Flat Roof Assembly Detail

Flat roofs are hard to replace.

Flat roof assembly detail.

But now flat roofs often are constructed with fewer layers because of improved waterproofing technology. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. Test roofing membranes for integrity prior to covering from below. Heat welded seams provide superior strength.

This could mean flat roofs may not raise the same red flags they used to. In unvented flat or low slope roofs with parapets perform a full flood test to ensure leak free installation of roofing membrane. Today s variety of flat or low slope commercial roofing options roof pitches ranging from 12 to 3 12 is no longer simple and has grown considerably in the last 50 years. Cad details document name pdf dwg download all cad construction details 37 1 mb 3 4 mb mc01 identification of roof areas 694 kb 167 kb mc01a single layer underlayment 678 kb 302 kb mc01b double layer underlayment 711 kb 322 kb mc02 vent pipe flashing 626 kb 349 kb mc03 valley.

Short for thermoplastic polyolefin tpo is a single ply roofing membrane that offers excellent performance at a cost effective price. This is how to detail an unvented roof assembly for flat and low slope roofs. The roof membrane is fully adhered to a coverboard that is mechanically attached to the structural deck in the field of the roof and an allowance for membrane movement is provided at the perimeter of the roof assembly. The perimeter of the roof assembly insulation is wrapped to prevent interstitial airflow from the parapet into the multilayered.

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. Some observers suggest it s harder to replace a flat roof than a traditional pitched shingle roof because of the labor required to remove its layers especially on older flat roofs. Before constructing a flat roof assembly please refer to the unvented roof assembly comments under 6 2 vented and unvented roof assemblies and if applicable 6 3 parapet walls. Just enough slope to drain water but also flat enough to be a problem if not constructed properly.

Roof assemblies must control for exterior moisture in a monolithic and complete fashion. Tpo s long term heat uv and natural fungal resistance plus flexibility without need for plasticizers also make tpo a reliable low slope roofing system. Of course flat roofs are not flat but have a very slight roof pitch of between 1 4 to 1 2 per foot.