When a flat roof starts leaking in North Walsham, what you do in the hours before a roofer arrives can make a real difference to how much damage follows.
A flat roof leak rarely announces itself at a convenient moment. It is more likely to be during a prolonged spell of rain, in the evening, or when roofers are already booked up. Knowing what you can safely do yourself - and what you should not attempt - is genuinely useful in those first hours and days.
The aim is to slow down water ingress and protect the interior without making the roof harder or more expensive to repair properly. Some well-meant DIY interventions do exactly the opposite.
If water is coming through the ceiling below a flat roof, move anything valuable away from the area and put down towels or containers to collect the drips. If you see the ceiling bulging or sagging, there is likely a significant volume of water sitting above the plasterboard. Carefully make a small hole at the lowest point of the bulge to let the water drain in a controlled place rather than allowing the ceiling to give way unpredictably.
Turn off any electrical circuits that serve light fittings or sockets in the affected room until you are certain no water is running near the wiring. Do not assume it is safe because the room looks dry - water travels along joists and can reach a fitting some distance from where it entered.
If you can access the roof safely and the surface is not wet and slippery, you can attempt a temporary covering. A heavy-duty polyethylene tarpaulin weighted or tied down at the edges will significantly reduce further water ingress while you wait for the repair. The tarpaulin should extend over the edge of the roof onto the fascia or into the gutter - not just laid flat on the membrane - to prevent water tracking back underneath it.
Do not use household plastic sheeting, garden covers or anything that will tear in wind. The covering needs to stay put; one that blows off in the night has achieved nothing. If you cannot secure it properly, it is better not to put it up at all.
Clear any obvious blockages from the drainage outlet or gutter if you can do so safely from the roof edge or a ladder. A blocked outlet in heavy rain will cause water to pond quickly and back up against any weak point in the membrane or flashings.
The temptation when a roof leaks is to go up and apply something - mastic, bitumen sealant, roofing tape, expanding foam. In most cases this makes the problem harder to fix properly and may not stop the leak at all.
Mastic sealant applied over a wet or dirty surface will not bond. It may bridge a gap temporarily but will pull away within weeks, and the roofer who follows you will need to strip it off before making a proper repair. The same applies to most self-adhesive repair tapes that are not specifically designed for the membrane system involved.
Expanding foam has no place anywhere near a flat roof. It traps moisture, distorts the deck surface and is genuinely difficult to remove cleanly. If someone suggests it as a roof repair, treat that as a serious concern about their competence.
Applying torch-on felt or hot bitumen yourself is dangerous without proper equipment and experience. The risks of fire, burns and an improperly bonded repair are all significant. Leave this to a qualified roofer.
When you contact a roofer, give them as much useful information as you can. This helps them come with the right materials and equipment and avoids a wasted visit.
This information allows a roofer to form a working diagnosis before arriving, which means the survey takes less time and any materials needed for an immediate repair can be brought along.
When a roofer arrives to assess a leaking flat roof, the first job is finding the actual source of the ingress. This is often not directly above where the water appears inside - water travels along deck boards and joists before dropping. A thorough inspection covers every junction, flashing, upstand and outlet as well as the membrane itself.
Once the source is found, the roofer will assess whether a targeted repair is appropriate or whether the condition of the overall roof means a repair is only a short-term measure. They should explain both options and give you a clear view of the likely costs of each. A repair to a single lifted flashing or a small membrane split typically costs £150 to £400; a full replacement on a domestic flat roof runs from around £1,200 upwards depending on size and deck condition.
Many domestic flat roofs are covered in felt, and the number of layers and the materials used can vary considerably. EPDM rubber membrane is increasingly common on newer garages, outbuildings and extensions because of its durability and the quality of modern bonding systems. Both can be repaired or replaced; the techniques and materials differ between them.
If your roof was laid before the mid-1990s, there is a reasonable chance it has some form of built-up felt using hot bitumen. These older systems have usually exceeded their design life by now and a leak in one of them is often a trigger for a full replacement conversation.
The flat section of the membrane is rarely where a leak begins. The vulnerable points are where the roof meets something else - a wall, a parapet, a chimney stack, a soil pipe, a rooflight upstand. Flashings are the strips of lead, code-welded felt or EPDM material that bridge these junctions and keep water out. They need to be correctly dressed into a mortar joint or under a coping stone above, and bonded fully to the membrane below.
A flashing that has pulled away from the wall - even by a few millimetres - will allow water in during driven rain. This is a repair that a roofer can usually complete in a morning, but it needs to be done properly: raking out the joint, refixing the flashing and repointing, not simply sealing the gap with mastic.
We cover flat roofing repairs and full replacements in North Walsham and the surrounding area, including Stalham, Mundesley, Trunch, Coltishall, Buxton, Marsham, Holt, Sheringham and Cromer. If you have a flat roof that needs attention, call us to arrange a proper inspection and written assessment of the work required.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
