Greater London · England
Sand mastic for sash & case windows in Clapham Park, Greater London
Sand mastic across Clapham Park and nearby, with every bit of old sealant taken out first and a one-year guarantee.
- Old cement repairs round a window that have failed
- Crumbling sand mastic round a window
- Draughty sash windows at the surround
Clapham Park: your questions answered
Is parking an issue for sand mastic in Clapham Park?
Parking in Clapham Park, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Can you help a landlord with a rental near Clapham High Street station?
Yes, rental work is part of what we do. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear quote.
What information do you need?
The location, the problem and the rough size of the job. If you can, email a few pictures.
What sealant do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Should I try DIY first?
It depends on the job. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional.
Is sand mastic better than silicone for my windows?
That depends on your windows. On many period windows, sand mastic looks right and suits the building, while modern frames normally get a flexible sealant.
Can you work on commercial sites?
Yes. We can plan bigger jobs in stages.
Will the old sealant be removed?
Yes, every time. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
How we handle sand mastic in Clapham Park
A silicone bead around a sash window can look out of place and doesn’t suit the building. Sand mastic is the traditional choice and we can swap the silicone for it. We work on period & listed homes, timber door frames and tenement windows, and common reasons people get in touch are mastic dropping out of the joint and gaps round a timber door in stone or brick.
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, letting in draughts and water.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Clapham Park (SW4, SW2, SW12)
- Region
- Greater London
- Cover
- One year on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens on the day
Good joint work is mostly preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. In total, it normally takes a few hours per window, depending on the condition of the joints. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Clapham Park. A visitor permit or a nearby bay makes the visit run more smoothly.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic is not too thick.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Before we arrive
- Let us know if you’ve seen damp or leaks
- Keep pets and children clear of the area while we work
- Move anything stored near the joints
Getting a quote
If you’re in Clapham Park and need sand mastic, call 0345 464 0079 or send us an email. Tell us what the problem is and where, and you’ll get a clear quote before we start.
Advice
For landlords and businesses
Whether it’s one flat or a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
In hotels, rooms out of use cost money, so the work can be planned room by room. We’ve worked in hotels as well as homes and businesses.
Places near Clapham Park
What else we do in Clapham Park
Surface by surface
Stone surrounds
We take care not to mark the stone when the old mastic comes out.
Brick reveals
Sand mastic is also used where timber frames meet brick. It gives a traditional finish.
Windows and doors in Clapham Park
Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Carlyle's House (about 2.6 miles north-west) nearby, there’s older building stock in the area around Clapham Park as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
As a London address, Clapham Park can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. Letting a property close to Clapham High Street station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about.
Clapham Park is about 1 mile south-west of Stockwell, in Greater London. Our applicators cover sand mastic for homes and businesses in Clapham Park. Clapham Park is one of 764 places in Greater London where we work for sand mastic.
Here we cover the SW4, SW2 and SW12 postcode area for sand mastic. Whether your property is on Lynn Road, West Road and Elms Road or a nearby road, we can help. If you are just outside Clapham Park, we cover Grange Mills (1 mile south-west), Hyde farm estate (1 mile south), Brixton (1 mile east), Clapham (1 mile north) and Balham (1 mile south-west). Larger places within reach include London (4 miles north-east), City of Westminster (4 miles north), Marylebone (4 miles north), Kensington (4 miles north-west), St Pancras (5 miles north) and Shoreditch (6 miles north-east).
Local landmarks in Clapham Park
Typical jobs here are in homes near Harris Academy Clapham, The Family School and Ye Olde Windmill Public House, among other places. Clapham Park’s nearest station is Clapham High Street station, about 0.8 miles north. Nearby you’ll also find St James' Hospital (1.4 miles south-west) and Soseki Museum (0.9 miles north-west). The countryside around Clapham Park includes Battersea Park Lake and Centre for Wildlife Gardening.
When it isn’t the sealant
In fairness, there are a few things sealant won’t fix:
- Masonry that needs repairing
- Whether work needs listed building consent
- Decayed frames that need repair
If you are not sure, just phone 0345 464 0079 or drop us an email and we’ll give you a straight answer.
Joints and surfaces we work on
- Timber door frames
- Tenement windows
- Stone surrounds
- Sash and case windows
- Brick reveals
- Period & listed homes
Common problems we fix in Clapham Park
Rain on the window surround works into any crack and pushes it out. Exposed elevations usually fail first.
If you can see any of these, it’s time to have the joints looked at:
- Crumbling sand mastic round a window
- Patchy fillers round a sash window
- A silicone bead on a sash window that spoils the look
- Mastic that needs renewing before redecorating
For site and facilities teams at buildings such as Glenbrook Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
What your quote should include
- The length of the guarantee
- Who turns up on the day
- What happens if they find a problem under the old sealant
- What the quote includes, VAT included or not
How we quote for sand mastic
The quote reflects the job in front of us. We look at:
- How many areas need sealing
- The size of the job
- When we can work, for business premises
- How easy the joints are to reach
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
What we need to know
Photos help, but a description is a good start. Try to tell us:
- Pictures of the joints, sent by email
- What’s wrong with the joints now
- Any previous sealing or DIY work
- The rough size of the job
We quote each job on its own, so the first step is telling us about yours. Simply call 0345 464 0079 or email us and describe the job.
Looking after it afterwards
To keep the joints looking good and working properly:
- Renew mastic before redecorating the windows
- Do not run silicone over sand mastic
- Look over the window mastic once a year
- Do not paint over the new mastic
Avoid sealing over the mastic with silicone. If anything cracks, get it looked at rather than patching it.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.