Greater London · England
Sand Mastic in Foxbury
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Foxbury, with a one-year guarantee on every job. Ask us for a quote.
- Mastic dropping out of the joint
- Cement or filler used on old window joints that has cracked
- Failed mastic on an exposed elevation
Your questions about sand mastic in Foxbury
Do you cover Foxbury for sand mastic?
Yes. Our work covers London and the South East, and Foxbury is part of that. You can call 0345 464 0079 or send us an email and let us know what needs doing, and we’ll give you a clear quote.
Can parking be tricky for a visit in Foxbury?
Parking in Foxbury, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
How long does sand mastic take?
Typically it takes anything from a few hours to a full day, depending on how many windows. Larger jobs naturally take longer, and we’ll say how long yours will take.
Is it worth trying it myself?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. If it does not work out, we can redo it.
How long does sand mastic take to harden?
It skins over fairly quickly but takes longer to harden fully. We’ll tell you what to expect for your job.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
Is there any odour?
Possibly a little. Any smell clears as the sealant cures, and ventilation helps.
Can I paint the new mastic?
It’s traditionally left unpainted, which is what traditional guidance recommends. Talk to us before any painting near it.
Sand mastic in Foxbury
Sand mastic has long been used to fill the joint between timber frames and masonry. It’s made from sand and a linseed-oil-based binder, applied by hand. On period homes, it looks right where silicone wouldn’t. Common call-outs are for wind and rain getting in round a sash window and mastic worn away on windows facing the weather, across timber door frames, period & listed homes and sash and case windows.
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, and access in Foxbury is something to talk through when you book.
Big or small, you get the same 12-month guarantee in Foxbury and across Greater London.
- Location
- Foxbury (DA14, BR7, DA15)
- Region
- Greater London
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Places near Foxbury
What else we do in Foxbury
Can I do it myself?
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
How it works
There’s no need to move everything out, just the space around the work. Everything nearby is protected, and the work takes anything from a few hours to a full day, depending on how many windows for a typical job. For a job in Foxbury, parking and access are the things to plan: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- We look at the surrounds with you and agree the joints to renew.
- We remove the old, loose mastic.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Preparing for the visit
- Tell us about any previous sealing or DIY attempts
- On commercial sites, let us know about site rules
- Mention any tricky access
How to get a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is. Whenever you’re ready, phone 0345 464 0079 or send us an email.
Advice
Different surfaces, different methods
Tenement and terrace windows
Upper-floor windows need access planning. Tell us the height and we will confirm what’s needed.
Stone surrounds
Stone openings are rarely perfectly straight, so the gap isn’t the same all the way round. We shape it by hand to follow the stone.
Windows and doors in Foxbury
In a converted house or block, who looks after the windows depends on the lease, so check that before you book. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you look after a building such as Chislehurst School for Girls, its window and door frames need their mastic kept sound, just like a home’s. Rented homes near Sidcup station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Foxbury is about 1 mile east of Chislehurst, in Greater London. We carry out sand mastic for homes and businesses in Foxbury, as part of our work across Greater London. Our Greater London coverage runs to 764 places, and Foxbury is one of them. For nearby work, see our London page.
Postcode districts we cover here for sand mastic: DA14, BR7 and DA15. Streets in the area include Kemnal Road, Sydney Road and Carlton Road. Close by, we work in Longlands (1 mile north), Chislehurst (1 mile west), New Eltham (1 mile north-west), Elmstead (2 miles west) and Coldharbour (2 miles north-west). Further out, we also cover London (10 miles north-west), City of Westminster (12 miles north-west), Marylebone (12 miles north-west), Kensington (14 miles north-west), St Pancras (12 miles north-west) and Shoreditch (10 miles north-west).
Around Foxbury
Around Foxbury, our work takes us to homes and buildings near Chislehurst Common, Mead Road Infant School and The Bulls Head Public House and the streets around them. For rail, the closest station is Sidcup station, about 1.2 miles north-east of the centre. Other landmarks nearby include The Glades (3.3 miles west) and Queen Mary's Hospital (0.6 miles east). The countryside around Foxbury includes Summer Hill and The Tarn.
Do you need sand mastic in Foxbury?
Rain on the window surround works into any crack and pushes it out. Exposed elevations normally fail first.
Most people get in touch when they notice one of these:
- Draughts and rain around sash boxes
- Old cement repairs round a window that have failed
- Crumbling sand mastic round a window
- Gaps round a timber door in stone or brick
For an older house near a landmark such as Christ Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
What your quote should include
- Whether VAT is included
- How the surfaces are prepared before sealing
- How much experience the applicator has
- What happens if the job turns out different
What happens if it’s left?
New sash windows are a major, costly change and on a listed home, consent may be needed. If the frames are sound, renewing the mastic deals with gaps and draughts at the surround. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Leaving a failed joint normally makes the job bigger, not smaller, because water and mould keep working on it. If you’re unsure, phone 0345 464 0079 or send us an email for an honest opinion and a quote.
Why book with us
- Quality sealants from Arbo and Everbuild
- 20+ years of sealant experience
- Neat joints and a tidy finish
- Domestic, commercial and hotel work
Read what affects the cost or what customers say.
Work for landlords, hotels and businesses
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
Hotels need rooms back in use, so the work can be planned room by room. Hotel work is part of what we do, alongside homes and businesses.
Aftercare tips
Aftercare is simple, and it makes a real difference:
- Renew mastic before redecorating the windows
- Inspect the joints round the windows every year or so
- Leave the new mastic unpainted
- Make sure water runs off the sill
Make sure water drains away from the window surround. Water sitting against the mastic shortens its life.
Crumbling mastic lets rain into the joint. That water can reach the timber frame and the wall, so renewing it early is worth it.