Greater London · England
Sand mastic for sash & case windows in Crooked Billet, Greater London
Problem with your window and door surrounds in Crooked Billet? We cut out the old, prepare the joints and apply the right sealant, with a 12-month guarantee.
- Draughts and rain around sash boxes
- Failed mastic on an exposed elevation
- Mastic that needs renewing before redecorating
How the job changes by surface
Period and listed homes
On a listed home or in a conservation area, the right material matters. Like-for-like sand mastic is normally favoured.
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We work on single windows or whole elevations.
Sand mastic in Crooked Billet
Sand mastic suits most period window surrounds. Newer frames normally get a flexible sealant instead, and we will talk through which suits your home. Typical jobs include mastic that needs renewing before redecorating and open joints round the window box, on timber door frames, sash and case windows and brick reveals.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first.
The work is guaranteed for twelve months. If something is not right with it in that time, tell us and we will put it right.
- Where
- Crooked Billet (SW19, SW20)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Sand mastic in Crooked Billet: local notes
The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
Crooked Billet is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. If you look after a building such as Wimbledon College, its window and door frames need their mastic kept sound, just like a home’s.
Crooked Billet is about 1 mile west of Wimbledon, in Greater London. Jobs in Crooked Billet get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Our area takes in 764 places across Greater London. For nearby work, see our London page, about 8 miles away.
Every address in SW19 and SW20 is covered for sand mastic, from the main roads to the quietest streets. Whether your property is on Camp Road, Mckay Road and Pepys Road or anywhere close by, we can help. Nearby, we also carry out sand mastic in Copse Hill (1 mile south-west), Wimbledon (1 mile east), Bushey Mead (1 mile south), Wimbledon Chase (1 mile south-east) and Kingston Vale (1 mile north-west). We also work in nearby towns such as London (8 miles north-east), City of Westminster (7 miles north-east), Marylebone (8 miles north-east), Kensington (6 miles north), St Pancras (9 miles north-east) and Shoreditch (10 miles north-east).
Around Crooked Billet
Typical jobs here are in homes near Hollymount School, Cannizaro Park and Ursuline Preparatory School. The nearest railway station is Raynes Park station, roughly 0.9 miles south. Nearby you will also find Southside Wandsworth (2.7 miles north-east) and Wimbledon Museum (0.5 miles east). The countryside around Crooked Billet includes Kew Gardens Lake and Henman Hill.
How we quote for sand mastic
For a quick quote, just ask. The main things that affect it are:
- How many areas need sealing
- The old material and how stubborn it is
- Working hours on commercial sites
- Which sealant suits the joint
The cost depends on the amount of work, how much old material has to come out and access to the work. We give a clear quote before work begins, so you know where you stand.
What we need to know
There’s no need for technical detail. Just tell us:
- The rough size of the job
- Any access issues, like height or stairs
- Whether it’s a home or a business
- Pictures of the joints, sent by email
For a quote, phone 0345 464 0079 or email us with the location and a short description of the problem. You will have a clear quote before work begins.
Places near Crooked Billet
Also in Crooked Billet
What happens if it’s left?
A silicone bead can be quicker, but on period stone or brick it often looks out of place. Sand mastic is the traditional material and finishes neatly against the masonry. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Crooked Billet, the repair is bigger than a sealant job.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all play a part, and we will explain the quote if you ask.
What you get with us
- Any old sealant cut out fully, not covered over
- Tidy, careful work
- Homes, businesses and hotels
- Every job guaranteed for a year
What we do, step by step
Good joint work is mostly preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours for a single window, longer for several. 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.
- Each surround is checked first.
- The joint is raked out and cleaned.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
Preparing for the visit
- Tell us if parking is tricky
- Keep children and pets away from the work area
- Clear the area around the work
Getting a quote
We do not publish a price list, as no two jobs are quite the same. Instead, we send you a clear quote for your job. To get started, phone 0345 464 0079 or drop us an email.
Read more
What we are called out for in Crooked Billet
Most of it is simply age. Even well-laid mastic needs renewing in time, depending on exposure and upkeep.
The most common problems we see are:
- Cracked mastic round a front door frame
- Old cement repairs round a window that have failed
- Gaps between timber frames and stone or brick
- Mastic worn away on windows facing the weather
For an older house near a landmark such as Christ Church, the joint between an old wall and a newer frame is generally the first place rain gets in.
Before you book anyone
- Who does the work, and how experienced they are
- How the surfaces are prepared before sealing
- Is VAT in the price?
- The length of the guarantee
What we can’t put right
To be straight with you, some problems need a different trade:
- Timber that has rotted
- Decisions on consent for listed homes
- Sashes that need overhauling
If you’re not sure, just ring 0345 464 0079 or send us an email and we’ll give you a straight answer before booking.
Surfaces we seal
- Stone surrounds
- Tenement windows
- Period & listed homes
- Brick reveals
- Timber door frames
- Sash and case windows
Crooked Billet: your questions answered
Is parking a problem for a job in Crooked Billet?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Can you help a landlord with a rental near Raynes Park station?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can go on one quote. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we will give you a clear price.
What should I tell you?
Just the basics: where it is, what you’ve noticed and how we reach it. After that, simply call 0345 464 0079 or drop us an email.
How long does sand mastic take to go off?
It forms a skin fairly soon and it hardens fully over a longer time. The weather and joint depth both affect it.
Will the old sealant be removed?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Can sand mastic be painted?
The usual advice is to leave sand mastic unpainted. If you are redecorating the window, ask us first and we’ll talk you through it.
Is it OK to seal over old sealant?
No, and we never do. It may look fine at first, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
Can old silicone round a sash window be swapped for sand mastic?
In most cases. The silicone is cut out and the joint cleaned before the sand mastic goes in.
Aftercare tips
How long the joints last depends on use and care. Here’s what we suggest:
- Ask us before painting near the mastic
- Check with your local planning authority if your home is listed
- Make sure water runs off the sill
- Ask a joiner to look at soft timber first
Make sure water drains away from the window surround. Constant wetting wears the mastic faster.
An open joint round the box lets weather through. The longer it’s left, the more the joint opens.