little I have read tells me that vapor barriers are not recommended in our area because of the significant swapping of the warm and cold side in the winter.
If I could take my pick I would go with the urethane. I think it is the best, but unfortunately also the most expensive. OK. Just wish I could find some solid research on the whole subjec. For example, does my taped rigid, coupled w/ Tyvek do what the foams to to some degree or other?
Thanks!
It's Icynene, just in case you want to put it in your spell checker...
http://www.icynene.com/index.asp
Can't tell fro your post if you are a pro or a DIYer. If you are interested in doing the job yourself go to ths web site http://216.15.214.22/about.html and order the foam and do it your self.
I did it and it works great.
Good Luck
Thanks for the tip.
I'm a DIYer and think I could handle a job like this. I'll read up on it. I imagine there's a lot of markup in the product.
Mike: This isn't something you can do yourself. The equipment needed to handle the product is expensive & the chemicals hazardous. You need full level A chemical suit protection. This requires a full non permeable suit, a mask and external air supply. Not a DIY friendly task.
Our roof is a lot smaller than yours. Only about 10 squares, but it is a hip style gambrel w/ 5 dormers. Set us back about $11K, and the contractor wrapped the job in his shirt to deliver it - took better than a week to install, and they went berserk w/ all the dormer work and the joint where the gambrel changed slope. Week after it was complete we had a pretty bad thunderstormsystem come through and rip off a bunch of roofs - ours just laughed at it. Amazingly quiet in a heavy rain, also. Doesn't sound at all like you are under a washtub w/ someone beating on it w/ a hammer.
DonThe GlassMasterworks - If it scratches, I etch it!
You're the one from Nawth Jawja, right. Glad to hear the rood held up. I'm sure you're right about spraying the foam myself. I imagine it is also somethin one has to get the ahng of. Thanks for all your input
Mike: I live in Nawth Jawja, about halfway between Etlanner & Chat'nooga. Our climate approximates yours. I built (am building) a house very similar to yours - Garard roof, heavy insulation, etc. I put urethane in mine last summer on the hottest day in July. It is an amazing product. The day it was done, the aplier had to wear full level A protection, and lost a ton of weight to sweat. Temp in attic was near 130 degrees, F. We had the foam run right up the rafters, including the attic in our "Conditioned space." The next day the temp in the attic was a balmy 82 degrees F with the same sun intensity. See if you can con your inspector into letting you do it that way. If you have a unit in your attic, it will bake in the heat and cost you a fortune to run for marginal results.
Interesting winter and spring. We are just now finishing up the house. We have a functioning A/C unit - a Carrier dual fuel w/ computer operated active zoning and a continuously variable speed DC fan. The temp hit some pretty cold levels last winter. In the fully insulated house, the temp never dropped below 45. Our trim carp bellyached, but it was below 20 outside. Come spring, we had never dropped below 45 inside, without using the A/C unit. Finally, two days ago we finally started using the A/c on cool. Temp got up to 78 inside, but the humidity was what was killing us. A/C came on, ran for a while, then shut down and coasted. Temp stayed steady at a comfy level.
I think it is critical to include the attic in the conditioned space. If you have ducts up there, they are only insulated to about R-6. In a space that will vary from 130 down to whatever outside air temp you have in winter. That positutely inhales very sharply (that means "sucks" to those who don't read Bill Buckley.) I was lucky - my county inspector agreed w nearly zero argument to convince him. He wanted to come back on a hot day to see what the attic was like. He was impressed.
The Urethane has that place so sealed up we will have to open the doors hourly to get air exchanges. We have built in capability to add an air heat exchanger if it turns out we need it. That little jewel will set us back another $1200, according to our HVAC contractor.
I have noticed some separating between urethane and rafters after about 9 months, so I routinely take my foam gun and fill the voids. Contractor agreed to about 2 inches, but we wound up w/ about 4 in most places.
BTW - we love our Garard roof. The two inch stand-off makes a big difference in temp of the roof deck. We have two penetrations for solartubes for lighting; the tubes are not yet installed. Where the penetrations are, the temp is about 20 degrees warmer than under the rest of the deck, so the roof itself helps a lot.
