Greater London · England
External & façade joints in Chelsea, Greater London
External mastic across Chelsea and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- Panel joints letting water in
- Damp patches traced to an open external joint
- Movement joints with cracked, split or missing sealant
Chelsea: your questions answered
Can parking be tricky for a visit in Chelsea?
Parking in Chelsea, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
I let a flat near London Victoria station. Can you help?
Yes. We work for landlords and agents as well as householders, and several properties can go on one quote. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
How long will you be here?
Typically it takes anything from a few hours to several days, depending on the building. Larger jobs naturally take longer, and we’ll say how long yours will take.
Why is there a gap in my brick wall?
Most straight vertical gaps in brickwork are movement joints. It lets the bricks expand without cracking, and it should be sealed with a flexible sealant.
Can you reach joints on upper floors?
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.
Do you do commercial work?
Yes. We have worked for hotels, offices and other businesses, and we are fully insured.
Do you take out the old sealant first?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
What do you need from me for a quote?
A short description and the location, with photos by email if possible. If we need more, we’ll ask.
How we handle external mastic in Chelsea
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. We pick a colour that sits well with the wall. Typical jobs include joints pointed up with cement by mistake and failed sealant between panels on a façade, across joints between brick and frames, concrete & block and façade panels.
In London terraces and converted houses, gutters and walls are often shared with the house next door, so a leaking gutter joint or failed wall joint can affect more than one home. In a converted house in Chelsea, it’s worth checking who is responsible for the outside before booking.
You’re covered for a year from the day we finish. If there’s a problem with it, please call 0345 464 0079 or send us an email.
- Where
- Chelsea (SW3, SW10, SW1X, SW1W)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
More services for Chelsea
Walls and rooflines in Chelsea
London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking. 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.
Homes close to Former Welsh Congregational Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant. Schools such as Oratory Roman Catholic Primary School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing. Rented homes near London Victoria station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Chelsea is about 2 miles south-east of Kensington, in Greater London. Chelsea gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. Chelsea is one of 764 towns and villages in Greater London where we work.
Here we cover the SW3, SW10, SW1X and SW1W postcode area for external mastic. If you need external mastic at a property on Markham Square, Wellington Square and Tedworth Square or a nearby road, we can help. Chelsea is on the B302 and B304, so it’s easy for us to get to with everything needed for external mastic. Other places close to Chelsea include Brompton (1 mile north), South Kensington (1 mile west), Little Chelsea (1 mile south-west), Belgravia (1 mile north-east) and World's End (1 mile south-west). Further out, we also cover London (3 miles east), St Pancras (3 miles north-east), Shoreditch (5 miles north-east), Walthamstow (9 miles north-east), Hoxton (5 miles north-east) and Whitechapel (5 miles north-east).
What’s near Chelsea
Locally, jobs take us to homes and businesses close to Burton’s Court, St Thomas More RC Language College and Markham Arms Public House. Other local landmarks include Natural History Museum Library and Archives (0.7 miles north-west) and Hellenic College of London (0.5 miles north). Chelsea’s nearest station is London Victoria station, roughly 1 mile north-east. Other landmarks nearby include Baynard's Castle (3.2 miles north-east) and Harrods (0.7 miles north). Green spaces nearby include Campden Hill and Battersea Park Lake.
How it works
On the day, there’s very little for you to do. Point us to the joints and we’ll get on with it. The job generally takes a few hours to a few days, depending on the length of joint and the access, including the tidy-up. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Getting ready for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Let us know if you’ve seen damp or leaks
- On commercial sites, let us know about site rules
Get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we will talk you through the work before giving you a price.
Related advice
Keeping the joints in good condition
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Deal with leaking gutters that soak the joints below
- Wash walls gently around the sealant
- Get split or bare joints resealed while the damage is small
- Do not let climbing plants root in the sealant
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Water getting behind cladding or render can go unnoticed for a long time. By the time there’s a damp patch, the damage can be well established.
What we can’t put right
Honest advice matters more to us than a booking, so here’s what sealant cannot fix:
- Damp that isn’t coming from the joint
- Adding movement joints to masonry that has none
- Cracked brickwork or render that needs a builder or plasterer
If you are not sure, just phone 0345 464 0079 or email us and we’ll give you a straight answer before booking.
What we seal
- Joints between brick and frames
- Render & cladding joints
- Brickwork movement joints
- Copings & trims
- Façade panels
- Concrete & block
What affects the quote in Chelsea
We don’t publish a price list, because no two jobs are the same. The quote depends on:
- The number of rooms or windows
- How much old sealant there is and how hard it is to remove
- The type of sealant required
- Any working-time requirements on site
Combining jobs into one visit is usually more efficient than separate visits. We’ll give you a clear quote for the lot.
What to tell us for a quote
You don’t need to know the technical terms. Just tell us:
- Any previous sealing or DIY work
- Any access issues, like height or stairs
- Where the property is
- What’s wrong with the joints now
Asking for a quote is easy: tell us what needs doing and where. A few pictures by email make the job easier to understand, and we’ll come back to you with a quote.
DIY versus a professional finish
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
Work for landlords, hotels and businesses
Failed sealant is one of the commonest items on a check-out report. We can quote for more than one property at once.
Hotels need rooms back in use, so the work can be planned room by room. We’ve worked in hotels as well as homes and businesses.
How the job changes by surface
Concrete and blockwork
Big joints in concrete need careful depth control. Backing rod sized to the joint sets it and keep the sealant to the right depth.
Render joints
Render is weaker at the surface than brick, so a sealant that stretches easily protects the edges. We prime where the product needs it.