WDR Roofing Company Austin - Roof Repair & Replacement
Austin, TX, USA
In addition to asking you readers for an evaluation of my plan, I have An additional query introduced about by fears expressed by an area builder. He is worried that after the AC ducts are inside the conditioned Place that the ducts might be at risk of sweat and can drip throughout my furnishings.
As Monthly bill Rose notes, air tightness of your assembly, the two inside and out, is of important importance - we need to prevent the air move. For that reason I'd suggest an assembly that utilizes materials intended to deliver air tightness even though also maximizing the drying potential in the roof assembly. The depth illustration I have attached shows such an tactic. Solitex Mento 1000 membrane is applied on the skin of your insulation - a vapor open up, nonetheless h2o and air-tight product - with vented cavity earlier mentioned - allowing for for max drying out and preventing any wind/air penetration from the insulation.
As with every type of vent baffles, it’s a smart idea to concentrate to airtight construction techniques, especially if you'll be installing air-permeable insulation in the rafter bays. Seal the edges of each panel with caulk, and tape the seams between panels with a high-quality tape. (In case you are putting in air-permeable insulation like fiberglass, mineral wool, or cellulose, the ventilation baffle isn’t optional; it’s required.
Many thanks to the confirmation and advice. Considering the fact that every thing is dry this time of year and the home was lately tented for termites, I will insulate through the beam and seal up the apparent air entryways. At the time I'm able to see inside of I feel I am going to have a much better notion exactly how much moisture has long been in there through the years.
If you'd like to develop an unvented insulated roof assembly, you may have two alternatives: (a) You may increase rigid foam to the outside facet of your roof sheathing, followed by a 2nd layer of roof sheathing and new roofing, or (b) You can insulate the underside of one's roof sheathing with spray polyurethane foam.
The key flaw With this roof seems to be to generally be the ice and h2o membrane at the highest position during the rafter bays. Would just typical felt paper have authorized more than enough moisture to dissipate in the roof sheathing averting rot?, I sort of doubt it.
As building scientist Bill Rose has revealed, code click requirements for Visit Website roof venting had been by no means dependant on investigate or scientific rules. In a very nicely documented JLC
In order to make an unvented insulated roof assembly, you most likely don't want to disturb the tile roofing. That signifies that essentially the most proper insulation will be spray polyurethane foam. Needless to say, the existing insulation need to be taken off in advance of you put in the spray foam.
[Editor's Take note: Bill Rose just despatched me the subsequent feedback in an e-mail; he provided his permission to put up the opinions.]
2. Set up strong website-constructed air flow baffles in Every rafter bay before you spray the foam. That way you find yourself with a vented cathedral ceiling.
A. As I wrote while in the posting, "Most rafters aren’t deep sufficient to support the insulation visit this page necessary to meet minimum amount R-values necessary by code, particularly if the rafter bays include a air flow channel. ...
Again to your vent notion. I actually Assume venting a roof that is airsealed in the inside effectively and crafted without vent chutes is quite possibly the best way to create cathedral ceilings.
Many thanks for locating the thread previously mentioned...Take note that in submit #seventeen, Robert Riversong talks about the "vented over roof". I agree with you that this process justifies some awareness for cathedral ceilings.
I am guessing that neither of those specifics just matches your needs. But as I pointed out before, In order for you a customized element, you most likely need to hire an architect or an engineer. Very good luck.