Signs of an Aging Flat Roof

By Dymon Brady

A few weeks ago, we talked about estimating the expected life of a pitched roof.    Watching for signs of wear and tear is much different when you are talking about a flat roof vs. a pitched.  In fact,  a membrane roof will wear out much differently than a tar and gravel roof will.   These different signs are important to understand and be aware of.

PVC

PVC membrane typically lasts for about 10-25 years depending on the brand and thickness of membrane.  When PVC begins to age you may see some of the following signs:

• It can become brittle

• It has formed cracks

• It has begun to pull at the edges of the membrane.

If you have ever seen an old, brittle PVC pipe, you will know what to look for.  PVC membrane will age identically to the PVC in the pipes.TPO

TPO membrane usually lasts from 15 to 25 years (keep in mind TPO has only been a roofing product for about 23 years), depending on the system and skill of installers.  Some brands of TPO come with a lifetime warranty when a 60 ml thick membrane is installed on a residential building.  When looking for indicators that your TPO roof is aging, look for:

• Worn areas on the roof.  TPO will simply wear thin in certain areas as it reaches the end of its functional life.

• The membrane edges.  Older systems will infrequently pull from the edges as other flat roofing membranes do.  New methods of installation now help prevent TPO from pulling away from the perimeter.

The seams should not separate in TPO as it is a Thermoplastic roof and the seams are fused together (rather than glued or taped).

EPDM

EPDM membrane itself lasts a very long time with an expected life of up to 40 years with some types and thicknesses.  However, in Utah’s abusive cold weather climate, the seams curl and separate after about 10 to 20 years.  You will find similar issues to TPO with EPDM as it ages:

• Thinning throughout the membrane and pulling from the edges of the roof.

• Bridging. Many times the roof fails due to extensive “bridging” or “tenting” where the membrane on the roof turns up a wall, skylight curb, HVAC curb, pipe, etc.

One last thing to look for in EPDM is whether the EPDM has a reinforcement fabric or scrim in the sheet.  If it does, you will be able to see the pattern of the scrim when looking closely at the membrane.  Reinforced EPDM will bridge less than unreinforced.  The non-reinforced EPDM will split in the field of the membrane and will be susceptible to tearing as it shrinks at a faster rate.

It is important to note that the most important factor in your roof’s longevity is the workmanship in how it was installed.  If the roof is not installed properly, it doesn’t matter how thick the membrane is.  You don’t want to have to replace your roof after only a few short years simply because the installers did not do their job the way it needed to be done. The level of workmanship in the application of a system can be determined with a trained eye.  As with any roofing concerns, a simple answer is to contact a roofing contractor to come in and inspect your roof for you.  Brady Roofing will do these inspections and estimates for free!  Call today to schedule a free estimate or to discuss any questions concerning your roof.