Flat Roof Construction Layers

All three types of flat roofing cost 250 to 350 per square 100 square feet but prices vary according to region and size of the roof.

Flat roof construction layers.

Four plies denotes a four layer flat roof membrane system. Since 2005 if you replace 25 or more of your roof covering felt then you need to ensure that the entire flat roof has enough insulation to satisfy current building regulations. Asphalt shingles typically can have one more layer added over the top two roofs total. Roof covering typically of flat and rectangular shapes and made of various materials such as slate wood flagstone plastic metal and composite materials.

For many years it was acceptable to put even the third layer. There are several methods and materials for the design of the exterior surface of a warm or cold flat roof. Known technically as elastomeric or plastomeric roof membrane depending on the material single ply roofs come in a few different varieties including. For that reason cold flat roof construction needs to keep in mind the need for unblocked airflow.

The number of plies on a roof implies the number of layers i e. Hot tar and gravel. This can include epdm rubber and fibreglass talked about above but commonly especially in the trade and in this article it refers to pvc tpo tpe and pib. This could mean flat roofs may not raise the same red flags they used to.

This only applies to flat roofs over habitable parts of your home so it excludes garages sheds some porches and most door canopies. The felts are reinforced with either glass fiber mats or organic mats ply sheets and when joined with the bitumen form a durable roofing membrane. It is a waterproofing layer made of regular felt stacked above the solid decking board and then completely covered by the shingles or other roofing materials. The 3 most common materials used for flat roof construction.

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. Flat roofs are hard to replace. Pvc single ply membrane arguably the most popular of all flat roofing materials some contractors even install only pvc membranes for higher end residential installations pvc membranes are a single layer of thermoplastic material. But now flat roofs often are constructed with fewer layers because of improved waterproofing technology.

On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing. Built up roof bur the traditional hot tar and gravel. In short any roof covering that can make a flat roof waterproof in one layer unlike roofing felt with its 3 layer system for instance. Steep sloped roof products such as tile slate metal and shakes only allow one layer.