Reasons Why Some Commercial Roof Membranes Fail at the Seams

Most, if not all, commercial roofing systems are built with durability and dependability in mind. However, that doesn’t mean that they’re completely infallible. One of the most common problem areas when it comes to commercial roofing is the seams. While the seam sealing method will vary depending on the type of commercial roof you have, many roofing issues will often start at the seams regardless.

Commercial Roof Membranes Fail

How Are Seams Sealed?

As mentioned before, the sealing method for seams on your commercial roof will vary depending on your roofing material. Thermoplastic membranes (PVC, TPO, KEE) are sealed by heating the membrane with hot air, causing it to melt and fuse to the next section. EPDM rubber is sealed with adhesives or sealant tapes. Modified bitumen roofs, on the other hand, are sealed by mopping hot asphalt onto the surface or by applying cold adhesive to the seam.

Why Do Seams Fail?

Normal exposure to the weather will eventually cause some seams to fail. UV rays, rain, snow and everything else in between will slowly eat away at your roof, causing the membrane to deteriorate. This is completely normal and expected. However, improper insulation and poor installation techniques can greatly expedite this process. Insulation needs to be secured to the roof; otherwise, it will warp and create lumps under the membrane causing them to pull on the seams. 

If the seams are improperly sealed by the installer, you’re basically inviting moisture to seep into your roof. Remember that just because the membrane seams overlap does not necessarily mean that they are sealed. If you suspect seam failure, contact your roofing contractor right away.

State Roofing & Exteriors is not just a trusted residential roofing expert – we can also handle all your commercial roofing needs. If you want a commercial roof that can resist even the harshest weather, give us a call at (360) 794-7164 or fill out our contact form to set up a free consultation.

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