Your prepare will perform wonderful, given that the layer of rigid foam on top of your roof sheathing has an R-value of a minimum of R-20. For anyone who is employing XPS, you would like no less than four inches of froth. In case you are utilizing polyisocyanurate, you may need at least three inches of foam.
OK, I had been figuring that the entire with the rigid foam + cellulose needed to be a particular R-worth in combination and had been thinking of utilizing significantly less rigid foam. I have been reading through about various sorts of cellulose. Given that I am putting in from previously mentioned would anything like stabilized cellulose do the job as it has slightly water included?
Should really I use airtight baffles or not, I do not see a means to have humidity escaping within a assembly with airtight baffles, fiberglass and xps on the inside, whatever the dew place might be inside this assembly And maybe produce condensation that can't evaporate devoid of ventilation.
Ken's detail (#10) does a good work of chilly weather basic safety. It has what we are searching for: Very good airsealing at the interior, fluffy stuff in the center, and excellent drying channels for drinking water vapor at the very best. By altering from the minimal permeability sheeting into a significant permeability membrane (at top rated) with venting over, there is not any more problem for roof rot though simultaneously wind washing is prevented during the bays from the air & h2o tight membrane with taped edges and seams. It seems to me to be an exceedingly long lasting assembly.
I question the condensation is going on against the chilly ridge beam. Fairly, I do think it is likely that condensation is going on on the underside within your ridge shingles or the underside with the asphalt felt underlayment.
Q. "If I execute the unvented roof as designed and set four inches of polysio on the roof deck, am i able to then use open-mobile foam among the rafters?"
I believe you indicate this: Your cathedral ceiling is presently uninsulated. When you find yourself indoors searching up, you may see page your rafters. Over the rafters you'll be able to see a layer of boards. Is usually that accurate?
In 1969, Larry started his profession with the Collinsville Local community University District as being a band director and Instructor of instrumental audio, a situation which he held for 30 many years, although shelling out most weekend evenings actively playing keyboards, trumpet, vibraphone, and flugelhorn for your Bob Bermes Orchestra, a well-liked location dance band.
I are convinced you need to put up a sketch. I can't visualize what you're referring to from the description. In order to set up an HRV inside your attic, why do you must set up a water resistant stucco roof in excess of some sort of EPS box? Just isn't your attic now dry? Most attics have roofs.
You've got a lot of restraints, and people restraints are top you to some convoluted imagining. As opposed to advising you to definitely adopt a series of compromises, I will explain the correct way to handle your roof, regardless of whether the right way is expensive.
Since I have discussed the best way to get it done, I can even Permit you to recognize that Many individuals have performed what you suggest.
I've plenty of partitions to re-insulate, and once the roof is addressed I am going to have rafter bays to insulate, and It might be practical to acquire some Perception into which sort of fiberglass offers you what profit for its Charge.
A. This can be a grey region while in the constructing code. It is really safe to state that no industrial insulation contractor would use that strategy, which many people call "cut and cobble.
It appears if 1 were to employ dense pack cellulose in a vented cathedral ceiling the vent pop over here channel product must be rigid sufficient to resist the pressure.