Greater London · England
Glazing & conservatory sealant in Clapham, Greater London
Glazing silicone across Clapham and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- Black or yellowed silicone on glass joints
- Water tracking down the inner face of the glass
- Water getting into a conservatory at the joints
Questions from Clapham
Can you help a landlord with a rental near Clapham High Street station?
Yes, we work for landlords and agents. Just call 0345 464 0079 or send us an email and tell us about the property, and we’ll give you a clear quote.
Is Clapham in your area for glazing silicone?
Yes. We work across London and the South East, and Clapham is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job.
What do you need from me for a quote?
Let us know what needs doing and where, with pictures by email if possible. We’ll ask anything else we need to know.
Do you take out the old sealant first?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. Once we have agreed the job, you do not need to watch us work.
Where do you work from?
Mr Mastic is based in Crawley. We cover Clapham and the rest of Greater London.
Are you ARBOMaster approved?
Yes. We’re an ARBOMaster approved applicator, which is run for the Arbo sealant brand.
Can you reseal a frameless shower screen?
Yes. We remove the old sealant and reseal the wall and tray joints.
Glazing silicone in Clapham
Our work covers conservatory joints, rooflights and glass panels, as well as frameless shower screens and glass balustrade bases. The old sealant comes out, the joint is cleaned and new silicone goes in. Typical jobs include water escaping where a screen meets the wall and a quick top-up bead that didn’t last, across glass-to-glass joints, rooflights and shower screens.
Many London homes are flats, with windows high above the street. Who looks after the outside of the frames can depend on the lease, so check that first.
We stand behind the work with a 12-month guarantee.
- Location
- Clapham (SW4, SW8, SW9)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before work begins
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Windows and doors in Clapham
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Carlyle's House (about 1.9 miles north-west) nearby, there’s older building stock in the area around Clapham as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
As a London address, Clapham can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. If you let a flat or house near Clapham High Street station, a shower screen or conservatory joint that leaks is easier to reseal while the property is empty. Schools such as Clapham Manor Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
Clapham is about 3 miles north of Streatham, in Greater London. From the centre of Clapham to the outskirts, glazing silicone is available for homes and businesses alike. Clapham is one of 764 towns and villages in Greater London where we work for glazing silicone.
Postcode districts we cover here for glazing silicone: SW4, SW8 and SW9. Local streets include Grafton Square, Clapham High Street and Houghton Square. You will find Clapham on the B224 and B303, so it’s easy for us to get to with everything needed for glazing silicone. Other places close to Clapham include Stockwell (1 mile east), Little Portugal (1 mile north-east), Clapham Park (1 mile south), South Lambeth (1 mile north-east) and Brixton (1 mile south-east). Further out, we also cover London (3 miles north-east), City of Westminster (3 miles north), Marylebone (4 miles north), Kensington (4 miles north-west), St Pancras (4 miles north) and Shoreditch (5 miles north-east).
Near you in Clapham
In Clapham, that means homes and buildings near Lambeth Academy, Larkhall Park and Trinity Academy and the streets around them. There’s a railway station in Clapham itself: Clapham High Street station. A little further out are Baynard's Castle (3.5 miles north-east) and Harrods (2.6 miles north-west). Not far away are Battersea Park Lake and Knight's Hill.
When it isn’t the sealant
A few problems are outside what sealant work can do:
- Rotten or badly damaged frames
- Water coming through the roof rather than a sealant joint
- A broken pane or roof panel
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we will tell you honestly before booking.
Joints and surfaces we work on
- Glass-to-frame joints
- Glass balustrade bases
- Shower screens
- Rooflights
- Glass-to-glass joints
- Conservatory frames
Towns and villages near Clapham
Other services in Clapham
Why act early in Clapham
Fixing a leaking screen early protects what’s underneath. A small leak can reach the floor below before it shows. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler for homes in Clapham.
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote and we will talk you through it.
What you get with us
- ARBOMaster approved applicator
- Sealant colour chosen to suit
- Quality sealants from Arbo and Everbuild
- More than 20 years in sealant work
Read what affects the cost and what customers say.
How it works
When we get to you, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. After that, the work takes a few hours for most jobs. In Clapham, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- First, we check where the water gets in.
- We remove the old sealant carefully.
- We clean the glass and frame so the new silicone bonds.
- We lay the new bead and tool it smooth.
- We check the finished joints and test with water where it’s safe.
Preparing for the visit
- Tell us about any previous sealing or DIY attempts
- Mention any leaks or damp you’ve noticed
- Keep children and pets away from the work area
Get a quote
Want a quote for glazing silicone? Please phone 0345 464 0079 or send us an email with a few details. We will explain what we’d do and send you a clear quote before any work starts.
Read more
Looking after it afterwards
How long the joints last depends on use and care. Here’s what we suggest:
- Ventilate the conservatory to cut condensation
- Don’t leave a drip for the next storm
- Look over the glazing joints once a year
- Don’t use a blade near the sealant
Don’t use blades or scrapers near the bead when cleaning the glass. Stick to a soft cloth.
Conservatory leaks rarely stay small. Water travels along the frame and into the wall, so get it looked at when you first see it.
Different surfaces, different methods
Glass balustrade bases
Outdoor balustrade joints face the weather. Renewing the sealant keeps water out of the channel.
Glass-to-frame joints
Silicone at the glass edge seals it into the frame. A failed bead lets water in.
Landlord and commercial work in Clapham
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
In hotels, rooms out of use cost money, so the work can be planned room by room. We’ve worked in hotels as well as homes and businesses.
DIY versus a professional finish
A DIY attempt doesn’t rule out a professional job. We cut it out and start again.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.