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Brian Bravenec Posted: Aug 03, 2009 11:16 PM	"Retrofitting" a new house This is my first post, and I am hoping some of y'all who have been doing this stuff for a while can help me out. My wife and I are trying to purchase a new home that is currently under construction. The homebuilder is an individual who builds custom homes, but alot of his work is variations/modifications to an existing plan that he's done before. Still, the quality of his work is undeniable. For whatever reason, though, energy efficiency is not high up on his list of priorities when he builds one. There is no radiant barrier, no tyvek, no foam - just batting and blown in insulation which on a 5,000 square foot house isn't going to cut it for me. The home is currently framed with electrical, plumbing, and hvac in place - not yet insulated or bricked. He used thermoply and osb on the exterior. It has 3 AC units and I cannot tell the tonnage of each but they each supply roughly a third of the home and the zones are fairly logically distributed/even. I don't know for sure, but I the pitch of the roof looks about 10:12, maybe 12:12 if that matters, and the shingles are black - pitch black. We would like to have him contract with someone local to install spray in foam before he drywalls the home. I was hoping to have the roof deck sprayed as well but I have a few questions/concerns. 1) I know that if we use foam, that the home is way over supplied by the 3 AC units and I'll have to fiddle with using 2 of them or something to that effect. Will AC suppliers sometimes "buy back" a unit so that I could downsize? Is it that difficult to re-route some of the duct work (ie one unit for downstairs and leave the one for the upstairs alone)? 2) The current AC units are most likely not contained combustion or whatever the term is that allows one to completely seal the home (the magic number is 90, but I cannot recall the correct terminology). Would it be a waste of money to foam the house and roof deck if I can't seal it anyway? I think it will have blown in fiberglass regardless. 3)Our temps in the summer are 100+ and the winters usually get down into the 30's, sometimes into the 20's but not usually. Do I need to be concerned about condensation? 4) The darn shingles are pitch black, and I read here that foaming the roof deck raises the temp of the shingles by perhaps 3 degrees and has been shown to have no effect on the lifespan/function of the shingles while color does. The roof faces east/west so it's gonna get hot no matter what. Are shingle/roofing guys giving your clients a hard time about foaming the roof deck in terms of warranty? Thanks for any input. I essentially want to know if I'd be wasting money trying to do this and how I should go about it to make it financially worthwhile in the long run. Take care----
Michael Fusco Posted: Aug 23, 2009 01:45 PM	wow....no help for almost a month. Ok...... 1. Never heard of any buyback program 2. I think you are talking a bout the heating. You might be talking about sealed comsbustion chambers usually available only on 85%+ AFUE units. You can still do a closed attic...talk to your foamer and code official. 3. Not if the job is done correctly 4. Depends on the shingle manufacturer (Certainteed definately not...they sell foam!) By the way.....get a HERS rating done on the house. It will open your eyes!! (should cost about $700 if you find a local guy....not much against the possible savings!) Hope that helps
Gerry Wagoner Posted: Aug 23, 2009 02:31 PM	Spray foam on the house and you'll love it. Go with fiberglass and you'll forever regret it. regards. og

Author

Comments

Brian Bravenec

Posted: Aug 03, 2009 11:16 PM

"Retrofitting" a new house

This is my first post, and I am hoping some of y'all who have been doing this stuff for a while can help me out.

My wife and I are trying to purchase a new home that is currently under construction. The homebuilder is an individual who builds custom homes, but alot of his work is variations/modifications to an existing plan that he's done before. Still, the quality of his work is undeniable. For whatever reason, though, energy efficiency is not high up on his list of priorities when he builds one. There is no radiant barrier, no tyvek, no foam - just batting and blown in insulation which on a 5,000 square foot house isn't going to cut it for me.

The home is currently framed with electrical, plumbing, and hvac in place - not yet insulated or bricked. He used thermoply and osb on the exterior. It has 3 AC units and I cannot tell the tonnage of each but they each supply roughly a third of the home and the zones are fairly logically distributed/even. I don't know for sure, but I the pitch of the roof looks about 10:12, maybe 12:12 if that matters, and the shingles are black - pitch black.

We would like to have him contract with someone local to install spray in foam before he drywalls the home. I was hoping to have the roof deck sprayed as well but I have a few questions/concerns.

1) I know that if we use foam, that the home is way over supplied by the 3 AC units and I'll have to fiddle with using 2 of them or something to that effect. Will AC suppliers sometimes "buy back" a unit so that I could downsize? Is it that difficult to re-route some of the duct work (ie one unit for downstairs and leave the one for the upstairs alone)?

2) The current AC units are most likely not contained combustion or whatever the term is that allows one to completely seal the home (the magic number is 90, but I cannot recall the correct terminology). Would it be a waste of money to foam the house and roof deck if I can't seal it anyway? I think it will have blown in fiberglass regardless.

3)Our temps in the summer are 100+ and the winters usually get down into the 30's, sometimes into the 20's but not usually. Do I need to be concerned about condensation?

4) The darn shingles are pitch black, and I read here that foaming the roof deck raises the temp of the shingles by perhaps 3 degrees and has been shown to have no effect on the lifespan/function of the shingles while color does. The roof faces east/west so it's gonna get hot no matter what. Are shingle/roofing guys giving your clients a hard time about foaming the roof deck in terms of warranty?

Thanks for any input. I essentially want to know if I'd be wasting money trying to do this and how I should go about it to make it financially worthwhile in the long run.

Take care----

Michael Fusco

Posted: Aug 23, 2009 01:45 PM

wow....no help for almost a month.

Ok......

1. Never heard of any buyback program
2. I think you are talking a bout the heating. You might be talking about sealed comsbustion chambers usually available only on 85%+ AFUE units. You can still do a closed attic...talk to your foamer and code official.

3. Not if the job is done correctly

4. Depends on the shingle manufacturer (Certainteed definately not...they sell foam!)

By the way.....get a HERS rating done on the house. It will open your eyes!! (should cost about $700 if you find a local guy....not much against the possible savings!)

Hope that helps

Gerry Wagoner

Posted: Aug 23, 2009 02:31 PM

Spray foam on the house and you'll love it. Go with fiberglass and you'll forever regret it.

regards.

og

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