Drain Systems Maintenance for Commercial Roofing

You already know that the roofing protects your commercial building from the scorching Texas sun, but a Houston roofing contractor would also remind you that it repels plenty of precipitation every year as well. The National Oceanic and Atmospheric Administration (NOAA) reports that the average annual rainfall in our area is 49.77 inches. Draining over 4 feet of rain per year takes more than just clean gutters. It requires entire drainage systems specifically designed for commercial buildings. The various elements all work together to deflect water that could damage the roof deck, weaken the foundation and ruin your inventory.

Edge Drains

The majority of low-slope commercial roofing includes drainage across the entire roof as well as at the edges. Edge drains include the following types.

  • Gutters carry the water to the downspout from the roof.
  • Primary scuppers permit water to flow off the roof. They are rectangular holes in the wall of the parapet.
  • Secondary scuppers act as emergency drains in the event that the primary scuppers become clogged. They are located farther up the parapet walls.
  • Downspouts channel the water from the gutters and scuppers into catch basins or directly into the municipal system.

Interior Drains

Water in the center of a large roof is removed by interior drains. Most “flat” roofs have four sloped segments that guide the water to an interior drain on the roof that is capped by a strainer. Then, the drain empties into a drainpipe that transports the water to a standpipe that delivers the rainwater to the ground.

Should your strainers or scuppers become clogged with debris, a pond will form on the roof. Small trees can actually take root in that pond. If there are add-ons like satellite dishes, skylights or HVAC units on the roof, debris can become trapped by them. The weight of the pooled water and any debris will compress your roof and allow water to infiltrate your building. At that point, you would require a Houston roof repair. You might want to have a new interior drain installed too.


The best course of action to make sure that your commercial drainage system is performing properly is to have a Houston roofing company inspect the system during the spring and fall. If you are in an area with numerous trees, you might want to have it inspected more frequently. The roofing technician would be on the lookout for leaks in the drainage systems, blockages in the gutter and the following.

  • Loose objects and an accumulation of debris that must be removed
  • Branches from nearby trees that are rubbing against the roof
  • Granules from the roof covering that could affect the flow of water on the roof
  • Gutters that are not correctly sloped toward the downspout
  • Improperly functioning downspouts that do not channel the water away from the foundation

If you decide to replace your gutters, you might want to have larger ones installed. Your gutters should be metal so that they will not burn if there is a fire. There should not be any debris inside them that could burst into flames. In the Houston area, your gutters should be anchored in place with gutter straps that can withstand hurricane-force winds.

Give Us a Call

The roof on your commercial building must have adequate drainage so that it can do its job. At Paramount Roofing, we have experienced technicians who can visit your property to examine the drainage system. Contact us to schedule an estimate at 713-748-4000. We can arrange for annual or semi-annual roof inspections. If we think that your building would benefit from more frequent inspections, we will let you know. Protect your business with regular inspections that will prevent emergency repairs.