What the job costs in Dulwich
Diagnostic visit
Roof and inside inspected, cause found, written repair price
Reseal and re-flash
Failed sealant and flashing taken out, joints cleaned, resealed and taped
Upstand or membrane repair
Rotten kerb section or roof membrane at the upstand repaired
Guide ranges. The first visit is charged and priced before booking; any repair is priced in writing before work starts. Scaffold, access towers or a crane are priced separately if the job needs them, and building control fees, where a job needs them, are shown as their own line.
Is your address covered?
Looking at a property near Dulwich but not quite in it? We work across SE21, SE24 and SE22 and outwards to Brixton, Camberwell and Upper Norwood. Give us the full postcode when you get in touch, because access, parking and the route for a large unit all depend on the exact street. Those details shape the quote for any job around Dulwich.
What the job includes
- Inside check of stains, frame drainage channels and the reveal
- Rotten kerb sections replaced where the timber has gone soft
- Failed sealant cut out, joints cleaned, dried and resealed
- Age of the rooflight — We weigh the age and condition of the unit before recommending a repair.
- Warranty and who fitted it — We ask who fitted the rooflight and when before working on it.
How a repair visit goes
Most of the effort on a repair visit goes into finding the cause. We start with your account of when it leaks: heavy rain, wind from one direction, or cold mornings, which points towards condensation. That shapes where we look first. Findings are photographed so you can see them for yourself. You then get a clear explanation and, where needed, a written repair quote, fixed before anything further is booked.
Regulations for Dulwich properties
In England, a new rooflight opening generally needs building regulations approval because the roof structure is altered and the glazing must meet energy rules: 2.2 W/m²K for a rooflight in an existing home, or 1.4 W/m²K (or WER Band B) for a roof window. Planning is often not needed on a house: permitted development covers rooflights that stand no more than 0.15 m proud of the roof slope and sit below the highest part of the roof. Flats, listed buildings and areas with an Article 4 direction are different, so we check your address first.
What to send us
Photos help us price the visit. Send one of the stain or drip inside, one of the rooflight from outside if you can reach a safe viewpoint, and a note of when it leaks: in heavy rain, in wind, or all the time. Add the postcode, SE21 or similar, and how the roof is reached.
Common questions in Dulwich
Will resealing fix my leaking rooflight?
Sometimes. If the sealant has simply aged and the flashing, upstand and glass are sound, a careful reseal on a dry day can solve it. If the real problem is ponding water, a low upstand or a perished membrane, fresh sealant will only hide it for a while. We tell you which one you are dealing with before recommending any work, and quote the proper fix in writing.
Should I repair or replace my old leaking rooflight?
It depends on the age and condition of the unit and what has failed. A single perished seal or a blocked channel is worth repairing. A brittle, discoloured dome, a rotten kerb, or several faults at once usually make replacement the better value. After the diagnostic visit we set out both options with prices, so you can decide with the full picture in front of you.
Is it condensation or a leak?
Condensation tends to appear on cold mornings, on the inner face of the glass, and runs down the frame. A leak usually follows rain or wind from a particular direction and often stains the ceiling around the opening. Blocked condensation channels can make the two look alike. Photos and a note of when it happens help us narrow it down before the visit.
Got a leak or a misted unit in Dulwich? Send photos first and we will tell you what the visit costs before booking.

