Greater London · England
Marylebone External Mastic
Our applicators work in Marylebone on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Joints pointed up with cement by mistake
- Movement joints with cracked, split or missing sealant
- Hard, crazed mastic that has stopped moving
Marylebone: your questions answered
Is parking an issue for external mastic in Marylebone?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Do you cover Marylebone for external mastic?
Yes. Our work covers London and the South East, and Marylebone is part of that. You can call 0345 464 0079 or drop us an email and tell us what needs doing, and we’ll give you a clear quote.
How do you reach high-level joints?
It depends on the height and the site. Low-level joints are straightforward; for higher work, tell us about the building and we’ll confirm what’s needed.
Can you seal joints between two different materials?
Yes. Materials like render, brick, metal and uPVC all move differently, so a flexible sealant is needed where they meet. The sealant is matched to both sides.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done.
What does external mastic cost?
We don’t publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. You’ll get a clear quote before any work starts.
Can you seal over the old sealant?
No. We remove every bit of old sealant first.
Do you do commercial work?
Yes. We work in offices, washrooms, hotels and other commercial premises. We can talk about working times when we quote.
How we handle external mastic in Marylebone
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We take the old material out and do it properly. We are often asked to deal with weeds or debris growing in open joints and old sealant gone brittle and cracked, on copings & trims, concrete & block and render & cladding joints.
London’s terraces and conversions often share walls, gutters and downpipes with their neighbours, so a leaking gutter joint or failed wall joint can affect more than one home. For a flat in Marylebone, check the lease for who looks after the outside.
We guarantee the work for a year. If something isn’t right with it in that time, tell us and we’ll put it right.
- Location
- Marylebone (W1U, W1T, W1K)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Landlords, agents and businesses in Marylebone
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together.
For anyone letting property in or around Marylebone, jobs at different addresses can go on one quote. Send us the addresses and the work at each.
DIY versus a professional finish
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
Also near Marylebone
More services for Marylebone
What external mastic looks like in Marylebone
With historic houses such as Handel Hendrix House (about 0.3 miles south) nearby, there’s older building stock in the area around Marylebone as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
As a London address, Marylebone can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. Homes close to Russian chapel on Welbeck Street include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
Marylebone is about 3 miles north-west of London, in Greater London. If you need external mastic in Marylebone, it’s easy to get a quote: please ring 0345 464 0079 or send us an email. We’re based in Crawley and cover Greater London, Marylebone included. Our Greater London coverage runs to 764 places, and Marylebone is one of them.
Every address in W1U, W1T and W1K is within our area for external mastic. If you need external mastic at a property on Park Lane, Duck Lane and Bruton Lane or a nearby road, we can help. Marylebone sits on or near the A400 and A401. Nearby, we also carry out external mastic in City of Westminster (1 mile south-west), Mayfair (1 mile south), Fitzrovia (1 mile north-east), Burlington Estate (1 mile south-east) and Soho (1 mile south-east). Larger places within reach include London (3 miles south-east), Kensington (3 miles south-west), Shoreditch (3 miles east), Walthamstow (7 miles north-east), Hoxton (3 miles north-east) and Whitechapel (3 miles east). Marylebone is one of the larger places we cover in Greater London.
Landmarks near Marylebone
Locally, jobs take us to homes and businesses close to St Anne's Churchyard, The St Marylebone CofE School and Royal Society of Medicine Library and the streets around them. Nearby too are The St Marylebone CofE School (less than half a mile north-west) and The Phoenix pub (under half a mile south-east). There’s a railway station in Marylebone itself: Bond Street station. Other landmarks nearby include Montfichet's Tower (2 miles east) and Twist Museum (within half a mile south-east). For a walk, there’s Adelaide Nature Reserve and St. James's Park Lake.
Keeping the joints in good condition
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Have failed joints looked at early
- Look over the joints every year, ideally after winter
- Wash walls gently around the sealant
- Never let anyone fill a movement joint with mortar
Follow the cure time we give you before the joint is knocked or disturbed. The surface skins over quickly, but full cure takes longer.
Small splits are the time to act. At that stage it’s a simple cut out and reseal.
How the visit works
When we get to you, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. Most jobs then take anything from a few hours to several days, depending on the building. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Marylebone. A visitor permit or a nearby bay makes the visit run more smoothly.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- Old sealant and any debris are cut and raked out.
- Both sides are cleaned back to sound material and primed if needed.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Getting ready for the visit
- For indoor joints, keep the area dry beforehand if you can
- Mention any leaks or damp you’ve noticed
- Mention if the joints have been sealed before
Ask for a quote
Asking for a quote is easy: let us know the job and the location and its rough size. Photos by email help us understand the job, and we’ll take it from there.
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When to call us in Marylebone
Some movement joints have been pointed up with mortar by mistake. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Look out for any of the following:
- Joints with sealant missing in places
- Joints pointed up with cement by mistake
- Sealant pulling away from one side of the joint
- Damp patches traced to an open external joint
Rented homes near Bond Street station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Comparing quotes
- How much experience the applicator has
- Whether they’re fully insured
- Is VAT in the price?
- Whether all the old sealant comes out first
What we can’t put right
A few problems are outside what sealant work can do:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracking across the wall rather than at a joint
- Structural movement, which needs a surveyor or engineer
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly before you book.
What we seal
- Copings & trims
- Joints between brick and frames
- Brickwork movement joints
- Façade panels
- Render & cladding joints
- Concrete & block
Different surfaces, different methods
Render joints
Water behind render can lead to blown patches. A sound joint keeps the render dry behind and protects the render itself.
Copings and trims
Coping and trim joints face rain and sun head on. We reseal them with an exterior sealant suited to the material.