If your flat roof in Burwell is showing damp patches, blisters or pooling water, acting early is nearly always cheaper than waiting until the damage spreads indoors.
Call any time. Calls are answered day and night and passed straight to our roofers.
A flat roof is not truly flat. It is laid to a slight fall, usually between one and three degrees, so that rainwater drains to a gutter or outlet rather than sitting on the surface. When that fall is too shallow, blocked or has settled unevenly over time, water begins to pond. Standing water is the single biggest cause of premature flat roof failure because it puts constant pressure on the membrane and accelerates any small weakness into a leak.
Flat roofs on garages, house extensions and outbuildings across Burwell and nearby villages such as Reach face the same challenge as flat roofs anywhere in this part of Cambridgeshire: temperature swings between seasons cause the membrane to expand and contract. Over years, that movement opens up lap joints, pulls at flashings and cracks older mineral felt that has lost its flexibility.
Most flat roof problems start small and give visible clues well before a leak appears inside. Knowing what to look for lets you act at the repair stage rather than the full replacement stage.
Understanding the cause matters because treating the symptom without fixing the underlying problem just means the repair fails again. The most common causes of flat roof failure are poor original installation, the wrong material for the application, age and lack of maintenance.
Poor installation is behind a large proportion of early failures. A flat roof needs correctly formed drips and upstands, proper bonding of the membrane at all edges, and outlets positioned at the lowest point of the fall. If any of those details are skipped or done badly, water finds a way in.
Inadequate ventilation of the roof build-up causes interstitial condensation, where moisture within the structure condenses on cold surfaces. This rots the deck from below without any water ever coming through the membrane from outside. A cold roof construction needs controlled ventilation; a warm roof construction uses insulation above the deck to keep it warm and dry.
Age is straightforward. Traditional mineral felt has a practical life of around ten to fifteen years in normal conditions. Once it approaches that age, the repair-versus-replace calculation changes. Patching a very old felt roof can be a false economy if the whole surface is near the end of its useful life.
Thermal movement is particularly hard on roofs where the deck boards were not laid with expansion gaps. As timber swells and shrinks across seasons, it pushes up through the membrane at board joints, creating ridges that crack and let in water.
Blocked outlets and gutters are a maintenance issue rather than a structural one, but they cause real damage. A blocked outlet on a flat roof can cause water to back up and eventually overflow into the upstand laps or push under edge trims.
When a repair is no longer sufficient, a replacement roof gives you the opportunity to choose a better-performing system than whatever was originally installed.
EPDM rubber is a single-ply membrane that has become a popular choice for garage and extension roofs. It is bonded to the deck in large sheets, which means very few seams and fewer places for water to get in. EPDM handles temperature movement well and does not become brittle with age in the way that traditional felt does. Manufacturers typically quote a lifespan of several decades for EPDM membranes, though actual performance depends on how well the roof is installed and maintained.
Torch-on felt (also called built-up felt) uses layers of bitumen-modified felt that are heat-welded together on site. A two- or three-layer system is significantly more durable than the old cold-applied felt used on many garage roofs up to the 1990s. Torch-on felt is a cost-effective option and suits roofs where a budget is tight, provided the deck condition is sound.
Whichever system is used, the deck condition underneath it determines how long the new roof will last. A competent installer will assess the deck before quoting and be clear about what needs replacing beneath the membrane.
A repair is appropriate when the membrane failure is localised, the deck is sound, and the rest of the roof still has useful life in it. If a roof is more than fifteen years old, has widespread cracking or blistering, or has a soft or rotten deck, a full replacement will almost certainly cost less in the long run than repeated repairs over the next few years.
Ask any roofer quoting for a repair to tell you honestly whether a patch is the right answer or whether the condition of the wider roof means you will be back for another repair within a year or two.
We cover Burwell and the surrounding area including Reach. When we visit, we check the fall, the outlet positions, the condition of all flashings and upstands, and the deck beneath any problem areas. We will tell you plainly what we have found and what your realistic options are, whether that is a targeted repair or a full re-roof.
Call us to arrange a flat roof survey - we will give you a clear picture of what is going on and an honest recommendation before any work is agreed.
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Call any time. Calls are answered day and night and passed straight to our roofers.