Good luck w/ yours. Go w/ the urethane - the up front cost is staggering, but the payoff is tremendous. Not just in utilities costs, but in comfort. How much is that worth?
I got a lot of advice from Gabe Martel, and it was all valid and worthwhile.
Don
Mike: I live in Nawth Jawja, about halfway between Etlanner & Chat'nooga. Like your humor. My sis live in Stone Mountain and my folks on Lake Oconee. Our climate approximates yours. I built (am building) a house very similar to yours - Garard roof, heavy insulation, etc. I put urethane in mine last summer on the hottest day in July. It is an amazing product. The day it was done, the aplier had to wear full level A protection, and lost a ton of weight to sweat. Temp in attic was near 130 degrees, F. We had the foam run right up the rafters, including the attic in our "Conditioned space." The next day the temp in the attic was a balmy 82 degrees F with the same sun intensity. See if you can con your inspector into letting you do it that way. If you have a unit in your attic, it will bake in the heat and cost you a fortune to run for marginal results. We are so rural that there is no such thing as inspections. Only thing you need license for is septic. Nevertheless I am going according to code and then some.
Interesting winter and spring. We are just now finishing up the house. We have a functioning A/C unit - a Carrier dual fuel w/ computer operated active zoning and a continuously variable speed DC fan. We will use American Standard (same asa Trane) heatpimps. Propane is up to $1.35 per gallon here. If I spray foam in the attic it will be over the ceiling sheetrock. I ahve radiant barrier over the rafters and it goes a long way in keeping the house cool on hot days. We're in the dry and wired (HVAC and finish plumbing is next) The temp hit some pretty cold levels last winter. In the fully insulated house, the temp never dropped below 45. Our trim carp bellyached, but it was below 20 outside. Come spring, we had never dropped below 45 inside, without using the A/C unit. Finally, two days ago we finally started using the A/c on cool. Temp got up to 78 inside, but the humidity was what was killing us. A/C came on, ran for a while, then shut down and coasted. Temp stayed steady at a comfy level. Our temporary residence is R-30 plus in the ceiling and almost R-30 in the walls. When we set the AC up to 85 when we leave it usually will only get up to about 80. We have a programable thermostat (Carrier' best) and they are great.
I think it is critical to include the attic in the conditioned space. If you have ducts up there, they are only insulated to about R-6. I've been told that spraying rigid ducting is a good idea. In a space that will vary from 130 down to whatever outside air temp you have in winter. That positutely inhales very sharply (that means "sucks" to those who don't read Bill Buckley.) I was lucky - my county inspector agreed w nearly zero argument to convince him. He wanted to come back on a hot day to see what the attic was like. He was impressed.
The Urethane has that place so sealed up we will have to open the doors hourly to get air exchanges. We have built in capability to add an air heat exchanger if it turns out we need it. That little jewel will set us back another $1200, according to our HVAC contractor. Where does the heat exchanger install?
I have noticed some separating between urethane and rafters after about 9 months, so I routinely take my foam gun and fill the voids. Contractor agreed to about 2 inches, but we wound up w/ about 4 in most places.
BTW - we love our Garard roof. The two inch stand-off makes a big difference in temp of the roof deck. We have two penetrations for solartubes for lighting (My wife insisted on two of those also. They are nice); the tubes are not yet installed. Where the penetrations are, the temp is about 20 degrees warmer than under the rest of the deck, so the roof itself helps a lot. We've had great domments on our roof. It's a Barcelona pattern which looks like Mexican barrel tile. 72 squares and about $26k later. They had it on in two days flat.
Good luck w/ yours. Go w/ the urethane - the up front cost is staggering, but the payoff is tremendous. Not just in utilities costs, but in comfort. How much is that worth?
I got a lot of advice from Gabe Martel, and it was all valid and worthwhile. Who is Gabe Martel?
Don
The GlassMasterworks - If it scratches, I etch it!
Gabe is a righteous Canadian Project Manager, directing the works as multiple hundreds of thousands of dollars are turned into liveable and workable structures and facilities. He's the guy who makes sure that it's done right.
now if we could just get the politicians to listen to him....
Excellence is its own reward!