I’m not big on spray foam and needed a comparable option for attic conversion and flat roof. Check this much cheaper and diy friendly solution I landed with.
kept me up at night when I was about to pull the trigger on a spray foam install, I actually just had a issue with my chimney and everything worked as planned, was able to identify a leak.
I'm currently installing the Sika RMAX 2 in boards and tried all kinds of diff approaches to cutting it with little mess , even tried the Bullet Tools Centerfire FoamBlade CC52-1507 7.25 but found that a sturdy razor works best Most important thing to note when using a utility knife, have a fresh blade and do multiple passes until you fully cut through, it's super quick and very little dust ; my favor blade so far is OLFA LA-X 18mm Utility Knife
sweet, yeah that long blade is probably great, and you wouldn’t have to snap the product so it’s all probably coming out nice. I just already had that insulation knife around and once I realized it worked pretty good I never looked back.. the very long blade of the insulation knife also allows me to use it as reference and get a very nice straight cut.
I use the Bosch foam jigsaw blade to cut this kinda stuff, it works out great. Also how are you addressing the thermal bridging on the rafters that aren’t covered in insulation?
A forth layer across the face of all the rafters would have been ideal, but it would have left unwanted air gaps in between. Also at the end of the day it’s an added cost, going to be a rental unit, and consumed more precious head room.
Fantastic question, I spoke with several local roofers and they all said it’s a perfectly fine installation as long as it’s a similar installation to spray foam, no ridge and Eve vents. They also had no concern of the shingles experiencing higher temps and all said the temp really wouldn’t be all that different with a vented assembly and doesn’t affect warranty of shingles.
