Choosing a flat roof

Flat roofing is the most common style of roof for commercial structures, and for several reasons: 

  • Less expensive to build.
  • Easier and less expensive to maintain.
  • Provides more usable space for the building.
  • Easier to install a green roof.
  • Essential, large equipment installation, i.e. HVAC.

So, if flat roofing is easier to maintain, how do you stop a flat roof from leaking?

Let’s clarify one thing about flat roofing: It isn’t 100% flat. There is a slight slope to a flat roof, enabling it to drain water through specifically placed drains. When flat roofing develops a leak, it is one of the following reasons: 

  • Clogged drains
  • Poor workmanship in construction
  • Poor maintenance and upkeep

To stop flat roofing from leaking, you need to find where the leak is coming from. This is easier than a typical sloped roof because the leak is usually where the water is dripping from, not running down from another area. 

Once you have located the leak, flat roof repair in rain will only be a temporary patch. To repair the flat roofing correctly, the area needs to be thoroughly cleaned and dried, which isn’t possible if it is raining. The patch will include a temporary patch on the roofing surface and inside the structure. Then depending on the type of roofing material, usually a silicone can be brushed on over the leaking area. 

If the leaking is around a protrusion, like the HVAC system, pipes, vents, you’ll want to check the rubber boots and flashing, replace if necessary.  If none of this stops the leak, you’ll need to call a commercial roofing contractor. 

Can you patch a flat roof?

Yes, and how you patch flat roofing, and the type of flat roof repair materials will depend on what type of material the original flat roofing material is in place, the condition of the roofing overall, and the severity of the leak. 

Most flat roofing materials are asphalt, PVC, rubber, or other types of synthetic membranes. Flat roof repair for a rubber or synthetic roofing membrane can usually be done by adhesive patches. Flat roofing of asphalt  can be repaired with caulk or resealed with bitumen.

How often should a flat roof be replaced?

There isn’t an exact deadline for flat roofing lifespan because the various flat roofing materials have a different life expectancy. The general life expectancies for the most common flat roofing materials are: 

  • PVC Flat Roofing System: Twenty to thirty years
  • TPO Flat Roofing System: Twenty to twenty five years
  • Asphalt BUR Flat Roofing System: Twenty to thirty years
  • Coating or Liquid-Applied Flat Roofing System: Fifteen to twenty years

For each of these flat roofing materials, the lifespan is extended or shortened by the quality of the installation and the maintenance and upkeep after installation. How long a roof lasts has a lot to do with the flat roof’s material and installation.

EPDM Flat Roofing: Installed from large rolls of resilient rubber sheets that are strong and elastic. As the temperature changes, this rubber membrane contracts and expands.  The weak point on this type of flat roofing is the seams. They separate over time, allowing water infiltrate. 

TPO Flat Roofing: This style of flat roofing membrane has a white surface, ideal for lowering energy bills in the summer as it reflects the UV rays. Over time though, the hot sun begins to cause this roofing membrane to become brittle and crack, which makes it vulnerable for water infiltration, shortening its lifespan.

Standing Seam Flat Roofing: The seams on this type of flat roofing material are raised to provide a barrier against moisture. However, it is how those standing seams are fastened that are the weak area. The fasteners often become corroded and rusted, then rot and disintegrate. 

How do you know if your flat roof needs replacing?          

Having a professional roofing contractor is the best way to determine if your structure needs flat roof repair or replacement. However, you can check for the following 8 indications that will tell you to have that professional roofing contractor for inspection of your flat roofing. Either way, repair or replacement, the contractor can provide you a written estimate: 

  1. Rips and Tears— An EPDM rubber flat roofing is a common membrane, and while it does provide excellent protection, once it has ripped or torn, that protection is compromised.  Repairs may be possible if not large rips or tears, but if the contractor recommends replacement, don’t ignore the recommendation.  
  2. Cracks — White TPO roofs are excellent for energy efficiency, but as this lightweight roof protection ages, it can develop cracks. Those cracks, common around 15 years, can lead to severe flat roofing issues. 
  3. Ponding Water — No matter what type of flat roofing membrane your structure has, ponding water is not good news. This indicates the drainage is clogged and this is something a professional roofing contractor can correct. Hopefully, you’ve caught it before it began any damage to the membrane and more. 
  4. Flashing Separated  — Flat roofing flashing important to keep water penetration out around seams and protrusions. Early catch of loose or missing flashing can usually be corrected with roof repair. If it has been loose or missing for some time though, there could be damage under the membrane, requiring roof replacement.  
  5. Loose Membrane  — If your flat roofing EPDM membrane is loose and waving in the wind, a repair of reattaching may be possible, but chances are, there is water infiltrated below the membrane and replacement may be needed. 
  6. Loose Fasteners — This is one sign of flat roofing damage that you may not be able to identify unless you’re comfortable getting up on the roof and checking each one. A professional roofing contractor inspection is recommended at least once a year just for things like this. 
  7. Interior Water Spots— If there are water spots and stains on the interior ceiling, your commercial flat roofing likely needs replacing.  At this point, it has likely gone past repair status.  
  8. Roof Leaks — Any leaks coming from your flat roofing to the inside doesn’t leave any guess at the need for roof repair or possible replacement. 

New Flat Roofing

So, you need new flat roofing, take a deep breath, and sign the contract. As a business owner, you’d like to know if this process will interrupt business and how long does it take to replace a flat roof? These are questions that your roofing contractor can answer, but for the time frame, it will depend on the size of the building and the weather. It could be done in 2 days or it could take up to 4 weeks. The average time is a week to two weeks. Need help with your flat roofing in Chambersburg, PA? Call 717-267-0059 today.