Flat Roof Repair in Los Angeles
We find where the water gets in and repair torch-down, TPO, built-up, and coated flat roofs on homes and commercial buildings. Estimates are free.
- Licensed, bonded & insured
- CSLB #1119699 (C-39)
- BBB Accredited, A rating
Flat Roof Leak Repair Across LA County
Flat roof repair starts with finding where the water gets in, and on a low-slope roof that spot can be several feet from the stain on the ceiling. We repair torch-down modified bitumen, TPO, built-up, and coated flat roofs on homes, apartment buildings, and commercial properties across Los Angeles County. We offer fast response, with same-day visits when crews are available.
For water coming through the ceiling right now, use our 24/7 emergency line, (877) 557-7778, or see our emergency roof leak page. This page covers where flat roofs fail, how each roof type is repaired, what affects the price, and when a repair stops being worth it.
24/7: (877) 557-7778
Sun–Fri, 8 a.m. to 5 p.m.
November to March
CSLB #1119699 (C-39)
Where Flat Roofs Fail: Seams, Drains, Parapets, and Penetrations
Seams and laps
Every flat roof has joints: the overlapping laps on a torch-down roof, the welded seams on TPO, and the plies of a built-up roof. Sun, heat, and building movement work them open over time, usually starting at the edge of a lap. A lap that was never fully bonded can hold for years and then open in one storm.
Blisters
A blister is a raised bubble where air or moisture is trapped between layers. The sun heats the trapped moisture, the bubble grows, and eventually the surface over it cracks.
Alligatoring and cracked cap sheet
As an asphalt roof surface dries out in the sun, it cracks into a grid of small blocks that roofers call alligatoring, and granules wash off the cap sheet. Shallow surface cracks can be sealed or recoated. Cracks that reach the reinforcing mat let water through.
Ponding water and clogged drains or scuppers
Water that stays on the roof after a storm has passed keeps pressing on any weak seam beneath it. Leaves, roof debris, and broken strainers clog drains and scuppers, and low spots where the deck has sagged hold water even when the drains are clear.
Parapets, coping, and wall flashing
Parapet walls leak through open joints in the metal coping on top, cracks in the stucco on the inside face, and loose counterflashing where the membrane turns up the wall. Homes get the same kind of leak where a low roof runs into a higher stucco wall. These leaks usually show up inside along an outside wall.
Penetrations and HVAC curbs
Every pipe, vent, skylight, and equipment curb is an opening with flashing around it. Pitch pans dry out and crack, pipe flashings split, and the flashing around an HVAC curb gets stepped on during service calls.
Call our 24/7 line. We offer fast response, with same-day visits when crews are available.
How We Repair Torch-Down, TPO, Built-Up, and Coated Roofs
A flat roof repair contractor has to match the repair to the roof. A patch in the wrong material may stop a leak for a few weeks and then peel off. This is how we repair each system:
- Torch-down and modified bitumen. A torch-down roof repair starts with cleaning and priming the area. A new piece of modified bitumen is torched or adhered over the damage, extending past it on every side, and finished with cap sheet so the sun does not reach the asphalt. Open laps are heated and pressed back down. Modified bitumen roof repair on a self-adhered roof follows the same steps without the torch. We installed torch-down with a reflective cap sheet on an auto service building in Bell, and repairs use the same materials.
- TPO. A TPO roof repair uses new TPO welded to the old membrane with hot air after the surface is cleaned. Weathered TPO can be hard to weld, so each weld is checked with a probe once it cools.
- Built-up roofs. Cracked or blistered areas are cut out and rebuilt with layers of felt and asphalt or modified bitumen, then covered with gravel or a cap sheet.
- Coated roofs. The coating is cleaned, the damaged spot is repaired, and the patch is recoated. Few materials stick to silicone, so we confirm which coating is on the roof before choosing the repair material.
Recoating an entire worn roof is restoration work rather than repair, and our roof coating page covers it.
Temporary and Permanent Flat Roof Repairs in the Rainy Season
Many flat roof leaks first show up in the first heavy storms of the November-to-March rainy season, and a wet roof limits what can be done:
- Temporary repairs stop water until the roof dries: roof cement and reinforcing fabric worked over an open seam, a sealant made for wet surfaces, or a secured tarp. They are meant to last days or weeks.
- Permanent repairs need a clean, dry surface. Torching modified bitumen, welding TPO, or coating over a wet roof leaves a weak bond, and water trapped under a patch can start a new blister.
When rain is in the forecast, the usual order is a temporary repair or temporary sealing now and a permanent repair once the roof has dried out. Ask for both steps in writing, so you know what the permanent repair will involve.
