Greater London · England
Carshalton Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Carshalton, backed by a one-year guarantee. Call for a quick quote.
- Cracked mastic round a front door frame
- Patchy fillers round a sash window
- Draughty sash windows at the surround
How it works
Most of a good job is in the preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes anything from a few hours to a full day, depending on how many windows. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic is not too thick.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
Before we arrive
- Let us know if you’ve seen damp or leaks
- Mention any sign-in or site rules at work premises
- Let us know about parking restrictions
Get a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email pictures if that’s easy.
Related advice
About our sand mastic in Carshalton
For a listed home or one in a conservation area, ask your local planning authority if consent is needed before window work. Like-for-like sand mastic is often the preferred finish. If you are dealing with draughts and rain around sash boxes and silicone on a period window that looks wrong, we can help.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out.
You get a 12-month guarantee, the same in Carshalton as everywhere else we work.
- Location
- Carshalton (SM5, SM1, SM6)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
When it isn’t the sealant
In fairness, some problems need a different trade:
- Rotten sashes, sills or window boxes (a joiner’s job)
- Sash cords, weights and draught-proofing of the sashes
- Cracked or broken glass
If you’re not sure, just call 0345 464 0079 or email us and we’ll give you a straight answer.
Where we work in Carshalton
- Sash and case windows
- Brick reveals
- Period & listed homes
- Stone surrounds
- Tenement windows
- Timber door frames
Why deal with it now?
New sash windows are a major, costly change, and in listed buildings it may need consent. Where the frames are in good order, new mastic seals the surround. Damp from a failed joint spreads quietly in older London brickwork and timber, and once it shows in Carshalton, the repair is bigger than a sealant job.
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all play a part.
Why Carshalton customers choose us
- One-year guarantee on every job
- Trusted Arbo and Everbuild sealants
- Homes, businesses and hotels
- Approved under the ARBOMaster scheme
Take a look at what affects the cost and our reviews.
Carshalton homes and the weather
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. In a converted house or block, who looks after the windows depends on the lease, so check that before booking.
Schools such as Carshalton High School for Girls are buildings too, and the mastic around its windows and doors needs looking after like any other building’s. If you let a flat or house near Carshalton station, any sash windows need sound mastic to keep draughts and rain out. For an older house near a landmark such as Church of All Saints, the joint between an old wall and a newer frame is usually the first place rain gets in.
Carshalton is about 4 miles south-east of Wimbledon, in Greater London. Anywhere in SM5, our applicators can take on sand mastic. Carshalton is one of 764 towns and villages in Greater London we cover for sand mastic. We also work in London, about 10 miles from Carshalton.
Here we cover the SM5, SM1 and SM6 postcode area for sand mastic. Local streets include Station Road, High Street and The Square, all of which we cover. Main roads around Carshalton include the B277 and B278. Neighbouring places we cover for sand mastic include The Wrythe (1 mile north), Wallington (1 mile east), St Helier (1 mile north-west), Rosehill (1 mile north-west) and Benhilton (1 mile west). Within a short drive, we also cover London (10 miles north), City of Westminster (10 miles north), Marylebone (10 miles north), Kensington (9 miles north), St Pancras (11 miles north) and Shoreditch (12 miles north).
Landmarks near Carshalton
Around Carshalton, our work takes us to homes and buildings near The Railway Tavern, Carshalton Park and Sutton College of Learning for Adults and the streets around them. There’s a railway station in Carshalton itself: Carshalton station. Well-known places in the area include St Helier Hospital (1 mile north-west) and Centrale Croydon (2.9 miles east). Open spaces near Carshalton include Duppas Hill and Sutton Ecology Centre Grounds.
DIY sealant or a professional job?
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
How the job changes by surface
Brick reveals
Loose mastic comes out and deep gaps are packed before pointing.
Stone surrounds
The stone is treated with care when the old mastic comes out.
For landlords and businesses
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we will give you a quote.
If you manage several properties in or around Carshalton, several properties can go on one quote. Just tell us the addresses and what each one needs.
Questions from Carshalton
Can you help a landlord with a rental near Carshalton station?
Yes, landlords and agents are among the people we work for. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll send you a clear quote.
Is parking a problem for a job in Carshalton?
Parking in Carshalton, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
Is it OK to seal over old sealant?
No, it will not last. It can look neat for a few weeks, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
Is there any odour?
Possibly a little. It fades as the sealant cures, and ventilation helps.
What does sand mastic cost?
Every job is different, so each one gets its own quote. For a quick quote, ring 0345 464 0079 or email us and tell us what needs doing and where.
Where is Mr Mastic based?
We are a Crawley-based firm. We work across South East England, London and Scotland.
Can old silicone round a sash window be swapped for sand mastic?
Generally, yes. With the silicone removed and the joint cleaned we point it with sand mastic.
What is sand mastic?
Sand plus a binder based on linseed oil. It’s built up in the joint by hand and shaped to suit the surround.
How to look after the new joints
A little care helps the new joints last. Our advice:
- Leave the new mastic unpainted
- Ask the planning authority about consent for listed or conservation-area homes
- Take care around the mastic when scraping paint
- Have rotten timber repaired before new mastic goes in
When preparing windows for paint, take care around the mastic. It can be damaged by heavy scraping.
Crumbling mastic lets rain into the joint. That water can reach the timber frame and the wall, so renewing it early is worth it.