Greater London · England
Window & door mastic in Benhilton, Greater London
Mastic around window and door frames, sills and patio doors for homes and businesses in Benhilton and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Draughty joints inside around the window
- Mastic that is falling out in pieces
- Untidy mastic left by window fitters
Your questions about window mastic in Benhilton
Can you do window mastic in Benhilton?
Yes, Benhilton is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear price.
Do you work for landlords with property near Sutton Common station?
Yes, we work for landlords and letting agents. You can ring 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before work begins.
Can you do the inside joint as well?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We do one or both.
Can you reach windows above the ground floor?
Yes, in most cases. We plan safe access before the job.
Where do you work from?
We’re based in Crawley, West Sussex, and we work across South East England, London and Scotland.
Do you hold any approvals?
Yes. We hold ARBOMaster approved applicator status, and we are fully insured.
Are you insured?
Yes. Mr Mastic is fully insured, and we’ve been doing sealant work for more than 20 years.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint.
Window mastic in Benhilton, done properly
There are two joints on most windows. The external joint is the weather seal; inside, the joint between frame and plaster stops draughts and tidies the reveal. We seal one or both, depending on what’s needed. Common call-outs are for cold air getting in at the frame edge and black, perished sealant on frames, on uPVC windows, window sills and composite doors.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in, in Benhilton as anywhere.
All our work comes with our one-year guarantee.
- Place
- Benhilton (SM1, SM3, SM5)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Towns and villages near Benhilton
Also in Benhilton
The process
When we arrive, we look over the joints with you first, so you know exactly what we are doing. Surfaces next to the work are protected before we start. Most jobs take anything from an hour or two to a full day, depending on how many frames there are. In a London area like Benhilton, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- First, we go round the frames with you and agree the list.
- We remove the old mastic and clean the frame edge and wall.
- Deep gaps get closed-cell backing rod to set the depth.
- A flexible exterior sealant is applied in a colour to suit the frame.
- We tool each bead neatly and check every joint is closed.
Getting ready for the visit
- Move anything stored near the joints
- Tell us about access, such as stairs, a lift or high-level joints
- Keep pets and children clear of the area while we work
Get a quote
Getting a quote is simple: let us know what needs doing and where, and roughly how big it is. Photos by email help us understand the job, and we’ll come back to you with a quote.
Read more
When it is not the sealant
In fairness, some problems need a different trade:
- A door that needs adjusting, rehanging or new seals
- Broken hinges, locks or handles
- A failed sealed unit that has misted up
Not sure which it is? You can call 0345 464 0079 or drop us an email and we’ll tell you honestly.
Joints and surfaces we work on
- uPVC windows
- Patio & French doors
- Window sills
- Composite doors
- Aluminium frames
- Timber windows & doors
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and getting the depth right matters as much as the look.
Landlord and commercial work in Benhilton
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can be quoted together.
Why act early in Benhilton
Failed mastic is not a reason to replace sound windows. Where the frames are sound, new mastic normally deals with draughts and leaks at the edges. If we find failed glass units or worn seals, we will tell you. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Benhilton, the repair is bigger than the sealant job would have been.
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please phone 0345 464 0079 or email us and we’ll talk you through it.
Why Benhilton customers choose us
- 180+ five-star Google reviews
- Anti-fungal silicone where joints get wet
- Approved under the ARBOMaster scheme
- White, clear, grey or coloured to suit, where the product allows
See our cost guide and our reviews.
Frames and glazing around Benhilton
Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Historic houses like Nonsuch Mansion (about 1.9 miles south-west) are a reminder that the area around Benhilton has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
As a London address, Benhilton can be tricky for parking: let us know about parking bays, permits or a driveway. Letting a property close to Sutton Common station? Then sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. For an older house near a landmark such as All Saints Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Benhilton is about 4 miles south of Wimbledon, in Greater London. Every kind of property in Benhilton can book us for window mastic. Every job comes with our 12-month guarantee. Benhilton is one of 764 towns and villages in Greater London we cover for window mastic. We also work in London, about 10 miles from Benhilton.
Jobs for window mastic in SM1, SM3 and SM5 is quoted and booked the same way as anywhere else. We cover properties on Vale Road, Crown Road and Lewis Road and the roads around them. Other places close to Benhilton include Sutton (1 mile south), St Helier (1 mile north-east), Rosehill (1 mile north-east), Carshalton (1 mile east) and The Wrythe (1 mile east). Further out, we also cover London (10 miles north-east), City of Westminster (10 miles north), Marylebone (10 miles north), Kensington (9 miles north), St Pancras (11 miles north) and Shoreditch (12 miles north-east).
What’s near Benhilton
Typical jobs here are in homes near Greenshaw High School, Manor Park and The Cricketers Inn. Benhilton has its own railway station: Sutton Common station. A little further out are Honeywood Museum (1.4 miles south-east) and Chessington Castle Hill (4.4 miles west). Not far away are Sutton Ecology Centre Grounds and Duppas Hill.
How to look after the new joints
How long the joints last depends on use and care. Here’s what we suggest:
- Air rooms to keep condensation down around windows
- Do not paint over the silicone
- Don’t use solvent cleaners on the joint
- Repaint timber before it’s bare
A yearly look round the frames is enough. Small splits are simple to catch before they leak.
Look out for the warning signs: split or missing mastic, gaps, damp patches inside or black mould on the reveal. If you notice one, it’s time to get the joint looked at.
Surface by surface
uPVC windows
Fitters’ mastic on plastic frames is sometimes thin and rushed. We cut it out, back any deep gaps and reseal properly.
Patio & French doors
Patio and French doors have the longest joints on most houses. The threshold and the bottom corners take the most water, so they get particular care.