In Carshalton, as everywhere, each glazing bar on a roof lantern has a top capping that clamps the glass onto gaskets. Send photos and we'll tell you what we think has failed.

Signs you need glazing bar and capping repairs
- A capping visibly higher than its neighbours
- Water running down one glazing bar inside
- End caps missing at the bottom of a bar
Common causes we find
Fixings working loose
Screws and clips that hold the capping relax with thermal movement, so the clamp on the glass weakens.
Damage
Ladders, window cleaning or someone stepping on a lantern can bend a capping or unclip it.
Covering Carshalton and nearby
Drier, sunnier parts of the UK are kinder to seals than the wet west, but strong sun ages sealant, gaskets and plastic end caps, and south- or west-facing lanterns can make rooms very warm. Solar control glass and an opening vent help.
London's extensions are often tight to neighbouring walls and roofs. Where a repair needs access over a neighbour's property, we'll tell you in advance so you can arrange it.
We cover Carshalton as part of Greater London, about 9 miles from Westminster.
We also cover nearby Wallington (1 mile), Sutton (2 miles), Mitcham (2 miles).
Guide prices for glazing bar and capping repairs in Carshalton
Most glazing bar and capping repairs jobs come in between £165 and £395 ex VAT (£198–£474 including VAT), per lantern. Towers or scaffold, where needed, are priced into the quote. Your fixed price is confirmed in writing before any work starts.
Do you need permission in England?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in England. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010; we confirm in writing which route applies before any replacement. Listed buildings need listed building consent from the local council for alterations, and conservation areas can have extra controls; like-for-like repairs are treated differently from changes, so check with the council's conservation officer first.
How does it work?
- Send photosWhatsApp or upload a few photos and tell us when it leaks.
- Guide priceWe reply with a guide price and whether a visit is needed.
- Fixed price in writingYou approve the price and the date before anything starts.
- Repair and testWe fix what's failed, water-test where it matters, and send photos.
Glazing bar and capping repairs in Carshalton: questions
Do you cover Carshalton?
Yes. We cover Carshalton, including the SM5 postcode area, as part of Greater London. Send photos by WhatsApp or the form for a free guide price, and we'll confirm the fixed price in writing before any work starts.
Can you repair a lantern someone else installed in Carshalton?
Yes. We repair lanterns whoever fitted them. If yours is still under the installer's warranty, contact them first so you don't affect it.
How much do capping and gasket repairs cost?
Usually £165–£395 ex VAT per lantern depending on how many bars are affected, confirmed in writing before work starts.
Do you repair uPVC and timber lantern bars too?
Yes. Timber lanterns use different beads and cappings, and we repair those as part of timber lantern repairs.
Other lantern repairs in Carshalton
- Upstand and kerb repairs in Carshalton
- Misted glass unit replacement in Carshalton
- Solar control and self-cleaning glass upgrades in Carshalton
- Aluminium roof lantern repairs in Carshalton
- Flat rooflight and skylight repairs in Carshalton
- Leak investigation and inspection in Carshalton
Glazing bar and capping repairs near Carshalton
More about glazing bar and capping repairs · All roof lantern repairs in Carshalton