Greater London · England
Sand Mastic in Thornton Heath
We cover Thornton Heath for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- Open joints round the window box
- Silicone on a period window that looks wrong
- Crumbling sand mastic round a window
Sand mastic in Thornton Heath
Sand mastic doesn’t last for ever, leaving gaps round the window. Renewing it closes the gap and tidies the surround. Typical jobs include old cement repairs round a window that have failed and old sand mastic that has cracked, crumbled or fallen out, on period & listed homes, tenement windows and stone surrounds.
Many London homes are flats, with windows high above the street. In a converted house or block, the lease usually says who is responsible for the windows, so it’s worth checking before booking, and access in Thornton Heath is something to talk through when you book.
Whatever the size of the job, it’s backed by our 12-month guarantee in Thornton Heath and across Greater London.
- Place
- Thornton Heath (CR7, SW16, SE25)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Landlords, agents and businesses in Thornton Heath
Hotels need rooms back in use, so we plan the work room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Also near Thornton Heath
Also in Thornton Heath
What affects the quote in Thornton Heath
The price is agreed before any work begins. It takes into account:
- The old material and how stubborn it is
- The type of sealant required
- The size of the job
- Any mould that needs treating
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all play a part.
Helping us quote
To help us quote quickly, please include:
- If someone has resealed it before
- Photos by email, if that’s easy
- The problem you’ve noticed
- Where the property is
If you are in Thornton Heath and need sand mastic, call 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you’ll get a clear quote before any work starts.
What we are called out for in Thornton Heath
Decorating can disturb tired mastic. Many people find it crumbling when they prepare the windows.
Look out for any of the following:
- A silicone bead on a sash window that spoils the look
- Weathered mastic on the most exposed windows
- Gaps between timber frames and stone or brick
- Wind and rain getting in round a sash window
Rented homes near Thornton Heath station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Questions to ask before booking
- Whether you can choose the colour
- Which sealant they’ll use, and why
- Who turns up on the day
- Whether VAT is included
What sealant work cannot fix
A few problems are outside what sealant work can do:
- Whether work needs listed building consent
- Sashes that rattle, stick or won’t open
- Decayed frames that need repair
Not sure which it is? You can phone 0345 464 0079 or email us and we’ll tell you honestly.
What we seal
- Sash and case windows
- Timber door frames
- Brick reveals
- Period & listed homes
- Tenement windows
- Stone surrounds
Thornton Heath questions
Is Thornton Heath in your area for sand mastic?
Yes, Thornton Heath is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or email us with a few details of the job, and we’ll send you a clear quote.
Is parking an issue for sand mastic in Thornton Heath?
In much of London, parking needs planning: a visitor permit or a bay close to the door helps a lot.
What information do you need?
The location, the problem and the rough size of the job. Photos by email help too.
Can tenants book the work?
Yes, but check with your landlord or agent first. Landlords are often happy for the work to be arranged.
Can you work on commercial sites?
Yes. We work in offices, washrooms, hotels and other commercial premises. We can talk about working times when we quote.
Where are you based?
Our base is Crawley, with over 20 years’ experience. We work across South East England, London and Scotland.
Do you work for letting agents?
Yes. We work for homeowners, landlords, letting agents, businesses and hotels in Thornton Heath.
Can you seal over the old sealant?
No, it won’t last. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Why deal with it now?
New mastic over crumbling mastic won’t hold. Raking out and preparing the joint gives it a sound base so the new mastic stays put. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. You’ll know the price before we begin.
What you get with us
- 180+ five-star Google reviews
- We never seal over old sealant
- We leave the area clean and tidy
- ARBOMaster approved applicator
See how sealant jobs are priced and our reviews.
Sand mastic in Thornton Heath: local notes
Compared with the north and west, the South East gets less rain, 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 check that before you book.
As a London address, Thornton Heath can be tricky for parking: let us know about parking bays, permits or a driveway. If you look after a building such as Winterbourne Junior Girls' School, its window and door frames need their mastic kept sound, just like a home’s.
Thornton Heath is about 7 miles south of London, in Greater London. We carry out sand mastic for homes and businesses in Thornton Heath. Thornton Heath is one of 764 places in Greater London we cover for sand mastic. You can also see our page for London, about 7 miles away.
Work in CR7, SW16 and SE25 works the same way as everywhere else we cover. That includes homes and businesses on Ena Road, Elm Road and Mayo Road and the roads around them. Being close to the A23 and A212, Thornton Heath is simple for us to get to. Neighbouring places we cover for sand mastic include Norbury (1 mile north), Pollards Hill (1 mile north), Mitcham (2 miles west), Hackbridge (2 miles west) and Eastfields (2 miles west). Within a short drive, we also cover London (7 miles north), City of Westminster (8 miles north), Marylebone (8 miles north), Kensington (8 miles north-west), St Pancras (9 miles north) and Shoreditch (9 miles north).
Near you in Thornton Heath
In Thornton Heath, that means homes and buildings near The Archbishop Lanfranc School, Prince George pub and Grangewood Park, among other places. Thornton Heath has its own railway station: Thornton Heath station. Other landmarks nearby include Centrale Croydon (1.7 miles south) and Croydon University Hospital (0.7 miles south). For a walk, there’s Biggin Wood and Duppas Hill.
How it works
Before we leave, we go over the finished joints with you. The work normally takes anything from a few hours to a full day, depending on how many windows, depending on how much there is to do. In Thornton Heath, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We check the window surrounds and agree which joints need renewing.
- We rake out the old mastic and clean the joint.
- Deep voids are packed so the mastic is the right thickness.
- 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.
How to prepare
- Tell us about any previous sealing or DIY attempts
- Let us know about parking restrictions
- Mention any sign-in or site rules at work premises
How to get a quote
To get a quote, call 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. We’ll send you a clear quote before any work starts.
Related advice
Different surfaces, different methods
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We work on single windows or whole elevations.
Period and listed homes
Many older homes were built with sand mastic round the windows. On listed buildings, check with your planning authority first.