Spray Foam Over Attic Floor
Climate Zone 6A – A friend with a tight budget is getting new roof sheathing and shingles due to hail damage. The home is 60+ years old, drafty, with minimal attic insulation. They have attic trusses, so there is a kneewall-to-cathedral-to-small overhead attic condition.
8-12″ of continuous exterior insulation (they would only do EPS) is likely out of their budget.
Would it be disastrously ill-advised for them to just do 4″ of HFO closed-cell spray foam the backside of their ceiling/walls during the short time that all their roof decking is removed?
I understand its not an idea R-value…but seems like it would be a substantial improvement for vapor, air leakage and R-value for what they have and not risk long term mold/moisture issues like just packing batts in would.
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