Greater London · England
External & façade joints in Knightsbridge, Greater London
Movement joints in Knightsbridge need attention? We remove the old material, prepare the joints and seal them properly, and the work is guaranteed for a year.
- Water getting into walls through failed joints
- Cracked joints where brick meets render or frames
- Weathered mastic that no longer stretches
When something else is needed
To be straight with you, some problems need a different trade:
- Walls that need new movement joints cut into them
- Render that’s blown, hollow or coming away
- Cracked brickwork or render that needs a builder or plasterer
If in doubt, call 0345 464 0079 or email us and we will say what we think.
Where we work in Knightsbridge
- Concrete & block
- Copings & trims
- Brickwork movement joints
- Render & cladding joints
- Façade panels
- Joints between brick and frames
About our external mastic in Knightsbridge
A movement joint is only as good as its depth. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, so it bonds to the two sides only and can stretch. We’re often asked to deal with movement joints filled with mortar instead of sealant and failed seals between different materials, on joints between brick and frames, brickwork movement joints and concrete & block.
Outside work in London starts with access: side passages, upper floors and where to park. For a home in Knightsbridge, tell us how high the joints are and how to reach the back of the building.
A 12-month guarantee comes as standard.
- Location
- Knightsbridge (SW1X, SW3, W1K)
- Wider area
- Greater London
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
How it works
When we get to you, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. Most jobs then take a few hours to a few days, depending on the length of joint and the access. In Knightsbridge, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- For business premises, tell us about site rules or sign-in
- Tell us about access, such as stairs, a lift or high-level joints
- Let us know about parking restrictions
Ask for a quote
If you are in Knightsbridge and need external mastic, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you’ll get a clear quote before work begins.
Advice
Why act early in Knightsbridge
Mortar or ordinary filler might look like a quick way to close an open joint, but it stops the joint moving. The wall then cracks somewhere else. A flexible sealant over backing rod is what the joint needs. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Doing several joints on one visit normally makes better use of the time than several visits. You will get one clear quote for the whole job.
Why us?
- Arbo and Everbuild products
- Homes, businesses and hotels
- Sealant colour chosen to suit
- Old sealant always removed completely
See what affects the cost or our reviews.
Different surfaces, different methods
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. We reseal them with a low-modulus sealant over backing rod.
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. We cut out the old sealant and reseal with a product suited to both surfaces.
What we’re called out for in Knightsbridge
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it cannot stretch and tears as soon as the joint widens.
Most people get in touch when they notice something like this:
- Sealant pulling away from one side of the joint
- Panel joints letting water in
- Failed seals between different materials
- Rigid filler in a joint that should flex
If you let a flat or house near London Victoria station, split movement joints are easy to miss on a rental until damp shows inside.
What your quote should include
- When the joint can take water or movement
- Is VAT in the price?
- What guarantee comes with the work
- Whether all the old sealant comes out first
Your questions about external mastic in Knightsbridge
I let a flat near London Victoria station. Can you help?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before any work starts.
Is Knightsbridge in your area for external mastic?
Yes. We work across London and the South East, and Knightsbridge is part of that. You can ring 0345 464 0079 or drop us an email and tell us what needs doing.
Is there a guarantee?
Yes, for a year. If anything isn’t right with the work within the year, let us know and we will sort it.
Why do you put foam in the joint first?
The foam is closed-cell backing rod. It stops the sealant going in too deep and bonding to three sides.
Do I need to be at home?
That depends on where the joints are. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
Are you an approved applicator?
Yes. We hold ARBOMaster approved applicator status and we’re fully insured too.
Do you remove the old sealant?
Yes, every time. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
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 reseal when it splits.
External mastic in Knightsbridge: local notes
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. With historic houses such as Apsley House (about 0.5 miles east) nearby, there’s older building stock in the area around Knightsbridge as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
For an older house near a landmark such as Deutsche Evangelische Christuskirche, older walls, gutters and the joints where extensions meet them need a flexible sealant. As a London address, Knightsbridge can be tricky for parking: let us know about parking bays, permits or a driveway.
Knightsbridge is about 1 mile north of Brompton, in Greater London. For external mastic in and around Knightsbridge, it’s easy to get a quote: please call 0345 464 0079 or send us an email. We cover Greater London from our Crawley base. Knightsbridge is one of 764 towns and villages in Greater London where we work.
We work across SW1X, SW3 and W1K for external mastic. If you need external mastic at a property on Hans Road, Park Lane and Cadogan Lane or anywhere close by, our applicators can take on the job. Knightsbridge sits on or near the A315 and A4202, so getting to you is simple. Close by, we work in Tyburn (1 mile north), Mayfair (1 mile north-east), Hyde Park Estate (1 mile north), Connaught Village (1 mile north) and City of Westminster (1 mile north-east). Further out, we also cover London (3 miles east), St Pancras (3 miles north-east), Shoreditch (4 miles north-east), Walthamstow (8 miles north-east), Hoxton (4 miles north-east) and Whitechapel (4 miles east).
Near you in Knightsbridge
Locally, jobs take us to homes and businesses close to Saint Thomas More Language College, St Joseph's Catholic Primary School and Paxtons Head pub, among other places. Nearby too are Natural History Museum Library and Archives (0.7 miles south-west) and Royal Parks of London (0.5 miles north). The closest station to Knightsbridge is London Victoria station, about 0.9 miles south-east of the centre. Other landmarks nearby include London Lock Hospital (0.6 miles east) and Westminster Synagogue Czech Memorial Scrolls Museum (less than half a mile west). Open spaces near Knightsbridge include Campden Hill and Greville Place nature reserve.
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. A few tips:
- Point out the joints to other trades
- Clear growth from the base of walls and joints
- Deal with leaking gutters that soak the joints below
- Make sure movement joints aren’t pointed over
Keep pressure washers away from the sealant. A strong jet can damage the edges of the bead and let water in behind.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
Also near Knightsbridge
What else we do in Knightsbridge
What affects the cost of external mastic
We do not publish a price list, because no two jobs are the same. What we look at:
- The number of rooms or windows
- Which sealant suits the joint
- How easy the joints are to reach
- The amount of work
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote.
What to tell us for a quote
There’s no need for technical detail. It helps if you can tell us:
- Whether it’s a home or a business
- Access, such as stairs, a lift or height
- What the problem is, such as mould, gaps, leaks or cracking
- Any previous sealing or DIY work
To get a quote, call 0345 464 0079 or drop us an email with the location and a short description of the problem. You’ll have a clear quote before we start.