Portland Roofing Services - Pacific West Roofing
Commercial - Flat

4 Common Commercial Roof Problems

Commercial roofs can experience a number of problems over time. It’s important for business owners and facility managers to know what to look for and when to contact a roofing company. The most common problems seen by commercial roofers include:

1. Faulty Flashing and Pitch Pans
Flashing is installed on walls, curbs and around objects protruding from the roof, like pipes and chimneys, to deflect water from seams or joints. Ninety-five percent of roof leaks occur due to faulty flashing. It most oftenfails because of the expansion and contraction that occurs, causing the flashing to tear of break. Also,the top of the flashing is often not terminated properly and this can break loose allowing water to get in.Pitch pans are also used as a seal around pipes coming through a roof. If pitch pans are not properly maintained or are filled with materials that did not seal adequately, water will run down the pipe and into the roof. These are the most common problem for flat roofs today.


2: Blow-offs and Reduced Wind Uplift Resistance

Leaks are not the only issue that can arise from improperly installed flashing. As wind flows over the roof, the pressure directly above the roof’s surface decreases. Simultaneously, internal air pressure increasesdue to air infiltration through cracks and openings. This results in an upward force on the roofing system,which is referred to as wind uplift. Wind uplift resistance can be reduced significantly if seams are not adequately cured on cold-applied modified bitumen roof systems. If the seams are exposed to wind before they are cured, wind uplift can damage the roof membrane. Improper gravel embedment and too few fasteners in the base sheet during application of hot bituminous and torch-applied modified bitumen systems can also have similar consequences. High winds can also blow off the caps on chimneys and vents allowing water to get into the pipe.

3. Standing Water
Standing water is sometimes due to a clogged or blocked drains, but most often it is due to poor roo fdesign or installation. Allowing water to stand on the roof can deteriorate the roof and ultimately cause leaks. During the design of a dead-level roof, slope should be included with tapered insulation or crickets.While installing hot bituminous systems, poor mopping can produce voids in the membrane, block drains, and result in standing water as well as void the warranty. Before repairs are made, it’s important to investigate the source of the water. Sometimes an HVAC unit without a condensate drain line can be the culprit and sometimes they just get clogged if no one is maintaining them. We will always do a thorough inspection before making a repair and check drains to be sure they are free of dirt and debris.

4: Punctures and Additional Penetrations Post-Installation
Every roof system’s performance is compromised when new penetrations and equipment are added,unless proper precautions are taken. Damage from foot traffic can also be detrimental, especially for single-ply or spray polyurethane foam (SPF) roof systems. Construction traffic can cause cuts andscrapes in the membrane and damage the underlying substrate. In addition to causing leaks, this may also void the guarantee. When penetrations are added or removed from a metal roof, there can be catastrophic results. The caulking and sealants used to seal the whole can be ineffective because metal roofs incur a lot of expansion and contraction, and this will result in a number of persistent problems. Ceramic coatings will reduce the solar heat load and reduce expansion and contraction.

We fix these issues regularly and have the experience and expertise to do the job right. If you witness any of these issues on your commercial roof, give us a call at 503-635-8706



Portland Roofing Contractor Since 1980

CCB# 169414