Greater London · England
Sand mastic for sash & case windows in North Sheen, Greater London
Professional sand mastic in and around North Sheen, with every bit of old sealant taken out first and a 12-month guarantee.
- Open joints round the window box
- Mastic that needs renewing before redecorating
- Wind and rain getting in round a sash window
Should I try it myself first?
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Sand mastic for homes and businesses in North Sheen
Our applicators renew the sand mastic around sash and case windows and doors in stone and brick. Out comes the old, loose mastic, and new mastic is applied and shaped by hand. If you are dealing with silicone on a period window that looks wrong and old sand mastic that has cracked, crumbled or fallen out, we can put it right, whatever the surface.
Many London homes are flats, with windows high above the street. Who looks after the outside of the frames can depend on the lease, so check that first, and access in North Sheen is something to talk through when you book.
Our work is backed for twelve months.
- Location
- North Sheen (TW9, SW14, W4)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Nearby places to North Sheen
Also in North Sheen
Keeping the joints in good condition
Looking after new joints is easy, and it makes a real difference:
- Do not paint over the new mastic
- Take care around the mastic when scraping paint
- Keep sills and gutters clear so water drains away
- Inspect the joints round the windows every year or so
Avoid painting over the new mastic, as traditional guidance advises. Ask us before any decorating around it.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry so early renewal protects both.
What happens if it’s left?
Replacing sash windows is a big decision for a period home 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.
The cost depends on how much there is to do, how hard the old material is to remove and access to the work. You will have a clear quote before any work starts, so you know where you stand.
Why North Sheen clients choose us
- Trusted Arbo and Everbuild sealants
- Approved under the ARBOMaster scheme
- Full insurance on every job
- Experience in homes, commercial sites and hotels
Frames and glazing around North Sheen
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. Historic houses like Kew Palace (about 1 mile north-west) are a reminder that the area around North Sheen has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
If you look after a building such as Kew Riverside Primary School, the mastic around its windows and doors needs looking after like any other building’s. If you let a flat or house near Kew Gardens station, any sash windows need sound mastic to keep draughts and rain out. North Sheen is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
North Sheen is about 3 miles south of Acton, in Greater London. Every kind of property in North Sheen can book us for sand mastic, old or new, large or small. Every job comes with our 12-month guarantee. We cover 764 towns and villages across Greater London, from the larger towns to small villages. We also work in London, around 8 miles away.
Here we cover the TW9, SW14 and W4 postcode area for sand mastic. Streets in the area include Kent Road, Ibis Lane and The Avenue, and we cover them all. If you are just outside North Sheen, we cover Kew (1 mile north), Grove Park (1 mile north-east), Strand-on-the-Green (1 mile north), East Sheen (1 mile south-east) and Mortlake (1 mile south-east). Within a short drive, we also cover London (8 miles east), City of Westminster (6 miles north-east), Marylebone (6 miles north-east), Kensington (4 miles north-east), St Pancras (8 miles north-east) and Shoreditch (9 miles east).
Local landmarks in North Sheen
Typical jobs here are in homes near Kew College Prep, Dukes Meadows and Chiswick School, among other places. North Sheen has its own railway station: Kew Gardens station. A little further out are Barnes Hospital (1.1 miles south-east) and Livat Hammersmith (2.5 miles north-east). Not far away are Kew Gardens Lake and Duke's Hollow.
What we do, step by step
Before we leave, we go over the finished joints with you. The work normally takes a few hours for a single window, longer for several, depending on how much there is to do. In North Sheen, flats, stairs and shared entrances are part of the routine. 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.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Getting ready for the visit
- For business premises, tell us about site rules or sign-in
- Tell us if parking is tricky
- Plan for the work area to be out of bounds to pets and children
How to get a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and add photos by email if you can.
Related advice
What affects the quote in North Sheen
We quote each job individually. These are the things that affect it:
- The number of rooms or windows
- Whether there’s mould to deal with
- The product the joint needs
- Whether old sealant or filler has to be cut out
Some things make a job bigger or smaller: 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.
What to tell us for a quote
You don’t need to know the technical terms. It helps if you can tell us:
- How many joints, rooms or windows are involved
- Whether it has been sealed before
- Where the job is, and your postcode
- What’s wrong with the joints now
Asking for a quote is easy: let us know what needs doing and where. A few pictures by email make the job easier to understand, and we’ll take it from there.
What the job involves on each surface
Stone surrounds
Sand mastic sits naturally against stone. The finish blends with the masonry.
Tenement and terrace windows
Where a building is shared, window work may involve neighbours, so check who is responsible first.
When something else is needed
A few problems are outside what sealant work can do:
- Sashes that need overhauling
- Planning or listed building consent (your local planning authority decides)
- Rotten sashes, sills or window boxes (a joiner’s job)
If in doubt, call 0345 464 0079 or drop us an email and we will say what we think.
Surfaces we seal
- Stone surrounds
- Brick reveals
- Tenement windows
- Period & listed homes
- Timber door frames
- Sash and case windows
North Sheen: your questions answered
Do you work for landlords with property near Kew Gardens station?
Yes. We work for letting agents and landlords as well as householders, and several properties can be quoted together. You can ring 0345 464 0079 or send us an email with the details for a clear quote.
Is North Sheen in your area for sand mastic?
Yes, North Sheen is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status, and we’re fully insured.
Is there any odour?
Some sealants have a smell while they cure, which fades as it sets. Ventilation helps.
Do you take out the old sealant first?
Yes. We cut out all the old sealant and clean the joint before applying anything new.
Is sand mastic better than silicone for my windows?
We will talk it through with you. Sand mastic suits many period homes, and modern sealants suit newer frames.
Are you fully insured?
Yes. We’re fully insured.
Do I need to be at home?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.