Cambridge Roofers handles flat roof installations and repairs for homeowners in Grantchester - and this page covers what you can safely do yourself in the short term, and what you really should not attempt.
Call any time. Calls are answered day and night and passed straight to our roofers.
You have spotted a damp patch on the ceiling, or water is coming through somewhere it should not be. The roofer cannot come until next week. What do you do right now? That gap between spotting a problem and getting it properly fixed is where homeowners often cause more damage by attempting a DIY repair, or equally where they let the situation get worse by doing nothing at all.
This page covers what you can reasonably do yourself to limit damage while you wait, what you should not touch, and what a proper flat roof installation or repair from Cambridge Roofers actually involves once we arrive.
We work on flat roofs on extensions, garages, outbuildings, and the main roofs of bungalows and low-pitched properties across Grantchester and the wider Cambridge area. The systems we use are EPDM rubber membrane and torch-on felt. EPDM is a single-ply rubber sheet bonded to the deck - flexible, frost-resistant, and capable of lasting 25 years or more when correctly installed. Torch-on felt is a multi-layer bitumen system, heat-welded in place. Both are reliable when fitted properly; neither will last if the deck beneath them is wet or structurally unsound.
Inside the property, the priority is protecting your belongings and your ceiling from further water damage. These steps are straightforward and sensible.
Flat roofs attract DIY repairs more than pitched roofs do, partly because they look accessible and partly because the damage seems limited. Both assumptions are wrong more often than not.
Do not apply a liquid waterproofing product, sealant, or roof repair tape to the surface without a proper inspection first. A common problem is that the entry point of the water is not where the internal damp patch appears. Water travels along joists and along the underside of the deck before it drops through the ceiling, which means the actual breach in the membrane could be a metre or more from where the damage shows inside. Sealing the wrong spot does not stop the leak; it just delays the roofer finding the real problem and may make it harder to trace.
Do not walk across a flat roof unless you know the deck is sound. An ageing felt system can look intact from the edge but have soft, rotted boards beneath - especially around any drainage points where water has been sitting. A foot through a soft board causes immediate structural damage and is dangerous.
Do not attempt to lift and re-dress a flashing that has pulled away from a wall without knowing how it is fixed. Lead flashings are set into the mortar joint above them; pulling at one without understanding the fixings can break the bond further along and create a larger problem.
Do not apply bitumen paint or cold-applied felt adhesive to an EPDM membrane. The two materials are not compatible - bitumen-based products attack EPDM rubber over time and can cause the membrane to degrade in the area you have treated.
Some flat roof problems can wait a few days for a scheduled visit. Others cannot. Call sooner rather than later if you see any of the following.
A proper flat roof job starts with a survey, not a quote. We get onto the roof and walk it, checking the membrane surface for cracks, splits, lifted edges, and bubbles. We check the deck by feel - soft or springy areas underfoot indicate wet timber below. We inspect every upstand where the roof meets a wall, every edge trim and flashing, and every drainage point. Only once we know the actual condition of the roof can we give you an accurate recommendation and price.
If the result is a repair, we identify the specific entry point and address it with materials compatible with the existing system. If the roof needs replacing, we strip back to the deck, replace any damaged boards, check and correct the fall, and then install the new membrane with properly detailed edges and upstands throughout.
A full EPDM flat roof replacement in this area typically costs between £70 and £120 per square metre, depending on deck condition, access requirements, and the complexity of the flashings and edging. A single-garage roof of around 15 square metres might be £1,200 to £2,000. A 40 square metre extension roof could be £3,000 to £5,000 or more. These figures assume the deck is in good condition; deck replacement adds to the cost and can only be properly estimated after a survey.
A targeted repair for an isolated fault - a failed flashing or a single membrane split - is generally a few hundred pounds. The key is not letting a small problem sit long enough to become a large one.
If you have a flat roof problem on your Grantchester home, extension, or garage, call Cambridge Roofers to arrange a survey. We will tell you exactly what we find, what your options are, and what the work will cost - before anything is agreed.
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Call any time. Calls are answered day and night and passed straight to our roofers.
