Greater London · England
Sand mastic for sash & case windows in Chislehurst, Greater London
Specialist sand mastic for Chislehurst: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Cracked mastic round a front door frame
- Tired mastic found when preparing windows for paint
- Failed mastic on an exposed elevation
About our sand mastic in Chislehurst
Sand mastic is the traditional way to point the gap between a timber window frame and the stone or brick around it. It’s a mix of sand and a linseed-oil-based binder, applied by hand. On period homes, it looks right where silicone wouldn’t. We work on brick reveals, timber door frames and period & listed homes, and common reasons people get in touch are mastic round period door frames that has failed and gaps where the frame meets the masonry.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. The mastic around them dries out and cracks with age, which is when draughts and damp patches appear in homes in Chislehurst.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Where
- Chislehurst (BR7, BR1, BR2, SE9)
- Region
- Greater London
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What we are called out for in Chislehurst
Timber swells and shrinks with the weather. The movement cracks the mastic little by little.
People generally contact us when they notice one of these:
- Crumbling sand mastic round a window
- Open joints round the window box
- Modern sealant on a period surround
- Cracked mastic round a front door frame
Chislehurst is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Comparing quotes
- Which sealant they’ll use, and why
- What the quote includes, VAT included or not
- How the colour is chosen
- What guarantee comes with the work
What else we do in Chislehurst
Chislehurst: your questions answered
Is Chislehurst in your area for sand mastic?
Yes. Our work covers London and the South East, and Chislehurst is part of that. You can call 0345 464 0079 or drop us an email and tell us what needs doing.
I let a flat near Chislehurst station. Can you help?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or send us an email and tell us about the property, and we’ll give you a clear quote.
Is consent needed for window work on a listed home?
Speak to your local planning authority before work starts. Sand mastic is often favoured as like for like, but they decide.
Is the work guaranteed?
You get our one-year guarantee on every job.
Can you seal over the old sealant?
No, because it fails. We remove every bit of old sealant first, so the new sealant bonds properly.
What does sand mastic cost?
The cost depends on the size of the job, access and how much old sealant has to come out. Call for a quick quote and we will talk you through it.
What exactly is sand mastic?
It’s a mix of sand and a linseed-oil-based binder. It’s built up in the joint by hand and shaped to suit the surround.
How long does sand mastic take?
A typical job takes a few hours per window, depending on the condition of the joints, including preparation and clearing up. Your quote will say how long we expect yours to take.
Keeping the joints in good condition
Good habits help new joints last longer. Our tips:
- Check with your local planning authority if your home is listed
- Avoid heavy scraping on the mastic joint
- Sort the mastic before the decorators arrive
- Check the mastic when you check the paintwork
Keep gutters and sills clear so water runs away from the surround. Constant wetting wears the mastic faster.
Small cracks are a sign the mastic is ageing. Renewing it then is simpler than waiting until it falls out.
What affects the quote in Chislehurst
The price is agreed before any work begins. It’s based on:
- How many areas need sealing
- Whether the work is at height
- The type of sealant required
- The size of the job
There are no prices on our website, because the cost depends so much on the job itself. For a quick quote, please phone 0345 464 0079 or email us.
Asking for a quote
When you call or email, these details help:
- Any previous sealing or DIY work
- Pictures of the joints, sent by email
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it’s a home or a business
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will talk you through what we’d do. Whenever you are ready, ring 0345 464 0079 or send us an email.
Chislehurst homes and the weather
Historic houses like Bromley Palace (about 2 miles south-west) are a reminder that the area around Chislehurst 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. In a converted house or block, who looks after the windows depends on the lease, so check that before you book.
Rented homes near Chislehurst station change hands often, and older sash windows in a rental need their mastic kept sound to keep the weather out. In the older streets around Parish Church The Annunciation Of Blessed Virgin Mary, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Chislehurst is about 3 miles north-west of Orpington, in Greater London. Across the BR7 area, we cover sand mastic for homes and businesses. Across Greater London, we cover 764 places, and Chislehurst is one of them. For nearby work, see our London page (9 miles or so).
Work in BR7, BR1, BR2 and SE9 is quoted and booked the same way as anywhere else. That includes homes and businesses on Chislehurst High Street, Sanderson Square and Wilderness Road and the roads around them. Chislehurst sits on or near the A208 and B264, which makes travel easy. We also cover Elmstead (1 mile west), Foxbury (1 mile east), Bickley (1 mile south-west), Widmore (1 mile south-west) and Coldharbour (1 mile north-west). Within a short drive, we also cover London (9 miles north-west), City of Westminster (12 miles north-west), Marylebone (12 miles north-west), Kensington (13 miles north-west), St Pancras (11 miles north-west) and Shoreditch (10 miles north-west).
What’s near Chislehurst
We work in homes and buildings around The Queens Head pub, Coopers School and Chislehurst Common. Chislehurst’s nearest station is Chislehurst station, roughly 0.7 miles south-west of the centre. Well-known places in the area include The Glades (2.2 miles west) and Queen Mary's Hospital (1.6 miles east). Not far away are The Tarn and Summer Hill.
How the job changes by surface
Stone surrounds
We take care not to mark the stone while raking out the old mastic.
Tenement and terrace windows
Tenements and terraces often have many sash windows with ageing mastic. We work on single windows or whole elevations.
Why act early in Chislehurst
A silicone bead can be quicker, but it can look wrong on a period surround. Sand mastic is the traditional material and blends with the stone or brick. In London conversions, one flat’s bathroom is often above another flat’s ceiling, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
Every job is a little different, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all make a difference, and we will explain the quote if you ask.
Why us?
- Approved under the ARBOMaster scheme
- Fully insured
- Sanitary silicone with an anti-fungal additive in wet areas
- Rated 4.9 stars on Google
Take a look at what affects the cost and customer reviews.
Landlords, agents and businesses in Chislehurst
Housing providers, facilities teams and property managers book us too in Chislehurst and across Greater London. We can quote a run of properties together.
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements and we’ll give you a quote.
How the visit works
Before we leave, we go over the finished joints with you. The work normally takes a few hours per window, depending on the condition of the joints, depending on the size of the job. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Chislehurst. A visitor permit or a nearby bay makes the visit run more smoothly.
- We look at the surrounds with you and agree the joints to renew.
- Old mastic and any loose material are raked out.
- 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.
Getting ready for the visit
- Mention any sign-in or site rules at work premises
- Keep pets and children clear of the area while we work
- Mention if the joints have been sealed before
Get a quote
To get a quote, call 0345 464 0079 or email us with the location and a short description of the problem. We’ll send you a clear quote before any work starts.