Flat and low slope roofing
Flat roofing Los Angeles: roofs that drain, seams that hold
A flat roof rarely fails all at once. It fails at a seam, a drain or a parapet corner, usually after water has stood there through a few winters. We are California Green Roofing, a licensed crew based in Reseda, and we work on flat and low slope roofs across Los Angeles, from mid-century houses to apartment buildings and storefronts. Flat roof repair, coating and full replacement all start the same way: we find where the water goes, then tell you which one the roof actually needs.
Licensed, bonded and insured
License CSLB #1100046
Crew based in Reseda
Axonometric // where the water goes
Flat roofing guide
Diagnosis
Why is my flat roof leaking, and where does it start?
No roof is truly flat. A low slope roofing deck is built with a fall of roughly a quarter of an inch per foot toward its drains, and nearly every leak we trace begins where that fall was lost or where the membrane changes direction. Four faults account for most of the flat roof repair work we do.
Ponding water // low corner
01
Ponding water on flat roof decks
Water still standing two days after the rain means the slope or the drains are not doing their job. Ponding adds weight, ages a membrane faster than anything else on this list, and finds every weak seam under it. We map the low spots first, because they show where a roof is failing before it leaks, and that is where a flat roof repair is simplest.
02
Open seams and laps
Membranes arrive in rolls and are joined on the roof, so a seam is only as good as the day it was welded or torched. Years of expansion in the heat pull at those joints until one lets go. We probe seams by hand along their length, which finds the soft ones a walk-over misses. A good share of our flat roof repair work starts at a seam like that.
03
Failed flashings and scuppers
Most leaks start at the edges: parapet walls, skylight curbs, vent pipes, air conditioning stands and scupper boxes. Flashing cracks or lifts there long before the open field of the roof wears out, and a scupper packed with grit turns a parapet into a dam.
04
Sun, heat and brittle sheets
Months of hard sun dry out older asphalt based roofs. The surface cracks into an alligator pattern, blisters lift off the deck and the sheet splits underfoot. Once that has spread across a whole roof, patching one spot at a time stops being worth the ladder, and flat roof repair gives way to replacement.
Flat roof leak repair Los Angeles starts with a water test, not assumptions
We trace the entry point before we open anything: the deck read from below where it is reachable, then the roof wetted zone by zone until the water shows itself. Flat roof leak repair that skips this step buys you a second visit in the next storm. When the rest of the roof is sound, many a flat roof repair is finished the same day. A pitched section on the same house is a different job, handled on our roof repair page.
Repair or replace
Flat roof repair or replacement: how we decide
The first question on most calls is simple: is it better to repair or replace a flat roof? Three things decide it: the age of the roof, whether the insulation under the membrane is still dry, and how much of the surface has failed. Age gives the first read, and a core cut confirms the rest. We would rather write up a flat roof repair than a replacement the roof does not need yet, and we will show you the core to prove which one it is.
Roof age
06 yr // repair
0 to 10 years
10 to 20 years
20 and up
01 // path
Flat roof repair
When the membrane is sound and the trouble is local, a flat roof repair is the right answer. We cut out the wet area, dry or replace the insulation under it, patch with the same material the roof is built from and rebuild the flashing around the opening. A flat roof repair done that way is welded into the same membrane rather than sitting on top of it.
Local damage // dry insulation
02 // path
Flat roof coating
A roof that is aging but still dry underneath can often be restored instead. We repair the seams and flashings first, then a silicone or acrylic flat roof coating goes over the whole surface as one reflective skin. It buys years on a sound roof and is wasted on a wet one.
Aging surface // dry insulation
03 // path
Flat roof replacement
Wet insulation, a soft deck or leaks in several places mean the roof has reached the end. A replacement takes everything off to the deck so rotten boards can be swapped, the fall rebuilt and a new membrane run edge to edge, which is the only way to correct drainage properly. By then a flat roof repair only moves the leak along.
Wet insulation // many leaks
Systems
Flat roofing Los Angeles: the systems we install
Flat roofing is a family of membranes rather than one product, and each handles heat, foot traffic and standing water differently. The section drawing shows what they all share: a deck, insulation that builds the fall, a cover board, and the membrane that covers everything.
Section // the layers of a flat roof
TPO roofing
A white single ply sheet, hot air welded into one continuous membrane. TPO roofing sends most of the sun that hits it back to the sky, which keeps the rooms below cooler, and it is our usual choice for a full replacement on a larger roof. It is also the easiest membrane to repair years later.
