Greater London · England
Sand mastic for sash & case windows in Upton, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homes and businesses in Upton and across Greater London. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Weathered mastic on the most exposed windows
- Gaps between timber frames and stone or brick
- Wind and rain getting in round a sash window
How we handle sand mastic in Upton
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditional guidance is not to paint over it and we’ll advise if you are redecorating. Typical jobs include old sand mastic that has cracked, crumbled or fallen out and wind and rain getting in round a sash window, across sash and case windows, period & listed homes and tenement 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 Upton is something to talk through when you book.
Every job is covered by a 12-month guarantee.
- Place
- Upton (DA6, DA7, DA16)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quote
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Upton: your questions answered
Is Upton in your area for sand mastic?
Yes. We work across London and the South East, and Upton is part of that. You can call 0345 464 0079 or email us and tell us what needs doing.
I let a flat near Bexleyheath station. Can you help?
Yes, rental work is part of what we do. You can call 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Can I add another job to the visit?
Yes. More than one area can be quoted together.
Can sand mastic be painted?
Traditional guidance is not to paint over sand mastic. If you are redecorating the window, ask us first and we will talk you through it.
Does someone need to be in?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
Is consent needed for window work on a listed home?
Check with your local planning authority. They’ll tell you if consent is needed.
How much does sand mastic cost in Upton?
We do not publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
How long does sand mastic take to go off?
It takes a while. It skins first and hardens fully later and we’ll give you an idea for your job.
What we are called out for in Upton
Timber frames move with the seasons. The movement cracks the mastic little by little.
Common reasons people contact us include:
- Old cement repairs round a window that have failed
- Mastic round period door frames that has failed
- Modern sealant on a period surround
- Tired mastic found when preparing windows for paint
Letting a property close to Bexleyheath station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about.
What your quote should include
- How much experience the applicator has
- Whether they seal over old material or remove it
- Which colour the sealant will be
- How the surfaces are prepared before sealing
Windows and doors in Upton
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. Historic houses like Red House (about 0.3 miles south-west) are a reminder that the area around Upton has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
If you live in an older home near Trinity Baptist Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. Upton is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Upton is about 1 mile east of Welling, in Greater London. Jobs in Upton get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Upton is one of 764 places in Greater London where we work for sand mastic. For nearby work, see our London page, about 10 miles away.
Postcode districts we cover here for sand mastic: DA6, DA7 and DA16. Whether your property is on Lion Road, Upton Road and Freta Road or anywhere close by, our applicators can take on the job. Other places close to Upton include Bexleyheath (1 mile east), Crook Log (1 mile west), Blendon (1 mile south-west), Bexley (1 mile south) and Welling (1 mile west). Larger places within reach include London (10 miles west), City of Westminster (13 miles west), Marylebone (13 miles west), Kensington (15 miles west), St Pancras (12 miles north-west) and Shoreditch (10 miles north-west).
Near you in Upton
In Upton, that means homes and buildings near St Catherine's Catholic School, Danson Park and Bexleyheath Academy, among other places. Upton has its own railway station: Bexleyheath station. A little further out are Bexley Hospital (under half a mile south-west) and Broadway Shopping Centre (0.5 miles south-east). Open spaces near Upton include Summer Hill and Wansunt Pit.
For landlords and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
What happens if it’s left?
If you’re redecorating, renew the mastic first. Painting over failed mastic does not seal it and traditional guidance is to leave the new mastic unpainted. Converted houses in London often have a bathroom above someone else’s living room, 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.
No two jobs are quite the same, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Why Upton clients choose us
- We’re fully insured
- 20+ years of sealant experience
- Sanitary silicone with an anti-fungal additive in wet areas
- Rated 4.9 stars on Google
Take a look at what affects the cost and our reviews.
The process
Once we’re on site, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. Most jobs then take a few hours per window, depending on the condition of the joints. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Upton. It helps if you can point us to a visitor permit or a bay close to the door.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- The surface is finished to suit the stone or brick.
Before we arrive
- Let us know about earlier repairs to the joints
- Let us know about parking restrictions
- Clear the area around the work
Get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll talk you through what we’d do. When it suits you, call 0345 464 0079 or drop us an email.
Advice
How the job changes by surface
Sash and case windows
The box of a sash and case window sits in the stone or brick opening. Sand mastic seals the joint round it.
Period and listed homes
Sand mastic is the like-for-like choice for many period homes. If your home is listed, ask your local planning authority about consent.
Places near Upton
What else we do in Upton
When something else is needed
A few problems are outside what sealant work can do:
- Sash cords, weights and draught-proofing of the sashes
- Damaged stone surrounds
- Putty and glazing repairs
If you’re not sure, just ring 0345 464 0079 or drop us an email and we will give you a straight answer before you book.
Where we work in Upton
- Brick reveals
- Sash and case windows
- Period & listed homes
- Stone surrounds
- Tenement windows
- Timber door frames
DIY versus a professional finish
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Sealing over old silicone is the commonest DIY error. 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.