Commercial Flat Roof Repair for Property Managers
Commercial flat roof repair has extra steps, because tenants work below the roof and several people need to know what is happening. These details speed up the repair:
- A leak log. Note the date, the weather, the exact spot inside, and whether the leak appears only in heavy or wind-driven rain. The pattern often points to the source.
- Roof access. Tell us how to reach the roof, whether by hatch, ladder, or a tenant space, and who holds the keys.
- Equipment history. If the leak is near an HVAC unit, mention recent service. A clogged condensate line or an open cabinet panel can drip into the building and look like a roof leak, and we will tell you when the problem is mechanical.
- Photo records. You get photos of the damage and the finished repair with a written description for the building file, the owner, or a tenant.
What Affects the Price of a Flat Roof Repair
We do not publish repair prices, because two leaks that look alike from inside can need very different work. When you call a flat roof repair company, these are the factors that set the price:
- The time it takes to find the source, especially on roofs with many penetrations
- The roof system, and how many old layers are already in place
- The size of the damaged area, and whether the insulation or decking under it is wet
- Flashing work at parapets, walls, curbs, or drains
- Access, including roof height, ladders or lifts, and getting materials up
- A temporary repair first, if the roof is wet
The estimate is free, and you have it in writing before we start. For how roofing projects are priced in Southern California, see our roof cost guide.
When Patching a Flat Roof Stops Making Sense
Repair makes sense while the roof is mostly dry and the problems are in a few places. Replacement is the better choice when:
- Leaks keep returning in different spots each rainy season
- Test cuts show wet insulation across large areas
- The cap sheet or membrane is cracked or blistered over most of the roof
- The deck is soft or sagging, so water ponds even with clear drains
- The roof already has two layers, so California’s building codes generally do not allow another one on top
A coating can extend the life of a worn roof that is still dry underneath. Past that point, our flat roof replacement page explains the tear-off, insulation, and drainage work. Small repairs do not trigger California’s cool roof rule, according to the California Energy Commission, but replacing or recovering a large share of the roof can.
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Schedule a Flat Roof Repair Estimate
If the roof is leaking now, tell us where the water shows up inside and when it started. Call (877) 557-7778 or use the form below. Overhead Roofing is licensed, bonded, and insured (CSLB #1119699, C-39), and estimates are free.
Get Your Free Estimate
Please fill out the form below, or call: (877) 557-7778
Please fill out the form below, or call:
(877) 557-7778
Need Roof Repair or Replacement? Get a Free Estimate Today!
Don’t wait until a minor issue turns into a significant expense. At Overhead Roofing CA, we make it easy to get expert service fast with no pressure and no hidden fees. From routine roof maintenance to full tear-offs and installations, our team handles every project with precision, honesty, and care.
We specialize in helping LA homeowners and business owners protect their most valuable assets with dependable roofing solutions that last. Our licensed contractors are standing by, ready to inspect your roof, answer your questions, and provide a clear action plan all at no cost to you.
Residential roof repair & replacement
Commercial roofing inspections & upgrades
Emergency leak response & storm damage repair
Financing options available for every budget
Flat Roof Repair and Leak Questions
Why does my flat roof leak only in heavy rain?
Light rain drains away, but a heavy storm raises the water on the roof. Water can then reach a lap or flashing that sits a little higher, back up behind a clogged scupper, or overflow a parapet joint. Wind-driven rain also pushes water sideways into coping and wall flashing. For a flat roof leak repair in Los Angeles, that pattern points us to the higher laps, scuppers, and parapet joints first.
How fast can you get to a flat roof leak?
We offer fast response, with same-day visits when crews are available. The office is open Sunday through Friday, 8 a.m. to 5 p.m., and our 24/7 emergency line, (877) 557-7778, takes calls when water is coming in after hours. During a storm, the first visit may be a temporary repair, with the permanent repair scheduled once the roof dries.
Do you repair flat roofs on houses, or only on commercial buildings?
Both. On houses, we repair flat roofs over garages, carports, patio covers, room additions, and whole mid-century homes, and we do the same work on apartment and commercial buildings. Many flat roofs over living space have little or no attic, so water reaches the ceiling quickly and an early repair limits the damage. The repair methods for torch-down, TPO, built-up, and coated roofs are the same on any building.
Will a patch on my flat roof match the rest of the roof?
Not exactly. New cap sheet looks cleaner and often brighter than cap sheet that has been in the sun for years, and a TPO patch looks whiter than the membrane around it. What matters is that the patch is the same type of material, fully bonded, and protected from the sun. On a coated roof, we recoat over the repair so the surface is continuous.
Should I cut open a blister on my flat roof myself?
No. Cutting a blister opens a path for water, and walking on an old flat roof can crack the surface. Some blisters are stable and only need watching, while others mean water is trapped in the roof. A roofer can tell which is which, and a blister that needs work is cut out and patched in dry weather with matching material.
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