If you want to know exactly what happens when Downham Market Roofers replace or repair a flat roof in Littleport, this page walks through the whole process.
Call any time. Calls are answered day and night and passed straight to our roofers.
Homeowners who understand what a flat roofing job involves are better placed to ask the right questions, spot shortcuts and make sure the work has been done properly. Too many flat roof problems come down to steps that were skipped - inadequate deck prep, poorly dressed flashings, or a membrane laid without enough adhesive. Knowing what a good job looks like protects you.
We install and repair flat roofs on garages, extensions, outbuildings and smaller commercial buildings in Littleport and the surrounding area. We use EPDM rubber and torch-on felt systems and choose the one that suits the roof in question.
Before any price is agreed, the roof needs to be looked at properly. A site visit typically takes 20-40 minutes on a standard garage or single-storey extension. We check the surface of the existing membrane for splits, blisters and open seams. We look at the condition of the flashings where the roof meets walls, and we check the outlets and gutters to understand how water is draining.
We also check whether the falls are adequate. A flat roof needs a minimum slope of 1 in 80 to drain reliably. In practice, older roofs were sometimes laid dead flat, and that is usually the root cause of standing water and membrane deterioration. If the falls are wrong, the only permanent solution is to correct them when the deck is relaid.
We sound the deck by walking it carefully and checking for soft spots. Soft or spongy areas indicate rot or delamination in the boards below, which means the deck will need stripping and replacing before the new membrane goes on. Finding this at survey stage means no surprises once work starts.
After the survey, we explain what we have found and what needs doing. For a straightforward repair - a split seam, a failed flashing or a localised blister - the scope is usually clear and simple. For a replacement, we will explain whether the deck is reusable, whether insulation needs upgrading and which membrane system we recommend and why.
A written scope of work should specify the membrane system, the number of layers (for felt), the deck specification if it is being replaced, how flashings will be detailed, what the drainage arrangement is and how the perimeter of the roof will be finished. If any of those details are missing from what a roofer tells you, ask for them before work is agreed.
On a replacement job, the first physical step is stripping the existing membrane back to the deck. For torch-on felt, this usually comes away relatively cleanly. Old built-up felt that has been bonded in multiple layers over many years can be more stubborn and sometimes involves chasing old adhesive off the deck boards.
All stripped material is taken from the roof safely and loaded for disposal. The deck boards are then inspected properly once uncovered - it is common to find rot or damage at the edges and around outlets that was not visible from above. Any rotten or inadequate boards are cut out and replaced at this point.
Where new deck boards are going in, they need to be well supported on the joists beneath, fixed correctly and brought to the right level. If the roof is being relaid with improved falls, packer boards or tapered insulation are used to create the slope before the new membrane goes on.
A new or repaired deck needs to be smooth, dry and structurally sound before any membrane is applied. For EPDM, the deck surface should be clean and free of any raised fixings or rough edges that could work through the membrane. A layer of ply is often laid over existing deck boards to create a flat, consistent surface.
For torch-on felt, the deck needs to be dry - torching over a damp deck will trap moisture beneath the membrane and cause blistering from the first warm day. Any knots in the timber deck boards should be sealed to prevent resin bleeding into the felt layers.
If rigid insulation boards are being added to create a warm roof, they are mechanically fixed to the deck at this stage, before the membrane goes on. Getting the insulation flat and the joints tight is important - gaps in the insulation layer create cold bridges and can cause condensation problems later.
For EPDM, a large sheet is unrolled across the deck and positioned carefully before adhesive is applied. The standard approach is to fold the sheet back on itself, apply contact adhesive to both the underside of the membrane and the deck surface, allow it to become touch-dry, then roll the membrane into position. Doing this in sections ensures full, even adhesion without air pockets.
The edges of the EPDM are turned up against any upstands - parapet walls, timber kerbs or wall faces - and bonded with primer and seam tape. Outlets are cut and fitted with purpose-made EPDM outlet collars. Corners, both internal and external, are reinforced with pre-formed patches bonded in place.
For torch-on felt, the base layer is nailed or mechanically fixed to the deck first to hold everything in position. The cap sheet is then torched on, working across the roof with a consistent speed to fully melt and bond each lap. Laps are typically 75-100 mm. Moving too fast leaves cold laps; moving too slowly can blister the sheet. The skill is in reading the material as you go.
The junction between the flat roof membrane and any adjoining wall or parapet is finished with a flashing. On brick or rendered walls, a lead or aluminium flashing is chased into the mortar joint, dressed down over the upstand and sealed. This is one of the most critical details on any flat roof - a flashing that has not been properly chased in, or that has been pointed rather than bedded in the joint, will begin to lift within a few years.
The membrane upstand should extend a minimum of 150 mm up the wall face before the flashing covers it. This ensures that even in heavy rain the water has no chance to track behind the membrane at the base of the wall.
Once the membrane is down and the flashings are dressed, the outlets and gutters are refitted or renewed. A quick check with a hose, or simply waiting for rain, confirms the water runs off correctly and reaches the gutter without ponding. Any adjustments to falls are much easier to make at this point than after the membrane has cured or fully adhered.
All waste material is cleared from the site. Any mortar splashes on the brickwork below the flashing are cleaned off. The finished roof is walked and visually checked - looking for any areas where the membrane has lifted at the edge, any outlet collars that need pressing down, and confirming the perimeter trim is tight.
We will always walk you around the finished work and explain what has been done. You should be able to see the membrane, the edge detail, the flashings and the outlets clearly. If a roofer is not willing to show you the finished details up close, that is a reason to ask why.
If you have a garage, extension or outbuilding in Littleport that needs a flat roof repair or replacement, call Downham Market Roofers to arrange a survey. We cover Littleport and all the nearby villages and will talk you through every stage of the work before anything is agreed.
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Call any time. Calls are answered day and night and passed straight to our roofers.
