Insulation Above Flat Roof Detail

Inverted roofs are a type of warm flat roof where the insulation is above the waterproofing layer.

Insulation above flat roof detail.

Flat roof detail masonry cavity wall flat roof insulation above and between joists. 3 screw in 1 3 of iso insulation over roof substate and then install plywood over iso boars same as 1 but more work. Flat roof detail masonry cavity wall flat roof insulation above and between joists. Gable end detail overhang cut and then rebuilt to hide the thickness of the over roofing rigid insulation.

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. An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot. The following images provide examples of flat roof details. Roof edge detail overhang extended to hide the thickness of the over roofing rigid insulation.

This means that the insulation should be highly resistant to water absorption for example an extruded polystyrene based product which will not be affected by water or repeated freeze thaw cycles. A note to consider before construction. Flat roof insulation installation the rigid foam board insulation we used was 2 thick and came in 4 x 8 sheets. Installed a new fully adhered membrane to the top of the old board sheathing prior to adding all that rigid insulation.

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. Alternatively battens can be secured to the underside of the. Consider geography budget and use for the roof to determine the best option. 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.

If insulation is installed below the flat roof deck this is called a cold roof. Parapet detail masonry cavity wall flat roof with parapet insulation. Flat roof detail examples. From there the flat roof system you choose will determine the materials you apply.

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.