Insulation Above Flat Roof Detail

Roof edge detail overhang extended to hide the thickness of the over roofing rigid insulation.

Insulation above flat roof detail.

Consider geography budget and use for the roof to determine the best option. Gable end detail overhang cut and then rebuilt to hide the thickness of the over roofing rigid insulation. Installed a new fully adhered membrane to the top of the old board sheathing prior to adding all that rigid insulation. Flat roof detail masonry cavity wall flat roof insulation above and between joists.

The following images provide examples of flat roof details. A note to consider before construction. Then you should use gaf deckarmor which is by far the best synthetic roof underlayment at reasonable price about 0 22 sq ft. Flat roof detail examples.

Once the roof demo was complete and the flat roof was cleared of any remaining debris some rotted 2x material around the perimeter of the roof was replaced. An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot. Owens corning insulation products help improve thermal performance and control moisture in commercial institutional and. Foamular xps roof insulation for commercial buildings page 5 foamular xps roof insulation for commercial buildings foamular xps insulation is a rigid foam insulation which meets the needs of today s design professionals for a truly sustainable insulation product.

As for insulating below the joists an insulating laminate insulation bonded to plasterboard such as celotex pl4000 or a separate rigid pir insulation board finished with a separate sheet of plasterboard can be securely fixed to the joists to provide an internal finish to the roof. From there the flat roof system you choose will determine the materials you apply. 3 screw in 1 3 of iso insulation over roof substate and then install plywood over iso boars same as 1 but more work. Saint gobain insulation uk manufacture and supply glass mineral wool slabs and rolls along with rigid polyisocyanurate pir boards that can be considered suitable for a wide range of applications across flat roofs whether you re looking to insulate at joist level or above the roof deck in your flat roof construction.

If insulation is installed below the flat roof deck this is called a cold roof. Alternatively battens can be secured to the underside of the. Inverted roofs are a type of warm flat roof where the insulation is above the waterproofing layer. Flat roof insulation installation the rigid foam board insulation we used was 2 thick and came in 4 x 8 sheets.

Air permeable insulation such as fiberglass batts dense packed cellulose or blown in fiberglass can t be used alone for an unvented assembly since these types of insulation can allow moist indoor air to reach the cold roof sheathing leading to condensation or moisture accumulation.