Flat Roofs · Chelmsford & Essex
Flat Roofs in ChelmsfordBuilt With Proper Falls,Priced Before We Start
Extension, dormer, garage or porch, a free inspection, a fixed written price and a flat roof where water leaves the building instead of sitting on it. New flat roofs carry a 3-year workmanship guarantee.
Seven years of Essex flat roofing · £1m public liability insured · Free inspections, fixed prices
7 years
Hands-on roofing experience
£1m
Public liability insurance
3 years
Workmanship guarantee on new roofs
Free
Quotes and roof inspections
Fixed
Written prices, never a day rate
The service
What a Flat RoofHas to Get Right
A flat roof is never actually flat. It is a low-pitch roof with a designed fall, and everything about its performance comes down to whether water reaches the outlet or stops somewhere on the way. Ponding, standing water that is still there two days after rain, is the single clearest sign a flat roof was built without a proper fall, and it is what ages a membrane faster than anything the weather can do on its own.
Flat roof work covers repairs to existing coverings, full replacements, and new decks on extensions and dormers. On a replacement we take the old covering off, inspect and renew the deck where it is soft, build in falls with firrings where the structure allows, then lay the new system with correctly formed upstands at every abutment, proper drip edges at the perimeter and an outlet that is actually at the low point.
This is the roof type most often patched into oblivion. Old bitumen felt roofs on garages and sixties extensions get a coat of liquid, then a patch, then another coat, and each layer traps a bit more moisture in the deck below. Once the deck is wet, no surface treatment will save it, and the only honest option is to take it off and rebuild.
Who this is for
- Rear extensions and kitchen extensions with a leaking or ponding roof
- Dormer roofs staining the ceiling in a loft conversion
- Garages, porches and outbuildings with old felt that has blistered or split
- Anyone who has had the same flat roof patched more than twice
- New extensions needing a flat roof built and tied into the main house correctly
The cost of waiting
Standing Water Isa Bill Waiting to Land
Flat roofs fail slowly and then all at once. Water that cannot drain sits on the membrane, freezes and thaws through winter, and works into every seam and blister. Meanwhile the deck underneath, usually timber or chipboard, absorbs whatever gets through and loses strength quietly, out of sight, until somebody stands on it.
Deck rot under an intact-looking surface
The covering can look serviceable while the boards beneath it are soft. Replacing a rotten deck means stripping the roof completely, so the job costs far more than renewing the covering would have done a year earlier.
Ponding accelerating membrane failure
Standing water and freeze-thaw cycling open up seams, blisters and cracks far faster than run-off ever would. A roof with no fall is a roof on a countdown.
Damp reaching the room below
Extension and dormer flat roofs sit directly over habitable rooms. Once water gets past the deck it is in the ceiling, the insulation and often the wall head, taking plaster and decoration with it.
Failed upstands and wall junctions
Most flat roof leaks are not in the middle of the roof, they are where it meets a wall. Short upstands and sealant-only joints let water in behind the covering, where nothing on the surface can stop it.
Common mistakes we get called in to undo
- Painting liquid coatings over a wet deck, sealing moisture in rather than dealing with it.
- Patching blisters repeatedly instead of asking why water is standing there in the first place.
- Accepting a new covering laid over the old one to save a strip-out day.
- Leaving upstands too low at the wall abutment so driving rain gets behind the membrane.
- Ignoring a blocked outlet until the whole roof is holding water like a tray.
Our process
Five Steps From First Call
to Guaranteed Finish
01
Free inspection
We look at the covering, the falls, the outlet, the upstands and the perimeter, and check the deck for movement or softness underfoot rather than judging by appearance.
02
Diagnosis and specification
We identify whether the problem is the covering, the falls, the detailing or the deck, and specify the right system for the roof rather than defaulting to one product for every job.
03
Fixed written quote
One price covering strip-out, deck repairs, insulation where specified, membrane, all trims and disposal. Deck replacement is priced clearly so there are no mid-job surprises.
04
Strip, deck, falls and membrane
Old covering off, deck renewed where needed, falls formed with firrings, then the new system laid with full upstands, drip trims and a correctly positioned outlet.
05
Water test, clear and guarantee
We check drainage, confirm nothing is holding water, clear the site and hand over the 3-year workmanship guarantee, plus the manufacturer-backed membrane guarantee where the system carries one.
What you get
The Difference It Makes
to Your Property
Water that actually leaves
Designed falls and an outlet at the low point mean the roof drains instead of storing rainfall, which is the main reason flat roofs die early.
Fewer seams, fewer failure points
Modern single-ply and rubber systems dramatically reduce the number of joints compared to old three-layer felt, and every joint is a place a roof can leak.
Deck problems caught at strip-out
Taking the covering off is the only way to know the condition of the boards. Soft areas are found and priced while they are visible, not covered over.
Warm-roof options
Where the build-up allows, insulation can go in above the deck, improving the room below and reducing the condensation risk that plagues old cold-deck extensions.
Guaranteed on new work
New flat roofs carry our 3-year workmanship guarantee in writing, alongside the manufacturer-backed membrane guarantee that comes with the system.
One fixed figure
No day rates. The written price covers the work described, so a slow week of weather does not become your problem.
In detail
Systems, Build-Upsand Where Each One Fits
Flat roofing has moved a long way from three-layer bitumen felt, and the right system depends on the size of the roof, the number of penetrations and abutments, what the roof sits over and whether anyone will walk on it.
