In Mitcham, as everywhere, a cracked pane in a roof lantern needs prompt attention because the glass is overhead. Send photos and we'll tell you what we think has failed.

What you might be seeing
- A visible crack in the outer or inner pane
- A starburst from an impact point
- Broken glass inside the room — keep everyone out of the area
What usually causes it?
Thermal stress
Uneven heating across a pane, edge damage or partial shading can crack glass from the edge.
Spontaneous breakage
Toughened glass can occasionally break without warning, which is why laminated inner panes are recommended overhead.
Roof lanterns in Mitcham
Sun and UV do more damage than rain on many lanterns here: brittle ridge caps, chalky finishes and hardened gaskets. They're cheap to replace before they let water in.
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.
Mitcham is around 7 miles from Westminster, and both are within our Greater London coverage.
Close by, we also cover Morden (1 mile), Wimbledon (2 miles), Streatham (2 miles).
Guide prices for cracked lantern glass replacement in Mitcham
Most cracked lantern glass replacement jobs come in between £295 and £795 ex VAT (£354–£954 including VAT), per glass unit. 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.
Cracked lantern glass replacement in Mitcham: questions
Do you cover Mitcham?
Yes. We cover Mitcham, including the CR4 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 Mitcham?
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.
What does replacing cracked lantern glass cost?
Usually £295–£795 ex VAT per unit depending on size, spec and access, confirmed in writing before work starts.
Why did my glass crack on a sunny day?
Thermal stress — one part of the pane heats faster than another, often where it's shaded or chipped at the edge.
Other lantern repairs in Mitcham
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- Misted glass unit replacement in Mitcham
- Aluminium roof lantern repairs in Mitcham
- Flat rooflight and skylight repairs in Mitcham
- Leak investigation and inspection in Mitcham
- Orangery lantern repairs in Mitcham
Cracked lantern glass replacement near Mitcham
More about cracked lantern glass replacement · All roof lantern repairs in Mitcham