Thetford Roofers carries out flat roof replacements and repairs for homeowners in Mildenhall, covering extensions, garages, and bay windows with the right system for the job.
Call any time. Calls are answered day and night and passed straight to our roofers.
Flat roofs on extensions, garages, and outbuildings are practical and space-efficient, but they need the correct specification and regular attention to stay watertight year after year. When something does go wrong, the cause is almost always one of a small number of well-understood problems - poor drainage, failing joints, or perimeter edges that have lifted or cracked. Getting those things right from the start, and keeping an eye on them afterwards, is what keeps a flat roof performing well.
We cover Mildenhall and the surrounding area. If your flat roof is showing signs of trouble, call us to arrange a survey so we can give you a clear picture of what is happening and what your options are.
Before any work starts, a proper survey looks at the roof in three areas: the drainage outlets and falls, the perimeter edges, and the wall junctions. Each one is a common point of failure, and each tells a different story about what is going wrong and why.
Outlets and falls. A flat roof is not truly flat - it should have a slight fall (typically at least 1:80) towards one or more drainage outlets. When the fall is insufficient, or when outlets block with leaves and debris, water sits on the surface. Standing water accelerates the breakdown of felt membranes and puts weight on the deck below. On older felt roofs, this is often where blistering and splits first appear.
Perimeter edges. The edge detail is where the waterproofing membrane terminates. On felt roofs, the edge is usually finished with a timber fascia and a metal drip edge. If the timber rots or the drip edge pulls away, rainwater tracks back under the felt and into the deck. On EPDM rubber roofs, the edge is bonded and mechanically fixed, which makes it more reliable, but it still needs checking where it meets brickwork or soffit boards.
Wall junctions. Where a flat roof meets a vertical wall - at the back of an extension, for example - the membrane needs to be dressed up the wall and secured with a cover flashing. This upstand is often the first thing to fail on an ageing roof. Cracked mortar, lifting lead, or a missing flashing means water gets in behind the membrane, and by the time you see a damp patch on the ceiling inside, the deck may already be wet.
Two systems suit most domestic flat roofs: traditional built-up felt and EPDM rubber membrane. Both are proven, both can be specified correctly for your roof size and exposure, and a good installation of either will serve you well.
Traditional built-up felt uses layers of bitumen-based felt torched or bonded together over an insulated deck. It is a well-understood system that has been used for decades. The quality of the felt and the number of layers matter: a three-layer system with a mineral-finish cap sheet is the standard for a decent domestic job. Expect to pay in the region of £40-£60 per square metre for a competent installation, depending on access, deck condition, and the amount of detailing required.
EPDM rubber is a single-ply membrane bonded to the deck with adhesive. It is flexible, handles movement in the structure well, and is less prone to splitting at joints than older felt systems. EPDM is particularly good on roofs with a complex shape or a lot of detailing around rooflights and upstands. Installed cost typically runs from £60-£90 per square metre. These are general market ranges, not fixed quotes - your actual price depends on the specific job.
In both cases, the condition of the deck underneath matters. A wet or rotten deck needs replacing before new waterproofing goes on top. Laying a new membrane over a damaged deck is a false economy and will shorten the life of the new roof.
This is where most homeowners can make the biggest difference. A flat roof that is checked twice a year and kept clear of debris will outlast one that is ignored. The checks take very little time and do not require any specialist knowledge - you just need to know what to look for and what to do about it.
The best times to check your flat roof are in autumn, once the leaves have fallen, and in spring after the worst of the frost. These two checks catch the problems most likely to cause damage over winter and give you time to deal with anything before the summer.
Clearing outlets is something most homeowners can do safely from a ladder. Beyond that, keep foot traffic on the roof to a minimum - every step on a felt roof risks cracking the surface, particularly in cold weather when the felt is stiff. If you need to get onto the roof to clear a dish or aerial, use a crawl board to spread your weight.
Moss and algae grow on flat roofs in shaded spots. A biocide spray, applied carefully, kills off moss and slows regrowth. Scraping moss off by hand risks damaging the surface of the felt. Let the treatment do the work, then brush off the dead growth gently.
Minor surface cracks in felt can sometimes be treated with a cold-applied bitumen repair compound from a builders' merchant. This is a short-term measure, not a permanent fix. If the same spot keeps opening up, the underlying cause - movement in the deck, or a poorly supported area - needs to be addressed properly.
A professional inspection is worth doing if your flat roof is more than ten years old and has never been surveyed, if you have noticed damp patches inside, or if you can see obvious damage from the ground. A roofer will check the things that are hard to assess from a ladder: the condition of the deck, the quality of the existing waterproofing, and whether any repairs are likely to buy meaningful time or whether replacement is the better value option.
Flat roofs in this region typically last 15-25 years depending on the system, the original installation quality, and how well they have been maintained. An EPDM roof that has been kept clear and had its upstands re-sealed when needed can reach the top of that range. A neglected felt roof may need replacing well before 15 years.
As well as Mildenhall itself, we work across the surrounding area. If you are not sure whether we cover your location, it is worth asking before you arrange a survey.
If your flat roof is leaking, showing damp patches, or simply getting on in years, call Thetford Roofers to arrange a survey. We will look at the roof properly and give you a clear, honest assessment of what needs doing and what it is likely to cost.
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Call any time. Calls are answered day and night and passed straight to our roofers.