Warm deck and cold deck
A warm deck puts the insulation above the structural deck and directly under the waterproofing, keeping the deck and the structure on the warm side of the insulation. It is the specification of choice for anything over a habitable room, because it removes the ventilation gap that cold-deck construction depends on and largely designs out interstitial condensation.
Cold deck roofs, insulation between the joists with a ventilated void above, are common on older Essex extensions and garages, and they only work while that void stays properly ventilated. Where an old cold roof has been insulated up to the underside of the deck at some point, the void is gone, and what looks like a leak is often condensation. Diagnosing which of the two you are dealing with changes the whole repair.
Membrane options
EPDM rubber suits simple rectangular roofs, where a single sheet can cover the whole area with no field joints at all. Reinforced bitumen membranes remain a solid, well-proven torch-on or self-adhesive option, particularly on roofs with complex shapes and multiple penetrations where a single sheet is not practical. GRP fibreglass gives a hard, seamless finish that suits balconies and roofs that get walked on.
We specify based on the roof, not on what is quickest to install. The choice, the reasoning and the manufacturer guarantee that comes with each option are all set out with the quote so you can see what you are buying.
Falls, outlets and perimeter details
Falls are formed with tapered firrings on the deck so the surface runs consistently to the outlet. Where the existing structure has no fall at all, common on old garage roofs, we build it in during the rebuild rather than laying a new membrane onto the same flat plane and repeating the problem.
Perimeter detailing is what keeps water off the fascia and out of the wall: drip trims at the eaves, edge trims at the verge, and upstands at every wall abutment carried high enough to sit behind a properly chased flashing rather than relying on sealant at the top edge.
Extensions, dormers, garages and light commercial
Extension roofs are the most common flat roofs we replace, and they almost always abut the main house, so the junction with the existing wall and the tie-in to the pitched roof above are the parts that decide whether the job succeeds. Dormers add cheeks and window abutments, which means more upstands and more lead or trim work in a small area.
Garages, porches and outbuildings are usually simpler and often the best candidates for a single-sheet EPDM installation. On small commercial units the specification logic is the same, though access, roof traffic and keeping the building in use usually shape the programme. See our rubber roofing page for detail on EPDM specifically.
Common questions
Flat Roofs Questions
People Ask First
How much does a new flat roof cost in Essex?
It depends on the area, the system, whether the deck needs replacing and how much detailing there is at the walls. We inspect free of charge and give a fixed written price covering strip-out, deck, membrane, trims and disposal, no day rates.
How long does a flat roof replacement take?
A typical single-storey extension or garage roof is usually a short job measured in days, weather permitting. We give you the expected duration with the quote and tell you immediately if anything found at strip-out changes it.
Can you repair my flat roof instead of replacing it?
If the deck is sound and the fault is localised, a split seam, a failed upstand, a blocked outlet, a repair is often the right answer and we will say so. Once the deck is wet or the roof holds water across its surface, repairs stop being economic.
How long does a flat roof last?
A correctly built modern flat roof with proper falls and good detailing has a long service life, and systems come with manufacturer-backed membrane guarantees. Roofs that pond, or that were laid over an old covering, fail years early regardless of the product used.
What guarantee do I get?
New flat roof installations carry our 3-year workmanship guarantee in writing plus the manufacturer-backed membrane guarantee for the system installed. Repairs are not sold with a workmanship guarantee.
Why does water sit on my flat roof after rain?
Because it has insufficient fall, the outlet is not at the low point, or the deck has deflected. Any of the three means water stays on the membrane, and standing water shortens the life of every flat roof system.
Can you fix a leak over my kitchen extension quickly?
Tell us on the phone that water is getting into the room and we will prioritise making it watertight. Emergency stabilisation and the permanent fix are two separate conversations, and we will be clear about which we are doing.
Do you insulate the roof at the same time?
Where the build-up and heights allow, insulation can be added above the deck as a warm roof, which improves the room beneath and reduces condensation risk. We will tell you at the inspection whether it is practical on your roof.
Which areas do you cover?
Chelmsford, Witham, Southend-on-Sea, Braintree, Maldon, Billericay, Basildon, Brentwood, Wickford, Rayleigh, South Woodham Ferrers and the surrounding Essex villages.
How do I pay?
Card, cash or bank transfer, against a fixed written price agreed before work starts.
Request your free quote
Tell us what is happening. We will arrange a free inspection and come back with a fixed written price, £1m public liability insured, no day rates.
Related work
Other Services That Often Go With This
Rubber Roofing
Single-piece EPDM rubber with a manufacturer-backed membrane guarantee.
View serviceRoofing
Full roof installations and replacements, stripped, felted, battened and finished to last.
View serviceGuttering
Gutter repairs, replacements and clearance to stop water tracking down your walls.
View serviceFlat Roofs Across Essex
- Flat Roofs in Chelmsford
- Flat Roofs in Witham
- Flat Roofs in Southend-on-Sea
- Flat Roofs in Braintree
- Flat Roofs in Maldon
- Flat Roofs in Billericay
- Flat Roofs in Basildon
- Flat Roofs in Brentwood
- Flat Roofs in Wickford
- Flat Roofs in Rayleigh
- Flat Roofs in South Woodham Ferrers
More: roofers in Chelmsford & Essex · all roofing services · areas we cover · about the team · contact us
Get the Flat RoofSorted Properly This Time
Free inspection, an honest verdict on repair or replacement, and a fixed written price. £1m insured, with a 3-year workmanship guarantee on new flat roofs.
Free inspections · Fixed written prices, never a day rate · £1m public liability insurance · 3-year workmanship guarantee on new roofs