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.
Fitting across Dartford and nearby
Dartford and the districts around it, DA1, DA2 and DA9, all sit inside our working area. So does the ground between Dartford and Bexley (3 miles), and on towards Swanley (4 miles). When a fitting team is booked, their travel is already in the quoted price, so it does not turn up as a surprise line on the final bill.
What we do on the day
- Failed sealant cut out, joints cleaned, dried and resealed
- Controlled water test where it helps pin down the entry point
- Lifted flashing or tape removed and renewed
- Leak or condensation — We work out whether the water is coming from outside or forming inside on cold glass.
- 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.
Do you need permission in Dartford?
England's rules in short: permitted development usually covers a rooflight on a house roof provided it doesn't stick out more than 0.15 m or rise above the ridge, though a listed building always needs consent and some streets have Article 4 directions. Building regulations apply to new openings, and replacements go through building control; as we are not registered with a competent person scheme, we use a building notice and show the fee on the quote. The energy limit for rooflights in existing homes is 2.2 W/m²K, and the 2026 Approved Document L, in force from 24 March 2027, keeps that figure.
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, DA1 or similar, and how the roof is reached.
Common questions in Dartford
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.
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.
Why is my rooflight leaking?
The usual causes are sealant that has cracked or pulled away, flashing or membrane that has perished at the edges, condensation channels blocked with dirt, water ponding against the kerb, or a seal failing on the glass unit. Sometimes the water is coming in elsewhere and running along to the rooflight. A diagnostic visit finds the real source before anyone starts applying sealant.
Got a leak or a misted unit in Dartford? Send photos first and we will tell you what the visit costs before booking.

