Greater London · England
Sand mastic for sash & case windows in Stonebridge, Greater London
Our applicators work in Stonebridge on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly and a 12-month guarantee.
- Gaps round a timber door in stone or brick
- Failed mastic on an exposed elevation
- Wind and rain getting in round a sash window
DIY versus a professional finish
A DIY attempt does not rule out a professional job. We cut it out and start again, so just mention it when you contact us.
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.
Sand mastic for homes and businesses in Stonebridge
Across Stonebridge, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand, finished to suit the masonry. We are often asked to deal with draughts and rain around sash boxes and mastic worn away on windows facing the weather, on brick reveals, sash and case windows and tenement windows.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in, in Stonebridge as anywhere.
We stand behind the work with a one-year guarantee, so you’re not left on your own once the job is done.
- Place
- Stonebridge (NW10, HA9, HA0)
- Region
- Greater London
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What the job involves on each surface
Stone surrounds
We take care not to mark the stone when the old mastic comes out.
Sash and case windows
Most of our sand mastic work is on sash windows. Each joint round the box is raked out and renewed.
When to call us in Stonebridge
Sand mastic slowly weathers. It dries out, cracks and loses its grip on the stone or timber.
Keep an eye out for these signs:
- Gaps between timber frames and stone or brick
- Old cement repairs round a window that have failed
- Gaps round a timber door in stone or brick
- Draughts and rain around sash boxes
Managing a site like The Stonebridge School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Questions to ask before you book
- Are they insured?
- Which sealant they’ll use, and why
- Which colour the sealant will be
- Whether VAT is included
Common questions in Stonebridge
Can you do sand mastic in Stonebridge?
Yes, Stonebridge is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or send us an email and tell us what needs doing.
Can parking be tricky for a visit in Stonebridge?
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.
Does someone need to be in?
It depends on the job. Inside work needs someone to give us access.
What is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.
Will it make a mess?
We keep the work tidy. We protect what’s around the joints.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status and we’re fully insured too.
Is it possible to paint over sand mastic?
Traditional guidance is not to paint over sand mastic. If you are redecorating the window, ask us first and we’ll advise.
Do you work for hotels and businesses?
Yes. Commercial and hotel work is a large part of what we do, as well as homes. Working times can be discussed when we quote.
Nearby places to Stonebridge
Also in Stonebridge
Looking after it afterwards
Simple care keeps the joints in good condition. We recommend:
- Do not paint over the new mastic
- Clear gutters so water does not pour onto the windows
- Avoid heavy scraping on the mastic joint
- Find out about consent before window work on a listed home
Leave the new mastic alone while it firms up. It forms a skin fairly soon but needs longer to fully harden.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry so early renewal protects both.
What we do, step by step
All our tools and materials come with us in the van, so there’s nothing for you to buy. After a quick look at the joints together, we protect the area and start. Most jobs take anything from a few hours to a full day, depending on how many windows. In a London area like Stonebridge, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- Each surround is checked first.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic isn’t too thick.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Preparing for the visit
- Mention any tricky access
- Let us know if you’ve seen damp or leaks
- For business premises, tell us about site rules or sign-in
Ask for a quote
Need a quote? Please call 0345 464 0079 or email us with a few details. We will explain what we’d do and send you a clear quote before work begins.
Read more
Stonebridge homes and the weather
With historic houses such as Pitzhanger Manor (about 2.8 miles south-west) nearby, there’s older building stock in the area around Stonebridge as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. In a converted house or block, who looks after the windows depends on the lease, so check that before booking.
Letting a property close to Harlesden station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about. In the older streets around Saint Michael and All Angels, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Stonebridge is about 2 miles north of Acton, in Greater London. We carry out sand mastic for homes and businesses in Stonebridge, as part of our work across Greater London. Across Greater London, we cover 764 places, and Stonebridge is one of them. We also work in London, about 8 miles from Stonebridge.
Work in NW10, HA9 and HA0 is quoted and booked the same way as anywhere else. Whether your property is on Wood Road, Park Road and Acton Lane or anywhere close by, we can help. Nearby, we also carry out sand mastic in Stonebridge Park (1 mile north-west), Church End (1 mile north-east), Tokyngton (1 mile north-west), Brent Park (1 mile north) and Harlesden (1 mile south-east). We also work in nearby towns such as London (8 miles east), City of Westminster (5 miles east), Marylebone (5 miles east), Kensington (4 miles south-east), St Pancras (6 miles east) and Shoreditch (8 miles east).
What’s near Stonebridge
In Stonebridge, that means homes and buildings near St Claudine's Catholic School for Girls, St. Raphael's Edible Garden and The Swaminarayan School, among other places. There’s a railway station in Stonebridge itself: Harlesden station. A little further out are Neasden Hospital (0.6 miles north) and Brent Museum and Archives (1.5 miles east). Not far away are The Long Water and Hanger Hill Wood.
Why deal with it now?
Before painting the windows, it pays to renew the mastic. Painting over failed mastic doesn’t seal it, and the new mastic is traditionally left unpainted. In a flat in Stonebridge, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
Why us?
- Trusted Arbo and Everbuild sealants
- Anti-fungal sanitary silicone in wet areas
- More than 20 years in sealant work
- Tidy, careful work
Take a look at what affects the cost or our reviews.
Landlord and commercial work in Stonebridge
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
For anyone letting property in or around Stonebridge, several properties can go on one quote. Just tell us the addresses and what each one needs.