Greater London · England
External Mastic in South Bank
We cover South Bank for sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly.
- Joints pointed up with cement by mistake
- Sealant pulling away from one side of the joint
- Old sealant gone brittle and cracked
How we handle external mastic in South Bank
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. We pick a colour that sits well with the wall so the line blends in. We work on render & cladding joints, copings & trims and joints between brick and frames, and common reasons people get in touch are joints with sealant missing in places and plants rooting in failed movement joints.
Outside work in London starts with access: side passages, upper floors and where to park. For a home in South Bank, tell us how high the joints are and how to reach the back of the building.
The work is covered for a year after we finish. If there’s a problem with it, please call 0345 464 0079 or send us an email.
- Location
- South Bank (SE1, WC2E, WC2N)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Why deal with it now?
A failed movement joint lets water into the wall, behind render and cladding. Dealing with it early keeps the repair to the joint, rather than the wall around it. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in South Bank, the repair is bigger than the sealant job would have been.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, along with when we can work on site. Ask us for a quote and we will go through it with you.
Why book with us
- Anti-fungal silicone where joints get wet
- White, clear, grey or another colour, product permitting
- More than 20 years in sealant work
- Colour agreed with you before work begins
Read our cost guide or customer reviews.
What affects the cost of external mastic
Your quote is based on your job. We take into account:
- Any mould that needs treating
- Whether the work is at height
- Which sealant suits the joint
- The number of rooms or windows
No two jobs are quite the same, 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.
Asking for a quote
When you contact us, these details help:
- Any previous sealing or DIY work
- Any access issues, like height or stairs
- Where the job is, and your postcode
- How many joints, rooms or windows are involved
We don’t publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or email us.
How the visit works
We work through the job in order: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours to a few days, depending on the length of joint and the access. In South Bank, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- First we look over the joints with you, agree which to renew and talk through access.
- The old mastic and anything lodged in the joint is removed.
- The joint faces are cleaned and primed where the sealant needs it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Preparing for the visit
- Mention any parking rules near the property
- Try not to wet indoor joints just before the visit
- For business premises, tell us about site rules or sign-in
How to get a quote
Asking for a quote is easy: tell us what needs doing and where and its rough size. Photos by email help us understand the job, and we will take it from there.
Related advice
Also near South Bank
What else we do in South Bank
Can I do it myself?
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, then guaranteed for a year.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
What we’re called out for in South Bank
Using the wrong sealant is another common reason. A high-modulus or general-purpose sealant can be too rigid for a busy joint, so it pulls away from the edges.
Most people get in touch when they notice one of these:
- Gaps where render, brick and frames meet
- Rigid filler in a joint that should flex
- Water getting into walls through failed joints
- Sealant that has lost its bond to the brick or render
As a London address, South Bank can be tricky for parking: let us know about parking bays, permits or a driveway.
What to look for in a quote
- Who turns up on the day
- What the quote includes, VAT included or not
- How the surfaces are prepared before sealing
- Whether they’re fully insured
Keeping the joints in good condition
A little care helps the new joints last. We recommend:
- Never let anyone fill a movement joint with mortar
- Keep high-pressure jets off the joints
- Keep soil, plants and ivy away from the joints
- Fix overflowing gutters above sealed joints
Keep the joints clear of soil, plants and climbing growth. Anything that holds water against the joint wears it out sooner.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage, all bigger jobs than a reseal.
What we can’t put right
We’ll always be straight with you, so here’s what new sealant will not do:
- Render that is blown, hollow or coming away
- Rising or penetrating damp from elsewhere in the wall
- Movement that’s more than a sealant joint can take
If you’re not sure, just phone 0345 464 0079 or send us an email and we’ll give you a straight answer.
What we seal
- Façade panels
- Copings & trims
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
- Render & cladding joints
External mastic in South Bank: 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 terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts.
Managing a site like Oasis Academy Johanna? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Rented homes near London Waterloo station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets.
South Bank is about 1 mile west of London, in Greater London. Every kind of property in South Bank can book us for external mastic, old or new, large or small. Every job comes with our 12-month guarantee. Our area takes in 764 places across Greater London, large and small.
We work across SE1, WC2E and WC2N for external mastic. That includes homes and businesses on York Road, Spur Road and Lower Road and the roads around them. South Bank is on the A301 and A302, so it’s easy for us to get to with everything needed for external mastic. We also cover the places around South Bank: Waterloo (1 mile south-east), Adelphi (1 mile north-west), Charing Cross (1 mile north-west), Temple (1 mile north-east) and Aldwych (1 mile north). We also work in nearby towns such as Kensington (4 miles west), Walthamstow (7 miles north-east), Hampstead (4 miles north-west), Ruislip (14 miles west), Stockwell (3 miles south) and Orpington (13 miles south-east).
What’s near South Bank
Typical jobs here are in homes near Jubilee Gardens, The Hole In The Wall pub and The BFI Reuben Library. You will also find St Andrew's and St John's Church of England Primary School (less than half a mile east) and London Nautical School (under half a mile north-east). There’s a railway station in South Bank itself: London Waterloo station. Other landmarks nearby include Florence Nightingale Museum (less than half a mile south) and Royal Waterloo Hospital for Children and Women (within half a mile north-east). Not far away are Barnsbury Wood and St. James's Park Lake.
Your questions about external mastic in South Bank
Do you work for landlords with property near London Waterloo station?
Yes, we work for landlords and letting agents. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear quote.
Is parking an issue for external mastic in South Bank?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
How often do external joints need resealing?
It depends on the exposure, the movement and the product. Sealant is a maintenance item, so check the joints once a year and renew it when it starts to fail.
Why do you put foam in the joint first?
That is backing rod, a closed-cell foam. It keeps the sealant at the right depth and bonded to the sides only so it can flex with the joint.
Do the sealants smell?
That depends on the sealant. Some smell for a while, some hardly at all, and any smell fades as they cure.
Should I try DIY first?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Can you match the colour of my brickwork?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We pick the one that suits your wall best.
Can I add another job to the visit?
Of course. Combining jobs makes good use of the visit.