Single Ply Membrane Roof Minimum Fall

Our technical department can design bespoke insulation schemes for individual projects and provide advice on roof fall design.

Single ply membrane roof minimum fall.

Good practice guidance recommends that flat roofs defined as 10º should not be completely flat and should be designed with adequate finished falls to ensure the completed roof drains freely. The recommended minimum fall for a flat roof is 1 80 0 72. However both the british standards and sig advise falls of 1 40 to take account of constructional inaccuracies potential roof deflection and different types of roofing material. This applies whether the waterproofing is a polymeric single ply membrane a reinforced bitumen membrane or another type listed in bs 6229 2018 the code of practice for flat roofs with continuously supported flexible waterproof coverings.

The cost associated with the material and installation can vary widely depending on roof conditions the attachment used and the type of membrane being installed. It is accepted good practice to design in a fall or slight gradient of at least 1 60 which equates to 17mm over 1m. Our membranes are manufactured in our state of the art production facility in chesterfield which has bs en iso 9001 bs en iso 14001 and bes 6001 accreditations. As the only uk manufacturers of single ply membranes we offer a full range of single ply roofing systems incorporating all the components required to deliver complete high performance flat roof solutions.

We also cover spray applied foam and liquid roofing options. Single ply roofing cost. Single ply roofing is priced per square foot and an average price for materials and installation of a 60 mil roof may range from 3 to 5 per square foot. Common flat roof membranes discussed in this article include built up asphalt tar and gravel modified bitumen and single ply membranes like epdm pvc tpo and kee.

Bs6229 states that the minimum finished fall of single ply membranes at any point should be 1 80. It is recommended never to design a roof that is completely flat. Ponding water will not have any detrimental affect on the monarplan pvc single ply roofing membrane however it is recommended that roofs be designed with falls minimum 1 80 to remove water from the roof. Sika sarnafil watchmead welwyn garden city al7 1bq 01707 394 444.

Tapered insulation systems are a lightweight convenient and cost effective alternative method of providing falls to the roof and can be used with our reinforced bitumen membrane rbm and synthetic single ply roof systems.