Developer · Closter, NJ · Member since 2016 · 392 posts · 109 votes
A friend of mine is doing an small addition in Saddle Brook,NJ they need to either get access to spray foam insulation or find an alternative to R49 insulation. Code is R49 or spray foam, but they only have roughly 9.5 inches of room to work with. but, R49 is about 14 inches thick. Any idea??
Thank you for all your input !
Contractor · Fort Worth, TX · Member since 2015 · 379 posts · 740 votes
9y
Not sure I understand the question. "Get access to spray foam"? You can buy kits to do it yourself - Google "spray foam kit" - but they're going to be relatively expensive per board foot. There should be contractors in your area that do it - they'll spend $40K and up on a professional truck-mounted rig.
In my area, they typically charge around $1.20/board foot. You're in a blue state, so I assume a contractor has to have 187 different licenses to spray some foam in a house, and cost is probably higher. But it's still likely to be best to hire a contractor than try to DIY it without proper equipment.
Haverford, PA · Member since 2017 · 9 posts · 1 vote
9y
Is this a roof or a floor? In either case you may be able to add a 2x4 or a 2x6 to the bottom of said rafter/floor joist turning your 9.5 in into 13" or 15" respectively. Are you sure about r49 being the code? I'm in PA and we have used this method to get to r38, but we've never been asked to get r49. If you can't add any lumber to the bottom you might be stuck with spray foam alright. Hope this helps.