Welded seams // reflective
PVC membrane
Installed much like TPO and similar to look at, with better resistance to grease and chemicals. We use it where kitchen exhaust lands on the roof, which rules out most other membranes.
Welded seams // grease proof
Modified bitumen roofing
Asphalt sheets reinforced with polymer and laid in two or more plies. Torch down roofing is the form most older Los Angeles houses already have, and a modern two ply cap sheet is tough underfoot, good on smaller roofs and easy to tie into adjacent work.
Two ply // torch down
Silicone roof coating
A liquid applied layer that cures into a seamless skin over a sound roof. Silicone handles ponding better than most sheet membranes, and it carries the restoration path above.
Seamless // over a dry roof
Built up roofing, the tar and gravel system a hot mop crew laid on thousands of Los Angeles roofs, is still out there. We take on flat roof repair work where it still has life left, and when it is worn through we usually replace it with one of the systems above rather than rebuilding it in kind. On a low slope roof that the street can see, some owners compare a membrane with metal roofing instead.
Drainage
Drainage: the part of a flat roof that decides the rest
A membrane keeps water out. Slope and drains get it off the roof, and a roof that clears itself puts far less strain on every seam it has. When we replace a flat roof we correct the drainage first, because a new surface laid over an old fault fails in the same corner.
Slope built into the insulation
Tapered insulation boards build a steady fall toward each drain, and small ridges called crickets steer water around curbs and out of the dead corners behind them. The target is simple: a roof that is dry within two days of rain, with nothing left standing against a parapet.
Drains
Cleared and tested
Scuppers
Sized, with overflow
Crickets
Behind every curb
Edges
New perimeter metal
Overflow scuppers are the safety valve. If a drain blocks during a storm, the overflow lets water leave before it rises over the flashings and into the building. On an older roof with no overflow at all, cutting one in is the smallest job on the scope with the largest effect. It also ends the pattern of booking a flat roof repair for the same corner every winter.
Scupper and cricket // new TPO
Heat and code
Cool roofs, Title 24 and Los Angeles heat
A flat roof takes the sun all day, and a dark one runs far hotter than the air around it. A reflective surface pulls that temperature down, and on low slope work in Los Angeles it is usually a code question as well as a comfort one.
White TPO // reflective surface
01 // code
What Title 24 asks for
The California energy code, Title 24, sets reflectance and emittance requirements for low slope roofing work, and what applies depends on the building, the climate zone and the scope. We confirm that before the permit goes in, and we install membranes and coatings rated by the Cool Roof Rating Council.
02 // comfort
A cooler top floor
White TPO, PVC and silicone send most of the sunlight that hits them back to the sky instead of into the building. Rooms directly under the roof stay noticeably cooler through a long summer, and the air conditioning runs less to hold the same temperature.
03 // lifespan
Less heat, longer life
Heat is what ages a membrane. A roof that runs cooler expands and contracts less every day, so its seams and flashings stay tight for longer than the same roof in black.
Process
Flat roof replacement Los Angeles: our process step by step
Flat roof installation leaves no room for shortcuts, because water finds every one of them. A flat roof repair runs these same steps over a smaller area, and a coating skips the tear off. A tile or shingle roof follows our separate roof replacement process instead.
01
Inspect and core
We walk the roof, map the wet areas and cut a small core so we can see every layer and how much water it is holding.
02
Written scope
You get a written scope with photographs: what we found, and whether it reads as a flat roof repair or a replacement. The estimate is free and written.
03
Permit and protection
We pull the roofing permit with the city, then cover landscaping, walls and the rooms below before anything comes off.
04
Tear off to the deck
Old roofing comes off in sections small enough to close up the same day, and any soft decking is cut out and replaced.
05
Slope and insulation
Tapered insulation and crickets go down to rebuild the fall, topped with a cover board that takes foot traffic.
06
Membrane and seams
The membrane is laid and every seam is welded or torched, then probed by hand along its full length before we move on.
07
Flashings and metal
Parapets, curbs, pipes, drains and scuppers are flashed, and new edge metal finishes the perimeter.
08
Water test and walk
Where the roof allows it we flood test the drains, then walk the finished roof with you and hand over the photographs.
One licensed crew, and a flat roof inspection first
The people on your roof are our own employees, working out of our yard in Reseda under our CSLB license. We are a flat roof specialist Los Angeles owners can drive to, and a flat roof inspection comes first: time on the roof, ending in photographs rather than a sales pitch. One company answers for the whole job, whether it turns out to be a flat roof repair or a full tear off.
Not sure the roof has reached the end? Start with a roof inspection in Los Angeles, which puts the same crew on the roof with a camera and a written report.
