Greater London · England
External Mastic in Clapham Junction
Sealing brickwork movement joints, render, cladding and façade joints in Clapham Junction, with a 12-month guarantee on every job. Call for a quick quote.
- Joints pointed up with cement by mistake
- Panel joints letting water in
- Gaps where render, brick and frames meet
Aftercare tips
No joint lasts for ever, but care makes a real difference. A few tips:
- Act on the first splits you see
- Look over the joints every year, ideally after winter
- Never let anyone fill a movement joint with mortar
- Point out the joints to other trades
Make sure anyone working on the wall later knows where the movement joints are. They should be kept open and resealed, not filled.
Gaps, plants or missing sealant in a joint are worth getting looked at. Earlier resealing means a smaller job and a better result.
External mastic in Clapham Junction, done properly
Low-level joints can generally be done from the ground. For joints higher up, give us some details of the building and we’ll confirm what’s needed to reach them safely. If you have sealant pulling away from one side of the joint and water getting into walls through failed joints, we can help, whatever the surface.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Clapham Junction, tell us how high the joints are and how to reach the back of the building.
All our work comes with our 12-month guarantee.
- Where
- Clapham Junction (SW11, SW18, SW4)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What we do, step by step
There isn’t much for you to do on the day. Point us to the joints and we will get on with it. The work itself takes anything from a few hours to several days, depending on the building. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Preparing for the visit
- Tell us about any previous sealing or DIY attempts
- Let us know if you’ve seen damp or leaks
- Mention any tricky access
Ask for a quote
To get a quote, ring 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. We’ll give you a clear price before any work starts.
Related advice
Honest limits
It helps to know what we can’t do:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Subsidence or other structural problems
- Cracks in the bricks or render themselves, away from the joints
If you are not sure, just ring 0345 464 0079 or email us and we will give you a straight answer before booking.
Joints and surfaces we work on
- Concrete & block
- Joints between brick and frames
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Façade panels
For landlords and businesses
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
If you manage several properties in or around Clapham Junction, several properties can go on one quote. Just tell us the addresses and what each one needs, and pictures by email help.
What affects the quote in Clapham Junction
We do not publish a price list, because jobs vary so much. The quote depends on:
- How many areas need sealing
- How easy the joints are to reach
- The amount of work
- How much old sealant there is and how hard it is to remove
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
What to tell us for a quote
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- A few pictures by email, if you can
- The address or postcode of the job
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
Need a quote? Please ring 0345 464 0079 or drop us an email with a few details. We’ll explain what we’d do and give you a clear quote before we start.
Outside joints around Clapham Junction
Historic houses like Carlyle's House (about 1.4 miles north) are a reminder that the area around Clapham Junction has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking.
For an older house near a landmark such as Clapham Welsh Presbyterian Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Rented homes near Clapham Junction station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Clapham Junction is about 3 miles south-east of Kensington, in Greater London. Across the SW11 area, we cover external mastic for homes and businesses. We cover 764 towns and villages across Greater London, from the larger towns to small villages.
All of SW11, SW18 and SW4 is within our area for external mastic, from the main roads to the quietest streets. Whether your property is on York Road, Este Road and Home Road or a nearby road, our applicators can take on the job. Main roads around Clapham Junction include the A3207, so getting to you is simple. We also cover Battersea (1 mile south-east), Sands End (1 mile north-west), Chelsea Harbour (1 mile north-west), Wandsworth (1 mile south-west) and Clapham (1 mile east). We also work in nearby towns such as London (4 miles north-east), City of Westminster (4 miles north), Marylebone (4 miles north), Kensington (3 miles north-west), St Pancras (5 miles north-east) and Shoreditch (6 miles north-east).
Around Clapham Junction
Around Clapham Junction, our work takes us to homes and buildings near Imperial Park, The Falcon pub and Thames Christian College and the streets around them. Clapham Junction has its own railway station: Clapham Junction station. Well-known places in the area include Baynard's Castle (4.4 miles north-east) and Battersea General Hospital (0.8 miles north). Open spaces near Clapham Junction include Battersea Park Lake and Wandle Meadow Nature Park.
Also near Clapham Junction
What else we do in Clapham Junction
FAQs for Clapham Junction
Do you work for landlords with property near Clapham Junction station?
Yes, we work for letting agents and landlords. You can call 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Can parking be tricky for a visit in Clapham Junction?
Parking in Clapham Junction, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
Will the old sealant be removed?
Always. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Do you have insurance?
Yes, we’re fully insured.
How long will you be here?
Typically it takes anything from a few hours to several days, depending on the building. Bigger jobs take longer, and we’ll tell you how long to expect.
Is the work guaranteed?
Yes: twelve months. If there’s a problem with our work in that time, tell us and we’ll put it right.
How do you reach high-level joints?
It depends on the height and the site. Ground-floor joints are simple; for higher work, tell us about the building and we’ll confirm what’s needed.
How long before the joint can be used?
Many sealants skin over quickly but take longer to cure fully. We will tell you how long to leave the joint before we leave.
Why it’s worth doing now in Clapham Junction
Done well, a resealed joint is a neat, straight line that suits the wall. A rushed bead with no backing looks untidy and doesn’t last so it’s worth doing right. In a flat in Clapham Junction, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all play a part.
What you get with us
- One-year guarantee on every job
- A choice of colours where the product allows
- Over 20 years’ experience
- Colour picked to suit the job
See our cost guide and what customers say.
When to call us in Clapham Junction
Sunlight, wet weather and frost wear exterior sealant down. In time it goes hard, crazes on the surface and stops stretching, so the next time the wall moves, it splits or pulls away.
Any of these means the joints need attention:
- Sealant pulling away from one side of the joint
- Plants rooting in failed movement joints
- Rigid filler in a joint that should flex
- Leaking joints around cladding and façade panels
Schools such as Christ Church CofE Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Comparing quotes
- When the joint can take water or movement
- How the colour is chosen
- Are they insured?
- Whether all the old sealant comes out first