Vapor Diffusion Port Ep. 2 #AtticRetrofit

One of my favorite applications because it allows for sealed attics sans spray-foam, by allowing vapor created by inhabitants with a building to rise up & escape out the roof ridges.

[madpitcher]

Extremely helpful and concise explanation on a very important detail. He’s trained with the master and it shows. 🙏

[FLT]

This is exactly what we did on our house, except we have a shingle roof. We haven't enclosed the interior yet though.

[zhugeliang]

matt risinger cut diffusion ports near the ridge but not on top. I think it's smarter because on a slope the vapor control membrane is less likely to sag and accumulate water. however I didn't get his design fully because the ports were not cut all the way through the sheething there was wood behind blocking them, and he didn't bother to explain in detail. alright thanks for reading.

[zachcoppinger]

Do you still fully insulate the attic up to the ridge? Or do you leave a gap in the insulation as well at the ridge? If you are using insulation on top of your roof decking, are you running that all the way up to the top of the ridge covering your diffusion port? Or are you cutting the insulation short equal to the cut out of the port and keeping an open path for the moisture to escape?

[ClassicRoof]

A year or so later, does the vapor diffusion port seem to be working?

[mikem]

Do you need a vapor diffusion port with roof deck open cell spray foam if you put dehumidifiers / hvac supply and return in attic?

[iowac]

Can you do this after roof installed? Like just got roof installed we have ridgecap and im looking to finish out my upstairs and windering if it better to change over to non vented so we can install insulation like rockwool up against the roof deck.

[GenZyannd]

up there with no restraint 😅 looks scary