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.
Areas around Isleworth we cover
Isleworth and the districts around it, TW7, TW3 and TW5, all sit inside our working area. So does the ground between Isleworth and Hounslow (1 mile), and on towards Heston (2 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
- Rotten kerb sections replaced where the timber has gone soft
- Membrane splits at the upstand cut back and patched
- Lifted flashing or tape removed and renewed
- Age of the rooflight — We weigh the age and condition of the unit before recommending a repair.
- Upstand height and condition — We measure the kerb and probe the timber for softness.
How a repair visit goes
On arrival we agree access and protect the floor. Then a methodical check: glass for misting or cracks, seals for gaps, the frame for movement, the upstand and roof covering for splits or water lying against the kerb. If the cause is obvious and minor, it can usually be sorted as part of the visit. If not, you have the evidence and a priced repair plan, and the choice is yours.
Planning and building rules in England
Two sets of rules matter in England. Planning: a rooflight on a house is normally permitted development if it projects no more than 0.15 m and stays below the highest part of the roof, but flats, listed buildings and Article 4 areas need checking. Building regulations: new openings need approval for the structure and energy performance, and a replacement is a controlled fitting. We are not registered with a competent person scheme, so we notify replacements to building control with a building notice and put the council's fee on the quote.
What to send us
Tell us where the water appears, how long it has been happening and what the weather was doing when it started. A couple of photos from inside and outside, plus the postcode, let us price the visit before you book and plan what the fitter brings.
Common questions in Isleworth
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.
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.
Got a leak or a misted unit in Isleworth? Send photos first and we will tell you what the visit costs before booking.

