If you are planning a flat roof replacement or repair in Isleham, knowing exactly what the job involves - from the first inspection to the final tidy-up - helps you plan access, time and budget with no surprises.
Call any time. Calls are answered day and night and passed straight to our roofers.
Most homeowners have a flat roof replaced or repaired only once or twice in their lifetime, so the process is unfamiliar. A job that looks simple from the ground involves several distinct stages, each of which affects the quality and longevity of the finished roof. This page walks through what a proper flat roofing job looks like, from the first visit to when we pack up and leave.
Before anything is quoted or scheduled, the roof needs to be looked at properly. That means getting up onto the surface, not just looking at it from a ladder. A roofer walking the surface can feel soft spots in the deck that are invisible from below. They can check the fall (the angle that drains water to the outlet), clear and inspect the outlet, and assess the condition of all the flashings and upstands around the perimeter.
Inside the building, it is worth checking the ceiling directly below for damp staining, and - where accessible - looking at the underside of the deck from the loft or roof void. Wet or dark timber in the void is an early sign of ongoing moisture ingress even if the ceiling has not yet stained.
A good inspection answers three questions: Is the deck sound? Is the drainage adequate? And is the problem localised (repairable) or widespread (replace)? On a roof in Isleham or a nearby village, we would give you a straight answer to all three before recommending anything.
Most flat roofs on domestic extensions and garages can be accessed from a ladder or short scaffolding tower. Where the roof is higher, or where safe working conditions cannot be maintained with a tower, edge protection or a scaffold platform will be needed. Do not accept a roofer who works from a leant ladder on a roof where the work cannot be reached safely - falls from flat roofs are a significant risk and proper access is not optional.
Before stripping begins, any access points to the interior below are temporarily protected. If the roof is over a habitable room, the occupants should expect a day or two of noise and some disruption to the room below while the deck is exposed.
The old membrane and any insulation above the deck is removed and bagged for disposal. Old felt is heavy, especially if it has absorbed water over the years - several layers of traditional felt on a 20-square-metre roof can weigh a significant amount and all of it needs to come off before the deck can be assessed.
Once the surface is clear, the deck is inspected board by board. Plywood or OSB decking that has softened, delaminated or gone dark with moisture is cut out and replaced. Skipping this step and laying a new membrane over a rotten deck is one of the most common causes of premature failure on refurbished flat roofs. Deck replacement adds cost, but it is not avoidable if the timber is compromised.
Any existing insulation in a cold roof void is also assessed. If it has compacted, shifted or become damp, replacing or upgrading it at this stage costs far less than revisiting it later.
Once rotten boards are replaced and the deck is sound, the surface is swept clean and any protruding fixings are knocked flat or punched in. The fall is checked with a straightedge. If pooling was an issue with the old roof, this is the stage to address it - tapered insulation boards or firring pieces can be added to improve drainage before the new membrane goes down.
The perimeter is also checked. Any timber fascia boards that are split, soft or painted over old rot are replaced. The quality of the edge detail directly affects how well the membrane terminates and how long the perimeter stays watertight.
The membrane system is installed according to the manufacturer's method. For EPDM rubber, this means rolling out the sheet, allowing it to relax and settle flat, then bonding it to the deck using a contact adhesive applied to both surfaces. The membrane is trimmed at the edges, dressed up any upstands, and mechanically fixed or bonded into the termination detail at the perimeter.
For torch-on felt, each layer is bonded by heating the underside with a gas torch as it is rolled out - the bitumen flows and bonds to the layer below. Lap joints are the critical point: they must be fully fused with no voids, or they become entry points for water.
In either case, the outlet is dressed last. The membrane is cut to fit around and into the outlet housing, and the connection is sealed. A roof drain that is poorly detailed at the junction is one of the most common sources of leaks on otherwise sound flat roofs.
Where the flat roof meets a wall, chimney or parapet, the junction is made watertight using lead flashing. Code 4 lead is the standard for most domestic details. The flashing is cut, dressed and fixed into a chase cut into the mortar joint. The mortar joint is then repointed to hold the flashing in place and prevent water tracking behind it.
At the drip edge, the membrane is dressed over a galvanised or aluminium trim that directs water away from the fascia. This detail is often the first to fail on older roofs where the trim was omitted or where the felt was simply folded over the edge and nailed.
Before leaving, the finished roof is walked and checked. All laps and bonds are inspected. The outlet is cleared and flushed. Flashings are pressed home and the mortar is checked. If any section of the membrane has not bonded correctly - detectable as a dull sound when tapped rather than a solid one on EPDM - that section is lifted and re-bonded.
A simple water test can be carried out on smaller roofs by temporarily blocking the outlet and filling the surface with water to a shallow depth, leaving it for an hour and then inspecting the ceiling below. This is not always practical or necessary, but for a roof over a habitable room it is worth asking about.
All stripped felt, packaging and offcuts are removed from site. Gutters are cleared of debris from the strip-out. The area around the building is swept. You should be left with a clean site and a roof you can inspect yourself from a ladder - the finished surface, the outlet, the flashings and the edge trim should all be visible and tidy.
A typical extension or garage flat roof replacement in Isleham or the surrounding villages takes one to two days for a straightforward job. Significant deck replacement or complex flashing details will add time.
Flat roofing work requires dry conditions for adhesives and torch-on systems to bond correctly. Early to mid-autumn and spring are often the best windows. If a roof is actively leaking, temporary waterproofing can be applied to protect the interior while a proper replacement is scheduled.
Newmarket Roofers covers Isleham and nearby places including Mildenhall and Newmarket. Call us to arrange an inspection and we will walk you through what the job involves before any work begins.
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Call any time. Calls are answered day and night and passed straight to our roofers.
