spray foam or cold roof retrofit
I met with a client today (Roch., NY) who had severe ice issues. He needs a complete tear-off (2 layers w/ shakes). There are a number of dormers that are all stucco, (ugghh..). I am thinking of trying to sell it one of two ways depending on how the actual costs and final result of R-value compares. Original thought was a cold roof similar in design to the article in 11/08 JLC. The stucco repairs alone would jack the number way up without geeting an optimal R-value. The int. vaulted ceilings are all plaster and lath. My next thought was closed cell spray foam but apply it to the stucco before the sheeting goes on. My question is, is this a dumb idea? I read an earlier post today about Soy… something or another that I could apply myself as I sheet.
Not to sure and I have some homework to do. Just thought I’d throw it out there.
Not an insul. expert,
Dustin
Replies
I don't understand what you're proposing. Describe it more carefully.
Solar & Super-Insulated Healthy Homes
The homeowner needs a roof tear-off anyway, the roof is shot. It is a 1920's cape, with many dormers. I was thinking of stripping the roof, clean out all the rafter cavities and spraying them with foam as I sheet the roof. The cold roof option seems to be more work than the payoff in R-value. I just haven't seen it done this way and wasn't sure if spraying the plaster was OK vs. spraying the sheeting from the inside.
I'll do more research after x-mas is done.
Thanks in advance,
Dustin
A cold roof won't give you any more R-value - it will give you less since part of the rafter cavity will be uninsulated.
There's no inherent reason the roof cannot be foamed from the top, but I would advise against DIY options. The mix and method is too important. If you can get a foam installer to climb the roof, that would be the way to go.
However, whether the roof is vented or not, leave an inch or so of air space above the foam so that the roof sheathing can dry if it ever gets wet. This makes more of a difference in cathedral roofs than venting.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
I'm considering the Soythane product. I know thet you are very educated in this arena so I am not doubting you. I think after a few test sprays I will be able to learn the gun. I'm not going to make my client a test gerbil, that's why I'm asking questions. Can I spray it in there?, "Yes". Is that the best solution?, "That's why I'm picking your brain"
Thanks
Dustin
All things considered, that sounds like a great way to deal with this.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I think so, but it seems like an out of the box idea and never having heard of it being approached this way before I was skeptical that maybe I'm missing something.
Thanks,
Dustin
I just re-read my initial post. I didn't mean "Apply foam to the stucco", I meant to the plaster on the underside of the rafter.
thanks,
Dustin