Insulated cathedral ceilings are a relatively latest phenomenon. The fad for insulated cathedral ceilings (and fantastic rooms) actually took off from the seventies and 1980s, when examples commenced appearing like mushrooms following a warm rain.
The leading flaw On this roof seems being the ice and h2o membrane at the highest position within the rafter bays. Would just common felt paper have allowed enough moisture to dissipate with the roof sheathing preventing rot?, I form of doubt it.
I've a number of issues that integrate most of the subject areas that you've coated in these content articles, but I'm looking to utilize them in a very retrofit condition. We are working on upgrading the energy effectiveness, which includes extra/updating insulation, for our Just about one hundred 12 months outdated 2-one/two Tale balloon frame dwelling (stucco more than lathe exterior).
for an unvented building without insulation above the sheathing, how about working with wood fibreboard between the rafters specifically underneath As well as in connection with the sheathing? All gaps among the boards and also the rafters full of growing foam / sealant. You might then deal with the rafters with rigid foam to carry your insulation up to necessary R amount and lessen the possibility for the rafters and sheathing, and then put in your airtight drywall underneath this.
In the alternative, if we won't do a ventless roof this way, can we reach our total insulation needs by combining the above and under deck R-Values if we top rated all of it with a vented about-roof? Many thanks for your time as well as your information! Dan
Be certain the roof assembly is as near airtight as you may make it. In case you are using fluffy insulation, you may need two air boundaries: a person below the insulation, and one particular above the insulation.
I have a 50 12 months-outdated seasonal cottage in a northern local weather. The simple 6/twelve gable roof is composed of precise 2x6 rafters (24" oc), sheathed with one/two" plywood and protected with asphalt shingles. There isn't a insulation inside the ceiling and I believe minor to no powerful insulation in the 2x4 partitions. In the summertime the warmth obtain inside of makes residing almost unbearable. I suspect that the biggest bang with the buck can be to handle the ceiling insulation challenge very first, but want to manage the inside visual appeal.
If you put in 2x4s (or 2x3s on edge, installed with extended screws) perpendicular for the rafters, you can deal with many of the thermal bridging issue without the really need to increase a layer of rigid foam.
On an unrelated subject matter: The Chilly Climate Housing Investigate Middle has produced a video clip (underneath) displaying one approach to making an insulated cathedral ceiling. The tactic proven during the video clip is especially suitable for builders in climates matter to ice dams.
Code doesn't look to apply since it's grandfathered in. It looks like I must redo the hall ceiling.
You should utilize Ice & H2o Defend being an air barrier If you would like. But when you select to make use of that solution, you will have to remove the asphalt felt so the Ice & Water Shield is usually adhered towards the roof boards.
An additional query is, should really I carry on the exact same insulation assembly outside? The final image reveals a sizable 10' overhang. Really should I vent this exterior portion or seal the underside with the p.t. plywood this post deck With all the closed-mobile insulation?
EnGard insulation is actually a style of fibrous insulation that resembles a fiberglass batt. It uses polyester fibers as opposed to glass fibers. It is unquestionably not
Also, Why don't you zip panels taped and then roxul batts with drywall above that. Roxul is wonderful stuff I are tests For several years in mad techniques trying to see its abilities. I feel that zip panels, taped effectively, with roxul batts will previous assuming that the roof!