What do you mean by "our AC units require fresh air ventilation"? Fresh air doesn't come from the attic. If there's an atmospheric combustion appliance in the attic, such as an 80 AFUE furnace, then you shouldn't be encapsulating the attic anyway. If that's the case, you don't want spray foam on the roofline at all. You can either change out the furnace to a sealed combustion unit or do your insulating and air-sealing at the flat-ceiling level.
We are turning our roof into an unvented roof assembly by raising the roof and blowing in SPF. We are planning to leave the existing vapor barrier down but remove the fiberglass batting and then adding 6" of SPF in all the cavities, to completely seal and insulate the house. Should we have any concerns about doing it "upside down" and not spraying the foam directly to the underside/sheathing of the roof?
How Much Is Spray Foam Roofing
After researching this, Im curious about a method called poor mans sprayfoam where foamboard is cut to size between studs and sprayfoamed around the perimeter. Aside from the labour doing the job yourself, the cost seems comparable, is one better than the other? What about the quality of the canned sprayfoam around the perimeter? When i see sprayfoam done, it is never a full depth of the studs, so you would get 2.5-3 inches in a 3.5" (2x4) wall. Any thoughts?
Spray foam insulation is a great product. Homes insulated with it can be some of the most efficient and comfortable homes built. I've been in plenty of these homes and can tell you that when spray foam is installed properly, they outperform 99% of fiberglass batt-insulated, stick-built homes. (I can also tell you that 73% of all statistics are made up on the spot, so please don't ask for documentation of that statistic.)
As mentioned above elastomeric coatings can be used to fix almost all types of roofs. Examples of common roof types that will work well with elastomeric coatings include; wood, polyurethane foam, single-ply roofing, modified bitumen, metal roofs, concrete and built-up roofing. If you aren't sure your roof type will work well elastomeric coatings, do not hesitate to contact us. Our experts are always willing to help. https://youtube.com/v/ggLAUsiuI_o
Stop making the same repairs using less reliable products that are not EPDM based, are not UV and ozone resistant, and do not have flexibility built into the material (causing them to crack). EPDM rubber will expand and contract with any surface as seasons change, and will not crack as a result of temperature changes. Other products will begin to bubble and crack in less than two years.
Ames® elastomeric waterproof roof coatings are premium coatings that seal out moisture, renew old surfaces and even save energy. We have products specifically formulated for all types of roofs including; Wood, Tar, Metal, Rolled Roofing, EPDM Rubber, Foam and many other surfaces. From flat roof coating to plywood roof coating, Ames’ liquid rubber roof paint coatings form a waterproof seal to preserve and protect your roof. Our white roof coatings reflect sunlight, substantially reducing roof temperatures and helping you save on cooling costs. Ames® products are environmentally friendly, water-based, non-toxic, VOC-free and can be cleaned with water. If you’re looking for how to seal a flat roof, pitched rolled roof, or just about any other kind, our elastomeric waterproof roof coatings can help you get the job done. https://www.youtube.com/attribution_link?a=ggLAUsiuI_o&u=watch?v=XXXXXX&feature=share
It also has a great waterproofing ability that can shield the roof’s membrane from water and moisture damage. You can also count on the liquid roof coating for its outstanding performance for a wide range of applications and uses. This product can be used at tears and seams as well as in sealing air conditioners and venting systems and anywhere else where rubberized coating is needed.