Greater London · England
External & façade joints in Westminster, Greater London
Professional external mastic in and around Westminster, with every bit of old sealant taken out first and a 12-month guarantee.
- Failed sealant between panels on a façade
- Sealant pulling away from one side of the joint
- Weathered mastic that no longer stretches
How the visit works
We work through the job in order: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours for a handful of joints, longer for a whole elevation, and the area is left clean. In Westminster, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- The old mastic and anything lodged in the joint is removed.
- Both sides are cleaned back to sound material and primed if needed.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
How to prepare
- Tell us about any previous sealing or DIY attempts
- Keep children and pets away from the work area
- Clear items away from the joints we are working on
How to get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and email pictures if that is easy.
Related advice
External mastic in Westminster, done properly
A movement joint is only as good as its depth. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, so it bonds to the two sides only and can stretch. If you have rigid filler in a joint that should flex and rain getting behind render or cladding at a joint, we can put it right, whatever the surface.
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 Westminster, it’s worth checking who is responsible for the outside before booking.
Whatever the size of the job, you get the same 12-month guarantee in Westminster and across Greater London.
- Where
- Westminster (SW1P, W1J, SW1V)
- Region
- Greater London
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
What affects the cost of external mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- The size of the job
- How many areas need sealing
- Whether old sealant or filler has to be cut out
- Access and height
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please phone 0345 464 0079 or drop us an email and we will talk you through it.
Asking for a quote
Before you ask for a quote, have a think about:
- Roughly how big the job is
- Where the job is, and your postcode
- Any access issues, like height or stairs
- If someone has resealed it before
Quotes start with a quick conversation. Describe the problem, the location and the size of the job. When it suits you, phone 0345 464 0079 or send us an email.
Common problems we fix in Westminster
Weeds, moss and debris in a joint are a sign the sealant has gone. Dirt and roots then trap moisture in the joint.
Common reasons people contact us include:
- Movement joints with cracked, split or missing sealant
- Cracked joints where brick meets render or frames
- Leaking joints around cladding and façade panels
- Rain getting behind render or cladding at a joint
For an older house near a landmark such as Christ Church, older walls, gutters and the joints where extensions meet them need a flexible sealant.
What to look for in a quote
- What the cure time is
- Are they insured?
- What product goes in the joint
- How long the guarantee is
DIY versus a professional finish
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.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Westminster questions
Is Westminster in your area for external mastic?
Yes, Westminster is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or drop us an email and tell us what needs doing.
Is parking an issue for external mastic in Westminster?
Parking in Westminster, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
I rent my home. Can I book you?
We are happy to deal with the tenant, landlord or agent. Get your landlord’s agreement first.
Will there be a smell?
Sometimes, a little. Any smell clears as the sealant cures, and ventilation helps.
What’s an expansion joint in brickwork?
Brickwork, render and cladding all move a little, so long walls have planned gaps to take that movement. The gap is sealed with a flexible sealant over backing rod.
How long does the job take?
As a guide, most jobs take a few hours for a handful of joints, longer for a whole elevation. Bigger jobs take longer, and we’ll tell you how long to expect.
Do you work for letting agents?
Yes. We work for householders, landlords, letting agents, businesses and hotels across Greater London.
Is there a guarantee?
Yes. All our work carries a 12-month guarantee.
For landlords and businesses
Landlords and letting agents in Westminster can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
Hotels need rooms back in use, so the work can be planned room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
What external mastic looks like in Westminster
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you let a flat or house near London Victoria station, outside joints that have cracked can let damp into a rental, so check them between lets. Westminster is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Westminster is about 1 mile south-east of City of Westminster, in Greater London. Westminster gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. 764 places in Greater London are on our list.
Work in SW1P, W1J and SW1V works the same way as everywhere else we cover. Whether your property is on Eaton Lane, Wilton Road and Castle Lane or anywhere close by, we can help. Westminster sits on or near the A4 and A202, so getting to you is simple. Other places close to Westminster include Millbank (1 mile north), Victoria (1 mile south-west), Pimlico (1 mile south), Vauxhall (1 mile south-east) and Lambeth (1 mile south-east). Larger places within reach include Kensington (3 miles west), Shoreditch (3 miles north-east), Walthamstow (8 miles north-east), Hoxton (3 miles north-east), Whitechapel (3 miles north-east) and Hampstead (4 miles north-west).
Landmarks near Westminster
Around Westminster, our work takes us to homes and buildings near St Matthew's School, St James's Park and Blewcoat School. You’ll also find London Library (0.6 miles north) and Grafton Arms (under half a mile south). The closest station to Westminster is London Victoria station, roughly 0.6 miles south-west of the centre. Other landmarks nearby include Westminster Hospital (within half a mile east) and The Crime Museum (under half a mile south). The countryside around Westminster includes Barnsbury Wood and St. James's Park Lake.
What the job involves on each surface
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. They’re resealed over backing rod with a low-modulus sealant coloured to suit the wall.
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.
Also in Westminster
When it isn’t the sealant
To be straight with you, some problems need a different trade:
- Structural movement, which needs a surveyor or engineer
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracks in the bricks or render themselves, away from the joints
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think.
Joints and surfaces we work on
- Brickwork movement joints
- Façade panels
- Render & cladding joints
- Copings & trims
- Concrete & block
- Joints between brick and frames