Installing the foam from the outside is better because in your case you have a finished room inside and i assume you do not want to gut/renovate the house. That being said, when it comes to installing the foam and coordinating with the roofer and the weather (rain, temperature and wind), this option becomes a bigger headache and costs more money to do. This application should not cause moisture issues when done correctly. Once a house does become very tight (air sealed) it's recommend to have an HRV installed to your HVAC system or do periodical air exchanges by opening up a window from time to time.phantomvs wrote: ↑Feb 13th, 2019 3:18 pmNot sure if this has been asked.
I have a type of mansard roof/ siding on my 1974 home. This is for the siding only, roof is flat, with no attic.
I plan on changing shingles on side of home, now if i remove shingles and plywood can i use spray foam there on exterior wall to boost up r-value ?
Then reinstall plywood and shingles. Or is it better to insulate from the inside, just way easier on outside when renovating the roof.
Keeping inside intact not disturbing drywall.
Or will it cause moisture issues ?