Greater London · England
Sand mastic for sash & case windows in Hounslow, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Hounslow, with a 12-month guarantee on every job. Ask us for a quote.
- Cracked mastic round a front door frame
- A silicone bead on a sash window that spoils the look
- Window mastic to renew ahead of painting
Sand mastic for homes and businesses in Hounslow
Sand mastic doesn’t last for ever, leaving gaps round the window. Renewing it closes the gap and tidies the surround. We’re often asked to deal with wind and rain getting in round a sash window and open joints round the window box, on tenement windows, brick reveals and timber door frames.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out, in Hounslow as anywhere.
There’s a 12-month guarantee on every job.
- Place
- Hounslow (TW13)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Keeping the joints in good condition
Once the sealant has cured, a few habits help it last:
- Plan mastic work ahead of painting
- Ask a joiner to look at soft timber first
- Keep sills and gutters clear so water drains away
- Avoid patching sand mastic with silicone
Leave the new mastic alone while it firms up. It skins over quickly, but takes longer to harden fully.
Gaps round a sash box let in draughts and rain. The longer it’s left, the more the joint opens as more mastic falls out.
Why act early in Hounslow
Not every draught comes from the sashes themselves. Open mastic joints round the box can let air in and new mastic seals them. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Putting it right early is much less trouble.
The cost reflects the work involved, not guesswork. That is why we ask about the job first.
Why us?
- Arbo and Everbuild products
- 4.9 on Google from 180+ five-star reviews
- Tidy, careful work
- Any old sealant cut out fully, not covered over
Read what affects the cost and customer reviews.
Towns and villages near Hounslow
Also in Hounslow
What we can’t put right
We’d rather tell you now than do work that won’t last, so these are the limits:
- Decisions on consent for listed homes
- Masonry that needs repairing
- Sashes that need overhauling
If you are not sure, just ring 0345 464 0079 or send us an email and we’ll give you a straight answer.
Surfaces we seal
- Tenement windows
- Period & listed homes
- Timber door frames
- Sash and case windows
- Brick reveals
- Stone surrounds
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Questions from Hounslow
Can parking be tricky for a visit in Hounslow?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
I let a flat near Sunbury station. Can you help?
Yes, we work for landlords and letting agents. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Is the work guaranteed?
You get our 12-month guarantee on every job.
How long will you be here?
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.
Are you insured?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
What sealant do you use?
Each joint gets the product that suits it. Where it moves, gets wet or faces the weather makes a difference, and we will tell you what we are using.
Is it possible to take out silicone and use sand mastic instead?
Usually, yes. With the silicone removed and the joint cleaned, sand mastic is applied by hand.
Do you hold any approvals?
Yes. Mr Mastic is an ARBOMaster approved applicator and we’re fully insured too.
What affects the quote in Hounslow
The quote reflects the job in front of us. We look at:
- Access and height
- Working hours on commercial sites
- Which sealant suits the joint
- Whether there’s mould to deal with
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
Asking for a quote
When you contact us, it’s useful to know:
- Where the job is, and your postcode
- Any access issues, like height or stairs
- Photos by email, if that’s easy
- Roughly how big the job is
Want a quote for sand mastic? Please ring 0345 464 0079 or email us and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Windows and doors in Hounslow
London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
If you look after a building such as Meadhurst Primary School, its window and door frames need their mastic kept sound, just like a home’s. Homes close to Church of St Dunstan include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame. If you let a flat or house near Sunbury station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Hounslow is about 1 mile north of Sunbury-on-Thames, in Greater London. Whether you’re in the middle of Hounslow or further out, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. Our Greater London coverage runs to 764 places, Hounslow among them. We also work in London, around 15 miles away.
Every address in TW13 is covered for sand mastic. We also cover the places around Hounslow: Ashford Common (1 mile south-west), Littleton Common (1 mile south-west), Sunbury-on-Thames (1 mile south), Feltham (1 mile north-east) and Bedfont (1 mile north). We also work in nearby towns such as London (15 miles east), City of Westminster (13 miles north-east), Marylebone (14 miles north-east), Kensington (11 miles north-east), St Pancras (15 miles north-east) and Hampstead (14 miles north-east).
What’s near Hounslow
Locally, jobs take us to homes and businesses close to Sunbury Park, Sunbury Manor School and Sunbury Manor School. For rail, the closest station is Sunbury station, about 0.9 miles south-east. A little further out are Treaty Centre (3.8 miles north-east) and Ashford Hospital (1.9 miles north-west). Green spaces nearby include St Ann's Hill and Staines Reservoirs.
How the visit works
Every visit runs the same way: we check the joints, mask and protect the surrounding surfaces, carry out the job and tidy away. It normally takes a few hours for a single window, longer for several. In a London area like Hounslow, the main things to plan are parking and access: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- First, we look at the surrounds with you and agree what needs doing.
- Old, loose mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic is not too thick.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
Before we arrive
- Let us know about earlier repairs to the joints
- Keep pets and children clear of the area while we work
- For indoor joints, keep the area dry beforehand if you can
Get a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. When it suits you, phone 0345 464 0079 or send us an email.
Advice
What the job involves on each surface
Period and listed homes
On a listed home or in a conservation area, the right material matters. Sand mastic is often the preferred finish.
Timber door frames
Sand mastic is used round timber door frames too. The method is the same as for windows.