Greater London · England
Sand Mastic in Croydon
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for householders, landlords and businesses in Croydon. Fully insured, ARBOMaster approved and guaranteed for a year.
- Old cement repairs round a window that have failed
- A silicone bead on a sash window that spoils the look
- Draughty sash windows at the surround
Sand mastic for homes and businesses in Croydon
Sand mastic doesn’t last for ever, leaving gaps round the window. We rake it out and renew it so the surround looks right again. We work on brick reveals, stone surrounds and tenement windows, and people most often call us about a silicone bead on a sash window that spoils the look and old sand mastic that has cracked, crumbled or fallen out.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. The mastic around them dries out and cracks with age, which is when draughts and damp patches appear in homes in Croydon.
All of our work is guaranteed for twelve months, and the guarantee is the same wherever you are.
- Where
- Croydon (CR0, CR2, CR9, CR8)
- Region
- Greater London
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Landlords, agents and businesses in Croydon
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can go on one quote.
Hotels need rooms back in use, so the work can be planned room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
How we quote for sand mastic
You’ll get a clear quote before any work starts. It’s based on:
- The number and length of the joints
- Which sealant suits the joint
- Any working-time requirements on site
- Any mould that needs treating
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
What we need to know
What to tell us when you ask for a quote:
- Access, such as stairs, a lift or height
- What the problem is, such as mould, gaps, leaks or cracking
- If it’s domestic, commercial or a hotel
- A few photos by email, if you can
We quote each job on its own. Just call 0345 464 0079 or drop us an email with the details.
What sealant work can’t fix
We will always be straight with you, so here’s what sealant cannot fix:
- Crumbling stone or brickwork round the window
- Decisions on consent for listed homes
- Cracked or broken glass
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Sash and case windows
- Timber door frames
- Period & listed homes
- Brick reveals
- Tenement windows
- Stone surrounds
FAQs for Croydon
Is parking a problem for a job in Croydon?
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.
I let a flat near South Croydon station. Can you help?
Yes, we work for landlords and letting agents. You can phone 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before we start.
Will the old sealant be removed?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Do I need to be at home?
It depends on the job. For work indoors, someone needs to let us in, and for outside work we’ll agree access with you when we book.
Can you seal over the old sealant?
No. Fresh sealant doesn’t stick to old sealant, and anything trapped underneath, including mould and water, stays there. We remove it all first.
How do I get a quote for sand mastic in Croydon?
Every job is different, so each one gets its own quote. To get one, ring 0345 464 0079 or drop us an email with a short description of the job.
Is it possible to take out silicone and use sand mastic instead?
Normally, yes. Once the silicone is out and the joint prepared, sand mastic is applied by hand.
What guarantee comes with the work?
You get our 12-month guarantee to all our work.
Places near Croydon
Also in Croydon
What we do, step by step
We work through the job in order: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours per window, depending on the condition of the joints and we leave things clean and tidy. In Croydon, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic is not too thick.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Getting ready for the visit
- On commercial sites, let us know about site rules
- Tell us if parking is tricky
- Keep pets and children clear of the area while we work
How to get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we will explain how we’d tackle it. Whenever you are ready, call 0345 464 0079 or drop us an email.
Advice
How to look after the new joints
Aftercare is simple:
- Find out about consent before window work on a listed home
- Clear gutters so water doesn’t pour onto the windows
- Ask us before painting near the mastic
- Look over the window mastic once a year
Leave the new mastic alone while it firms up. It skins over quickly, but takes longer to harden fully.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry so early renewal protects both.
Can I do it myself?
A DIY attempt doesn’t rule out a professional job. We cut it out and start again.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
Croydon homes and the weather
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. Historic houses like Addington Palace (about 2.5 miles east) are a reminder that the area around Croydon has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
If you let a flat or house near South Croydon station, older sash windows in a rental need their mastic kept sound to keep the weather out. Schools such as Heathfield Academy are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
Croydon is about 9 miles south of London, in Greater London. Jobs in Croydon get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Our area takes in 764 places across Greater London, large and small. For nearby work, see our London page, about 9 miles away.
Our applicators cover all of CR0, CR2, CR9 and CR8 for sand mastic. We cover properties on High Street, Church Road and Ruskin Square and the roads around them. Main roads around Croydon include the A235 and B243. We also cover the places around Croydon: South Croydon (1 mile south), Coombe (1 mile east), Addiscombe (2 miles north-east), Ashburton (2 miles north-east) and Woodside (2 miles north-east). Further out, we also cover London (9 miles north), City of Westminster (10 miles north), Marylebone (11 miles north), Kensington (10 miles north-west), St Pancras (11 miles north) and Shoreditch (11 miles north).
Local landmarks in Croydon
In Croydon, that means homes and buildings near Cambridge Tutors College, Rutherford School and Keg & Grill pub, among other places. There’s a railway station in Croydon itself: South Croydon station. Other landmarks nearby include Croydon Airport Visitor Centre (1.2 miles south-west) and Croydon University Hospital (1.7 miles north). Not far away are Roundshaw Downs and Duppas Hill.
Do you need sand mastic in Croydon?
Some old mastic was never deep enough. Mastic that’s too thin cracks and drops out so we make sure the new mastic is the right thickness.
People normally contact us after spotting one of these:
- Cracked mastic round a front door frame
- Gaps between timber frames and stone or brick
- Patchy fillers round a sash window
- Draughty sash windows at the surround
As a London address, Croydon can be tricky for parking: let us know about parking bays, permits or a driveway.
What your quote should include
- Whether you can choose the colour
- What happens if they find a problem under the old sealant
- Whether they seal over old material or remove it
- Who does the work, and how experienced they are