Plenty of Los Angeles homes and small commercial buildings wear flat or low-slope roofs, and they need a different kind of care than a pitched tile or shingle roof. A flat roof does not shed water the way a sloped one does; it relies on drainage and on the integrity of its membrane and seams. Get those right and a flat roof lasts a long time. Neglect them and it ponds, leaks, and fails early. Knowing what to watch makes all the difference.
A flat roof is never truly flat, it is built with a slight slope so water runs to the drains and leaves. The single most important thing you can do is keep that drainage working. Clear the drains and any debris so water is not dammed up, and watch for water that sits more than a day after rain, which is ponding and a sign the slope or drains need attention, covered on our ponding water page. Standing water is one of the leading causes of flat roof failure.
On a flat roof, the seams where sheets of membrane join, and the spots where vents or units penetrate the surface, are the usual leak points. These are where the membrane is worked hardest and where a small separation lets water in. A visual check for lifting seams, cracks, or gaps around penetrations catches problems early. Our waterproofing and roof repair services address these.
The LA sun is hard on a flat roof membrane, drying it out over time. A reflective coating does two things: it bounces sunlight back to ease the heat load, and it adds a protective layer that extends the membrane's life. On a sound but aging flat roof, a coating is a lower-cost way to buy years before a replacement, covered on our pages on roof coating and roof coating cost. The key is that a coating extends a good roof, it does not fix a failing one.
Flat roofs come in a few systems, and how you care for one depends partly on which you have. TPO is a white, reflective single-ply membrane, while modified bitumen is a tough asphalt-based system, and each has its strengths, covered on our pages on TPO versus modified bitumen and the best flat roof material. Knowing what you have helps you and your roofer keep it in good shape.
| Task | How often |
|---|---|
| Clear drains and debris | Before the rainy season, and after storms |
| Check for ponding | After each significant rain |
| Inspect seams and penetrations | Yearly |
| Consider recoating | As the membrane ages |
If water sits after the rain, if you see lifting seams or a leak below, or if the membrane looks dried and brittle, it is time for a professional look. A roof inspection tells you whether a coating will carry the roof a while longer or whether the membrane has reached the end, in which case our page on flat roof replacement cost covers what comes next. Cared for properly, a flat roof is a reliable, low-drama roof for years.
Coat, repair, or replace, we will tell you which. Call (310) 806-5959 or request an estimate below.
Tell us about your flat roof and we will check the drainage and membrane and give you a written price, with no obligation.