An active leak goes straight to our roof leak repair team instead of waiting for a scope.
Timing matters here more than in most cities. Los Angeles does nearly all of its raining between November and March, so we inspect and repair ahead of that window and book full replacements for the dry months, when a roof can be opened and closed again the same day. Flat roof repair does not wait for the dry season, though, and a winter leak is the call we move on first.
Hot air welding // TPO seam
Who we work for
Flat roofs we work on across Los Angeles
Flat and low slope roofs cover a large share of this city: mid-century houses, Spanish style homes behind parapets, dingbat apartment blocks, garages, additions and storefronts. The roofing is similar from one to the next. The way each job has to be run is completely different.
Apartment roof // curbs flashed
01
Homeowners
Mid-century and modern houses, additions, garages and the flat section behind a pitched roof. We close the house in every night and leave the yard clean, because you live underneath the work.
Houses // additions // garages
02
Landlords
Apartment buildings and duplexes where tenants stay in place throughout. We schedule around them, post notices and keep walkways open. A flat roof repair on an occupied building is planned around the people under it: one section at a time, closed in each evening.
Apartments // duplexes
03
Property managers
Documented inspections, photographs and clear scopes that make board approvals straightforward, plus flat roof repair handled quickly when a unit reports a stain on the ceiling.
Reports // upkeep // repairs
04
Commercial owners
Storefronts, offices and light industrial roofs carrying equipment. A flat roof repair here is phased around opening hours so the business below stays open while the roof above is rebuilt.
Retail // office // industrial
Questions
Flat roofing Los Angeles: the questions owners ask
The nine we answer most often, before anyone commits to a repair, a coating or a replacement.
Repair or replace a flat roof?
The core tells us. If the insulation under the membrane comes up dry, a flat roof repair is the right call and we make it. If it comes up wet in more than one place, or the deck flexes underfoot, a patch buys a season and we will say so on the scope.
Why is my flat roof leaking?
Almost never in the open field. It starts at a seam, a parapet flashing, a pipe boot or a drain, and the water then travels along the deck before it shows on your ceiling. That distance is why we test in zones: a flat roof repair has to start where the water gets in, not where it lands.
Do I need a roofing permit?
People usually ask it as, do I need a permit to replace my roof in Los Angeles? For a re-roof or a tear off, yes, and we pull it. Smaller repairs often do not need one, and we confirm that with the city before we start rather than afterwards.
How long does a flat roof last?
Modified bitumen and torch down systems here typically run fifteen to twenty years, welded single ply fifteen to twenty five over a proper fall, and a silicone coating adds about ten to a roof that was sound when it went on. Standing water shortens every one of those.
What causes ponding water?
Too little fall, outlets set too high or blocked, and insulation crushed where people walk. Ponding water on flat roof surfaces is a drainage fault, so tapered insulation and a working scupper solve it where another patch will not.
Can a flat roof be coated instead?
Only over a dry roof, which is why we cut a core first. Wet insulation under a new coating keeps rotting, and no coating warranty covers that. On a sound roof a coating adds years without a tear off, and the seams and flashings get a proper flat roof repair before any of it goes down.
Which flat roofing system fits?
Most houses take a welded single ply membrane or a two ply modified bitumen cap sheet. TPO roofing suits large open roofs, PVC goes where kitchen exhaust lands, torch down roofing handles smaller roofs and awkward tie ins, and silicone belongs on a roof worth keeping a while longer.
What warranty do you give?
Our flat roof warranty covers workmanship for twenty years in writing, and the membrane carries its own manufacturer warranty on top of that. You also keep the photographs of every stage, which is what tells a future owner, or an insurer, exactly what is up there.
How do I choose a contractor?
Flat roof contractors Los Angeles owners hire should be able to show three things: a license number you can look up, the crew who will be standing on the roof, and photographs of a finished job rather than a brochure. When you search flat roof repair near me, the map results are ordered by proximity and profile, not by who is right for your roof, so read the written scope before you sign it.
Book it
Book a flat roof check
Send the address and a line about what the roof is doing: a stain on the ceiling, water that will not clear, or simply its age. We walk the roof and leave a written scope with photographs. Your flat roof estimate is free and written, and if the roof needs only a flat roof repair we will say so rather than writing up a flat roof replacement Los Angeles owners do not need yet.
Flat roof repair Los Angeles // roof check
Call
Service area
Los Angeles, California
License
CSLB #1100046, bonded and insured
Hours
Open daily, 7:00 AM to 10:00 PM