Greater London · England
Sand mastic for sash & case windows in South Croydon, Greater London
Problem with your window and door surrounds in South Croydon? We remove the old material, prepare the joints and seal them properly, with a one-year guarantee.
- Tired mastic found when preparing windows for paint
- Modern sealant on a period surround
- Gaps where the frame meets the masonry
Sand mastic in South Croydon, done properly
We renew sand mastic around sash windows and doors set in stone or brick. The old mastic is raked out, the joint is prepared and new mastic is shaped by hand. We work on stone surrounds, tenement windows and period & listed homes, and common reasons people get in touch are weathered mastic on the most exposed windows and wind and rain getting in round a sash window.
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.
We guarantee the work for a year. If something is not right with it in that time, tell us and we will put it right.
- Place
- South Croydon (CR2, CR8, CR0)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What affects the quote in South Croydon
Some jobs are bigger than they look, and some smaller. What affects the quote:
- Whether old sealant or filler has to be cut out
- Which sealant suits the joint
- The number and length of the joints
- Working hours on commercial sites
What it costs depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before work begins, so you know where you stand.
What we need to know
To help us quote quickly, let us know:
- The type of property
- How many joints, rooms or windows are involved
- Any access issues, like height or stairs
- Where the property is
We do not publish a price list, as no two jobs are quite the same. Instead, we send you a clear quote for your job. To get started, phone 0345 464 0079 or drop us an email.
How it works
We keep the work tidy and contained to the joints we’re treating, so you can carry on as normal. The job generally takes a few hours for a single window, longer for several, and we tell you how long to leave it before we go. In South Croydon, 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.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Preparing for the visit
- Let us know about stairs, lifts or work at height
- Tell us about any previous sealing or DIY attempts
- For business premises, tell us about site rules or sign-in
How to get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we’ll talk you through the work and give you a clear quote.
Advice
Aftercare tips
How long the joints last depends on use and care. Here’s what we suggest:
- Avoid heavy scraping on the mastic joint
- Make sure water runs off the sill
- Ask a joiner to look at soft timber first
- Check the mastic when you check the paintwork
Leave the new mastic alone while it firms up. It skins over quickly, but takes longer to harden fully.
It’s best to renew mastic before painting the windows. Paint over cracked mastic only covers it up.
FAQs for South Croydon
Is parking a problem for a job in South Croydon?
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.
Do you cover South Croydon for sand mastic?
Yes. We work across London and the South East, and South Croydon is part of that. Just phone 0345 464 0079 or email us with a few details of the job, and we will send you a clear quote.
Which is right for my windows, sand mastic or modern sealant?
For period timber windows in stone or brick, sand mastic is often the better fit. On modern frames, we’d normally use a flexible sealant, and we will explain why.
Do you have insurance?
Yes. We are fully insured for every job we do.
I’m a tenant. Can you help?
Of course. Ask your landlord first, and we can send them the quote if that helps.
What does sand mastic cost?
There’s no set price, as it depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Do I need permission for sand mastic on a listed building?
Check with your local planning authority. They decide whether consent is needed for work to your windows.
What guarantee comes with the work?
Our 12-month guarantee covers every job.
Towns and villages near South Croydon
What else we do in South Croydon
What the job involves on each surface
Brick reveals
Sand mastic is also used where timber frames meet brick. It suits older brickwork.
Stone surrounds
Stone openings are rarely perfectly straight, so the gap isn’t the same all the way round. We shape it by hand to follow the stone.
Frames and glazing around South Croydon
Historic houses like Addington Palace (about 2.4 miles east) are a reminder that the area around South Croydon 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. In London conversions and blocks, the lease decides who is responsible for the frames, so check that before booking.
Managing a site like Purley Oaks Primary School? Then its window and door frames need their mastic kept sound, just like a home’s. If you let a flat or house near Sanderstead station, cracked sand mastic around sash windows lets in the draughts tenants complain about. If you live in an older home near Church of St Augustine, the joint between an old wall and a newer frame is generally the first place rain gets in.
South Croydon is about 1 mile south of Croydon, in Greater London. Every kind of property in South Croydon is covered for sand mastic. Every job comes with our one-year guarantee. We cover 764 towns and villages across Greater London, large and small. For nearby work, see our London page, about 10 miles away.
Every address in CR2, CR8 and CR0 is covered for sand mastic, from the main roads to the quietest streets. You will find streets such as Edgar Road, Bynes Road and Grange Road, all of which we cover. We also cover the places around South Croydon: Croydon (1 mile north), Coombe (1 mile north-east), Sanderstead (1 mile south-east), Riddlesdown (2 miles south) and Selsdon (2 miles east). Larger places within reach include London (10 miles north), City of Westminster (11 miles north), Marylebone (12 miles north), Kensington (11 miles north-west), St Pancras (12 miles north) and Shoreditch (12 miles north).
Local landmarks in South Croydon
Around South Croydon, our work takes us to homes and buildings near The Purley Arms, Harris Academy Purley and Duppas Hill, among other places. There’s a railway station in South Croydon itself: Sanderstead station. Other landmarks nearby include Purley War Memorial Hospital (1.2 miles south-west) and Croydon Airport Visitor Centre (1 mile west). The countryside around South Croydon includes Roundshaw Downs and Duppas Hill.
Landlord and commercial work in South Croydon
We also work for property managers and facilities teams. Several sites can go on one quote, and we’re fully insured for the work.
Hotels need rooms back in use, so we plan the work room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
Why deal with it now?
If you’re redecorating, renew the mastic first. Painting over failed mastic doesn’t seal it and traditional guidance is to leave the new mastic unpainted. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in South Croydon, the repair is bigger than the sealant job would have been.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
Why choose Mr Mastic in South Croydon
- One-year guarantee on every job
- Experience in homes, commercial sites and hotels
- Old sealant always removed completely
- Over 20 years’ experience
See our cost guide or what customers say.
When it isn’t the sealant
New sealant cannot fix everything, and we’ll tell you before we start. It will not solve:
- Broken panes
- Timber that has rotted
- Damaged stone surrounds
If in doubt, phone 0345 464 0079 or email us and we will say what we think.
Where we work in South Croydon
- Tenement windows
- Sash and case windows
- Stone surrounds
- Period & listed homes
- Timber door frames
- Brick reveals