Causes of Roof Membrane Slippages

About Roof Membranes

• Roof membranes are made from durable, generally waterproof materials that help to keep moisture off building materials and interiors. Membranes may be built up in several layers, or may be a single-ply layer of material. Roof membranes may be felt, polyester, fiberglass, or a polymer such as bituminous hydrocarbon or synthetic rubber. The top layer of roof membranes may be coated with solar reflective or UV-resistant compounds. Problems can develop, particularly in multi-layered membranes, when the individual layers separate and slip out of position, exposing layers beneath.

What Is Membrane Slippage?

• Slippage can be defined as the relative lateral movement of roofing materials on a built-up membrane system. It usually occurs on roofs that are sloped, and demonstrates as separation of the materials, exposing lower layers or even the base sheet. These layers can then be damaged by exposure to the elements. Slippage can also cause water intrusion into adjacent materials, which can cause extensive damage throughout the roofing system and require replacement of the entire roof.

Common Causes of Roof Membrane Slippage

• Roof membranes can slip out of position from improper application of the bitumen, according to the Facilities Net website. Slippage can also be caused on roofs with 1/2- to 1-inch slope when the felt layers are not properly anchored into position. In modified bitumen-type membranes, slippage can also occur at the lap seams when roofing material is incorrectly applied.

Maintaining Your Roof to Prevent Slippage

• Initial construction methods and materials should be carefully inspected and controlled to avoid problems with membrane splitting and slippage. Walking on roofs can cause damage to materials that can lead to slippage of the membranes. Periodic cleaning of the roofing material with compounds recommended by the manufacturer will help to preserve the membranes. Avoid extreme high-pressure cleaning because it can damage the membrane materials. Periodically inspect roofing membranes after the winter months to determine if any damage has occurred and repair small problems before they become larger, more expensive issues. Consult with a roofing contractor if extensive membrane separations are found.