5 Reasons For Wrinkling On A Flat Roof

Posted on: 21 December 2021

The membrane that protects your flat roof from leaks should lie flat and secure. If it develops wrinkles or bubbles, there is a problem that needs to be repaired quickly before leaks occur.

1. Insulation Shrinkage

A common cause of wrinkling on a flat roof membrane is actually the result of insulation issues below the roof membrane. Some insulation products aren't temperature stable, which means they may shrink or expand when exposed to hot or cold. This movement then leads to wrinkling on the roof membrane, because the membrane is adhered to the insulation panels. Upgrading to better insulation and re-installing the membrane is necessary.  

2. Poor Tightening

During installation, a flat roof membrane is pulled taut before it is fastened in place. If there is a failure to fully pull the membrane taut, then it can loosen and begin to wrinkle over time. This can sometimes be repaired if caught early, before the membrane begins to crack or crease along the wrinkles. Your roofer will tighten up the membrane before re-attaching it in place. 

3. Failed Adhesion

Most flat membranes are held in place with some sort of adhesive. Some are contact adhesives while others are thermoset types that require heat to fully adhere. If the adhesive isn't properly applied or if it doesn't fully adhere, the membrane may move and develop wrinkles. When caught early, new adhesive can be applied and the membrane can be properly attached in place. Otherwise, you may need to fully replace the membrane if it has warped or cracked due to wrinkling. 

4. Wind Damage

When the wind hits a roof just right, it can get underneath a poorly adhered membrane and cause uplift. Once the wind dies down, the membrane may settle back into place, but now it will be stretched and wrinkled. If there is no other damage, the membrane can be smooth and properly attached so that uplift and wrinkles are no longer a concern. Uplift damaged membranes will require replacement, though. 

5. Trapped Moisture

Although not technically wrinkles, blisters resemble wrinkles and are a common issue on flat membrane roofs. These blisters, or bubbles on the membrane, are caused when moisture penetrates beneath the membrane and causes pockets of adhesive failure. Their presence indicates a leak or condensation issue with the roof, which must be addressed before the bubbles can be removed. 

Contact a commercial roofing company, such as Roofing Solutions Company, if you notice any wrinkling on your building's flat roof membrane.