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Scott Plantier Posted: Aug 09, 2007 10:29 AM	RetroFoam wall and OC closed attic Hi, I'm a carpenter redoing an old plank /framed home. 2" and 3"cavities for the plank and I'm considering Retrofoam to retain interior finishes (horsehair plaster and lath.) Retrofoam is R4.6 with: Perms Per Inch of 6.631 Permeability 270C/50% UR µ=3.36 Surface Absorption <1% by vol. ASTM E96 PM/MAT I have lap siding over 2" planks a 2 or 3" void then plaster and either wall paper or a primed and latex top coated finish. The attic is planned for 6+ of Icynene with all framing members wrapped to eliminate thermal voids. (an OC the forum is familiar with) Where's everyone stand on this and what is the situation of suits for these closed attic spray jobs? Am I headed the wrong way all together?
philip mullins Posted: Aug 09, 2007 07:35 PM	i personaly would recomend closed cell (rigid) foam, especialy in an unvented attic system. but open cell is still leaps and bounds better than fiberglass. though it does not stregthen or seal nearly as well as cc. since you mentioned the foam company you have chosen i can only guess that you have been told that cc will crack, and that all other products available are junk and thiers is great. the truth is that all oc foams are very similiar and the biggest factor in performance is in the quality of the installation. sounds to me like you are doing a top notch restoration. and you are doing rite to research a little before moving ahead. i would recomend you talk to some other installers in ur area. some one who sprays both oc and cc. they will more than likely answer ur questions HONESTLY and help you select a foam that is right for ur application. not just push thier product and bad mouth all others. wich, by the way, is basicaly the same stuff they are selling. good luck.
Gerry Wagoner Posted: Aug 09, 2007 08:15 PM	As a 24-year veteran, I agree completely with ol' Trout. Check with a few other spray-foam contractors in the area for open-cell quotes. I personally prefer open cell on unvented attics for the precise reason you mentioned (it covers the top chord of the truss [or joist]). Best wishes/ olger
Scott Plantier Posted: Aug 10, 2007 09:23 AM	Hi, Thank you for the prompt replies! Actually there was not any putdowns here of other's foam by 6 installers of various brands but one Demilec installer saying Icynene was cleared for only 4" or so for a MA. attic..... of course he'd quoted 8800 for 8 + of 1/2# over 2172 s.f. What I've read is you have 95% of the gain in 5", going to 8 is VERY costly for only 2-3% gain. Today I'll be meeting with one last pour installer who uses an infrared camera throughout the process of pouring Sealection 500. Sounded very thorough and I'm really interested in the walk thorugh of the place. BTW it has 2" cavities on the plank first floor-the entire wall system is lap siding on 1 1/2 x 12 vertical planks faced with building paper on both sides, a 2" void, another layer of paper then the horsehair plaster and lath. Has anyone foamed something similar in the cold areas (7400 degree days) like Western MA? Thanks again, Scott

Author

Comments

Scott Plantier

Posted: Aug 09, 2007 10:29 AM

RetroFoam wall and OC closed attic

Hi,

I'm a carpenter redoing an old plank /framed home. 2" and 3"cavities for the plank and I'm considering Retrofoam to retain interior finishes (horsehair plaster and lath.) Retrofoam is R4.6 with:
Perms Per Inch of 6.631
Permeability 270C/50% UR µ=3.36
Surface Absorption <1% by vol.
ASTM E96 PM/MAT

I have lap siding over 2" planks a 2 or 3" void then plaster and either wall paper or a primed and latex top coated finish. The attic is planned for 6+ of Icynene with all framing members wrapped to eliminate thermal voids. (an OC the forum is familiar with)

Where's everyone stand on this and what is the situation of suits for these closed attic spray jobs? Am I headed the wrong way all together?

philip mullins

Posted: Aug 09, 2007 07:35 PM

i personaly would recomend closed cell (rigid) foam, especialy in an unvented attic system. but open cell is still leaps and bounds better than fiberglass. though it does not stregthen or seal nearly as well as cc. since you mentioned the foam company you have chosen i can only guess that you have been told that cc will crack, and that all other products available are junk and thiers is great. the truth is that all oc foams are very similiar and the biggest factor in performance is in the quality of the installation.

sounds to me like you are doing a top notch restoration. and you are doing rite to research a little before moving ahead. i would recomend you talk to some other installers in ur area. some one who sprays both oc and cc. they will more than likely answer ur questions HONESTLY and help you select a foam that is right for ur application. not just push thier product and bad mouth all others. wich, by the way, is basicaly the same stuff they are selling. good luck.

Gerry Wagoner

Posted: Aug 09, 2007 08:15 PM

As a 24-year veteran, I agree completely with ol' Trout.

Check with a few other spray-foam contractors in the area for open-cell quotes. I personally prefer open cell on unvented attics for the precise reason you mentioned (it covers the top chord of the truss [or joist]).

Best wishes/

olger

Scott Plantier

Posted: Aug 10, 2007 09:23 AM

Hi,

Thank you for the prompt replies! Actually there was not any putdowns here of other's foam by 6 installers of various brands but one Demilec installer saying Icynene was cleared for only 4" or so for a MA. attic..... of course he'd quoted 8800 for 8 + of 1/2# over 2172 s.f. What I've read is you have 95% of the gain in 5", going to 8 is VERY costly for only 2-3% gain. Today I'll be meeting with one last pour installer who uses an infrared camera throughout the process of pouring Sealection 500. Sounded very thorough and I'm really interested in the walk thorugh of the place.

BTW it has 2" cavities on the plank first floor-the entire wall system is lap siding on 1 1/2 x 12 vertical planks faced with building paper on both sides, a 2" void, another layer of paper then the horsehair plaster and lath. Has anyone foamed something similar in the cold areas (7400 degree days) like Western MA?

Thanks again,
Scott

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