Greater London · England
Sand mastic for sash & case windows in Bellingham, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homes and businesses in Bellingham and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Old cement repairs round a window that have failed
- Mastic worn away on windows facing the weather
- Mastic that needs renewing before redecorating
DIY sealant or a professional job?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
A DIY attempt does not rule out a professional job. We remove it and do the joint properly, so just mention it when you contact us.
Sand mastic for homes and businesses in Bellingham
Across Bellingham, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand, finished to suit the masonry. If you have mastic that needs renewing before redecorating and cracked mastic round a front door frame, we can put it right, on stone surrounds, timber door frames and period & listed homes alike.
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 Bellingham is something to talk through when you book.
Each job carries a 12-month guarantee, large or small.
- Where
- Bellingham (SE6, SE26, SE23)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What affects the quote in Bellingham
You’ll get a clear quote before any work starts. It takes into account:
- Working hours on commercial sites
- Any mould that needs treating
- Whether the work is at height
- The size of the job
We do not show prices on the website, because the cost depends so much on the job itself. Call for a quick quote.
What we need to know
To make quoting easier, please include:
- The type of property
- The rough size of the job
- The problem you’ve noticed
- Where the job is, and your postcode
Every job is quoted individually, so the first step is telling us about yours. Just phone 0345 464 0079 or drop us an email with the details.
Sand mastic in Bellingham: local notes
In a converted house or block, who looks after the windows depends on the lease, so check that before you book. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Bellingham is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. For an older house near a landmark such as St Dunstan, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Bellingham is about 2 miles north of Beckenham, in Greater London. Every kind of property in Bellingham is covered for sand mastic, old or new, large or small. Every job comes with our 12-month guarantee. Our area takes in 764 places across Greater London, large and small. London is on our list too, around 6 miles away.
Every address in SE6, SE26 and SE23 is covered for sand mastic, from the main roads to the quietest streets. Local streets include Oslac Road, Orford Road and Aitken Road, all of which we cover. Being close to the A2218, Bellingham is simple for us to get to. Other places close to Bellingham include Southend (1 mile north), Bell Green (1 mile west), Catford (1 mile north-east), Perry Vale (1 mile west) and Sydenham (1 mile west). We also work in nearby towns such as London (6 miles north-west), City of Westminster (8 miles north-west), Marylebone (8 miles north-west), Kensington (9 miles north-west), St Pancras (8 miles north-west) and Shoreditch (7 miles north).
What’s near Bellingham
Locally, jobs take us to homes and businesses close to Sedgehill School, Forster Memorial Park and Allenby Tutorial Trust, among other places. Bellingham has its own railway station: Bellingham station. A little further out are Prefab Museum (1 mile east) and University Hospital Lewisham (1.6 miles north). The countryside around Bellingham includes Downham Woodland Walk and Knight's Hill.
When to call us in Bellingham
Some old mastic was never deep enough. Mastic that is too thin cracks and drops out, which is why we pack deep voids first and get the depth right.
These are the problems we are asked about most:
- Crumbling sand mastic round a window
- Tired mastic found when preparing windows for paint
- Silicone on a period window that looks wrong
- Draughts and rain around sash boxes
Schools such as Elfrida Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
What to look for in a quote
- The length of the guarantee
- How long to leave it before use
- Whether you can choose the colour
- Who turns up on the day
Towns and villages near Bellingham
What else we do in Bellingham
How to look after the new joints
To keep the joints looking good and working properly:
- Make sure water runs off the sill
- Take care around the mastic when scraping paint
- Don’t paint over the new mastic
- Find out about consent before window work on a listed home
Check the mastic when you check the paintwork. Small cracks are easier to deal with early.
Crumbling mastic lets rain into the joint. It can soak into the frame and the surrounding masonry, so renewing it early is worth it.
Landlord and commercial work in Bellingham
For anyone letting property in or around Bellingham, several properties can be quoted together. Send us the addresses and the work at each.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
When something else is needed
It helps to know what we can’t do:
- Decayed frames that need repair
- Damaged stone surrounds
- Cracked or broken glass
If you’re not sure, just phone 0345 464 0079 or email us and we’ll give you a straight answer.
Joints and surfaces we work on
- Brick reveals
- Stone surrounds
- Tenement windows
- Sash and case windows
- Timber door frames
- Period & listed homes
How it works
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The job generally takes a few hours per window, depending on the condition of the joints, including the tidy-up. In Bellingham, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- Each surround is checked first.
- The joint is raked out and cleaned.
- Large voids are packed out.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Getting ready for the visit
- For indoor joints, keep the area dry beforehand if you can
- Tell us about any water getting in
- Keep children and pets away from the work area
Get a quote
Asking for a quote is easy: tell us what needs doing and where. Photos by email help us understand the job.
Related advice
Your questions about sand mastic in Bellingham
Is parking an issue for sand mastic in Bellingham?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Is Bellingham in your area for sand mastic?
Yes, Bellingham is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and let us know what needs doing.
Can I paint the new mastic?
Sand mastic is normally left unpainted, as guidance on traditional windows advises. Talk to us before any painting near it.
What information do you need?
The location, the problem and the rough size of the job. If you can, email a few photos.
Do I have to be there?
We need access to the joints, so we’ll agree that with you when we book. For inside work, that normally means someone being in.
Are you fully insured?
Yes. Mr Mastic is fully insured, and we’ve been doing sealant work for more than 20 years.
Can you do several jobs on one visit?
Yes, we can. Several rooms, windows or areas can go on one quote.
Do I need permission for sand mastic on a listed building?
It’s best to ask your local planning authority first. Sand mastic is often favoured as like for like, but they decide.