Rigid Insulation Over Tpo Roof
The roof deck can be plywood metal concrete or wood planks.
Rigid insulation over tpo roof. Rigid foam insulation installation prepare roof deck. The energy argument is argumentative. The iso is covered with 60mm tpo. The rigid insulation over roof would have controlled the temperature of the condensing surface the underside of the roof deck so that i would not have had to use the spray foam except at the perimeter to provide the air seal to the tops of the walls.
A roof over a vented unconditioned attic does not need to include any insulation. I am trying to figure out the best insulation build up under this roof situation. Insulation cover boards training and education take advantage of industry leading training and education though care the center for the advancement of roofing excellence. Insulation board should be added between the old and new roof systems to ensure proper insulation and to reflect heat from the outside.
3 5 in the middle. About half of our indiana projects specify a vapor barrier under the roof insulation. There is 1 4 of iso at the edges built up to approx. The first step with roof installation is to prepare the roof deck by getting rid of all dirt dust and contaminants.
There is polyiso over the plywood built up 1 4 12 on all four side to the the center. With this kind of roof the insulation follows the slope of the roof. The vapor barrier protects the roof insulation from the vapor included in the interior air. This sandwich will cost a bit more in short term but it s much cheaper than tearing off new deck to fix leaks.
Best to use 2 part adhesive foam to attach insulation to roof substrate and then glue tpo over iso this way there are not screws under tpo minimizing punctures from underneath. Payback is not the way to do it at least not in my. The bottom layer of a single ply membrane roofing system is the roof deck or substrate. Coated fiberglass facer ideal for fully adhered systems provides a broader compatibility and higher performance with.
However most cathedral ceilings and low slope flat roofs are insulated roof assemblies. Available in both foam and rigid form choose the board type. There s a reason polyiso rigid foam insulation is used in more than 70 of commercial roof construction as well as in many residential builds. The plywood.
Achieves fm vsh approval with adhered 60 or 80 mil smooth back jm tpo membrane and standard jm tpo membrane adhesives when 4 x4 panels are adhered in low rise foam adhesive ribbons 12 o c. There is no ice water or vapor barrier under the iso. This vapor if left unchecked can wet the insulation and over time will reduce the r value of the insulation and lead to mold. Meets the requirements of astm c 1177.