Q. "If I execute the unvented roof as built and set 4 inches of polysio within the roof deck, am i able to then use open-mobile foam amongst the rafters?"
In case you go in advance with the plan, you should include things like a smart vapor retarder on the inside side with the assembly, to attenuate the transportation of humidity from the interior towards the sheathing.
I have a number of queries that incorporate lots of the topics that you have coated in these articles or blog posts, but I am trying to implement them in the retrofit scenario. We're focusing on upgrading the energy performance, together with extra/updating insulation, for our Practically a hundred yr aged 2-1/two story balloon frame home (stucco more than lathe exterior).
A. As I wrote in the post, "Most rafters aren’t deep ample to support the insulation required to meet minimal R-values expected by code, especially if the rafter bays incorporate a air flow channel. ...
The precise design and style revealed was for a Passive Home. The roof thickness & usage of a assistance cavity may well look like overkill for many tasks, but If you prefer an airtight lid, a company cavity will get you there - forever... And allow you to wire and light the interior.
I'm making an attempt to choose on the roof venting tactic for my subsequent project; a story and half cape with twelve" double 2x4 partitions with dense pack cellulose for R-40, and 2x10 rafters designed down from within like a Larsen Truss to eighteen" depth to Roofers in Huntsville TX accomplish R-sixty, also dense packed cellulose. On the interior, I would like to use Intello for vertical partitions and taped cdx on sloped ceilings.
Q. "If I install a polyethlene sheet concerning the bottom of the batting plus the sheetrock [It might be hooked up into the purlins], wouldn't this be an interior vapor barrier?"
We have already been just lately setting up plenty of closed mobile foam straight to the roof sheathing with terrific outcomes. Nevertheless I ponder When you have listened to about what happens in the event the inescapable roof leak happens?
My guidance could well be to seal the present vents. If insulation contractors in your town are setting up 3 to 4 inches of shut-mobile spray foam above the roof sheathing, you don't need to stress about condensation or dampness accumulation as part of your sheathing.
one. Your recommendation is simply a slight variation with a element that is definitely currently discussed in my blog, namely cellulose put in with a vent channel among the top with the cellulose and the roof sheathing.
Q. "For an unvented construction without any insulation earlier mentioned the sheathing, how about using Wooden fibreboard amongst the rafters specifically beneath and in contact with the sheathing?"
Another way to incorporate R-price in your roof assembly is to include one or two levels of rigid foam from the roof assembly — possibly previously mentioned the roof sheathing or underneath the rafters.
I wish to appropriately insulate my cathedral ceilings and was wondering to spray two inches of shut cell foam to sheathing, then fill with dense packed cellulose. I am thinking if I am able to connect craft paper and pine paneling to the 2x8 rafters then fill the bays with cellulose.
Can we (does the code allow it)? Will it check this make practical perception? Are there pitfalls because of our local climate? How may We've to modify that to suit it to out predicament?