Flat Roof Replacement · FlatGuard®
A flat roof replacement removes the old roofing down to the deck, addresses any damaged decking and installs a new modified bitumen or other low-slope system planned around how your roof drains. QRS replaces worn-out flat roofs across Los Angeles and Orange County with our FlatGuard® low-slope system, starting with a free roof evaluation.
Overview
Flat roofs rarely fail all at once. They wear out: the surface dries and cracks under the Southern California sun, blisters rise where moisture is trapped, laps start to open, and patches pile up around the same drains and walls. Once the problems are spread across the roof, or water has reached the deck, more patching stops making sense. A full tear-off lets us remove layers that may be holding moisture, address damaged decking and build the new roof on a clean, sound surface instead of covering old problems up.
Replacement is also the moment to improve how the roof drains. We study the slope, the low spots where water has been ponding, and whether the drains, scuppers and downspouts can keep up with a winter storm. Where it helps, the scope can include crickets, small raised sections that steer water around curbs and toward the outlets. Not sure your roof has reached this point? A flat roof inspection shows you, with photos, whether a flat roof repair would still do the job.
Compare All Roof Replacement Options →Our Process
How a flat roof replacement works
Roof Evaluation and written scope
We walk the roof, photo-document the membrane, drains and flashings, and put the full scope and price in writing before anything is torn off.
- Membrane wear, blisters and splits
- Ponding and drainage patterns
- Parapets, curbs and penetrations
Tear-off to the deck
The old roofing comes off down to the deck, and we keep debris contained and cleaned up as we go.
- Old layers removed, not roofed over
- Decking inspected and photographed
Drainage and edge prep
Before the new roof goes on, we prepare the edges, drains and scuppers and build any crickets your scope calls for.
New low-slope system
We install the modified bitumen or other low-slope system named in your scope, sealing every lap and flashing each parapet, curb, vent and skylight.
- Laps and seams sealed
- Parapet and wall flashings
- HVAC curbs, vents and skylights
Final walkthrough
When the roof is done, we sit down with you, walk through the photos from tear-off to finish and explain your 10-year workmanship warranty.
Why Choose QRS for Flat Roof Replacement?
A new flat roof is only as good as its drainage and its details, and both are decided long before the last lap is sealed.
Drainage comes first
We plan the new roof around where water actually goes, not simply around what the old roof looked like.
Nothing covered up
A full tear-off means the deck gets seen, and any damage is photographed and explained instead of buried under new layers.
Scope and price in writing
Before the tear-off begins, you know the system, the drainage work and the price.
10-Year workmanship warranty
Your new roof is backed by the QRS Guarantee, our 10-year workmanship warranty, and we review it with you once the roof is finished.
Frequently Asked Questions
Straight answers about flat roof replacement.
How much does a flat roof replacement cost?
It depends on the roof’s size, how many old layers come off, the condition of the deck and the details: drains, scuppers, parapets and rooftop equipment that need flashing. Our Instant Quote gives a quick estimated range, and your written scope and price come after a free roof evaluation, before work begins.
Do you pull the permits?
Yes. When your roofing project needs a building permit, we pull it for you.
What are the signs a flat roof is past repairing?
Common signs include leaks in more than one spot, blisters and splits across much of the surface, soft areas in the deck and patches that keep failing. A free roof evaluation documents what we find with photos, so you can see the reasons behind our recommendation.
Can you put a new flat roof over the old one?
A full tear-off is the standard for a lasting result: taking the old layers off lets us check the deck, get rid of trapped moisture and give the new system a sound surface to start from, rather than hiding problems underneath it. On some commercial buildings, repairing or recoating an existing system that’s still sound can be the right call instead — your roof evaluation will tell you which situation you’re in.
Will a new roof stop water from ponding?
Replacement is the natural time to improve drainage, whether that means adding crickets, building up low spots or changing how water reaches the drains and scuppers. How much can change depends on the roof’s structure, and your written scope spells out the drainage work before anything starts.
Should the gutters and downspouts be replaced at the same time?
Not always, but we check them as part of the scope, because a new roof can only drain as fast as its outlets.
Can a new flat roof have a lighter, reflective surface?
Usually, yes. Light-colored, reflective surfaces bounce back more of the sun’s heat than dark ones, which is worth considering on a roof that sits in full sun most of the year. We’ll go over the surface options that fit your system.
Tell us what you need.
Two minutes. A clear next step. No pressure.
Get a Straight Answer on flat roof replacement
Tell us what’s going on with your roof. A roofer, not a salesperson, looks at it and gives you a clear next step on flat roof replacement, with a written scope and price.
- CSLB licensed, bonded & insured
- 10-year workmanship warranty
- Google customer reviews
