Gelligaer guide prices
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.
Where our fitters travel
If you also own a property or a business unit in Blackwood, Pontypridd or Caerphilly, that is no problem. We can survey and quote both, and where it suits, line the fitting days up together. Every address is reached by fitters travelling to it from their current jobs, and CF82, CF81 and NP12 sit comfortably within that pattern.
What we do on the day
- Rotten kerb sections replaced where the timber has gone soft
- Lifted flashing or tape removed and renewed
- Failed sealant cut out, joints cleaned, dried and resealed
- Upstand height and condition — We measure the kerb and probe the timber for softness.
- Age of the rooflight — We weigh the age and condition of the unit before recommending a repair.
How a repair visit goes
A repair visit starts outside. The fitter looks at the roof around the unit for ponding, split membrane, loose flashing and failed sealant, then moves inside to check stains, the frame and the condensation channels. Where it helps, a controlled water test narrows down the entry point. Before leaving, they explain what they found and whether a small fix can be done within the agreed visit, or needs a separate written quote.
Planning, building control and Gelligaer
Welsh rules differ from England's in one important way: rooflights lose permitted development rights in conservation areas, National Parks, AONBs and World Heritage Sites. Elsewhere on a house, a rooflight that projects no more than 150 mm and stays below the highest part of the roof is usually fine. Building regulations still apply to new openings, replacements we fit go through a building notice because we are not scheme-registered, and the energy limit for rooflights is 2.2 W/m²K. A new Welsh Approved Document L takes effect on 4 March 2027.
What to send us
Before booking a visit, send what you can: a photo of the ceiling or reveal where water shows, a photo of the rooflight from outside, the roof covering if you know it, and whether it is one rooflight or several. We use that to price the visit and to bring the right materials.
Common questions in Gelligaer
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.
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.
Do you charge for a leak investigation in Gelligaer?
Yes. Tracing a leak properly takes time on the roof, a close look at the frame and sometimes a water test, so the visit is charged. We confirm the price before you book, so there are no surprises. If a repair is needed beyond what can be done during the visit, it is quoted separately in writing and you decide whether to go ahead.
Send photos of the problem in Gelligaer and we will price the visit before you book it.

