Greater London · England
External & façade joints in Greenwich, Greater London
External mastic for Greenwich, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Plants rooting in failed movement joints
- Movement joints filled with mortar instead of sealant
- Joints where the bead has come unstuck
Looking after it afterwards
Good habits help new joints last longer. A few tips:
- Fix overflowing gutters above sealed joints
- Wash walls gently around the sealant
- Look over the joints every year, ideally after winter
- Tell anyone working on the walls about the movement joints
Keep pressure washers away from the sealant. High-pressure water can lift the edges over time.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.
External mastic for homes and businesses in Greenwich
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Some surfaces need a primer before sealing. We’re often asked to deal with movement joints filled with mortar instead of sealant and rain getting behind render or cladding at a joint, across joints between brick and frames, façade panels and copings & trims.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
All our work comes with a 12-month guarantee, wherever you are in Greater London.
- Where
- Greenwich (SE10, SE3, SE8)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Also near Greenwich
What else we do in Greenwich
Landlord and commercial work in Greenwich
Failed sealant is one of the commonest items on a check-out report. We can quote for more than one property at once.
Landlords and letting agents in Greenwich can book us as well as householders. Sealant work between tenants keeps a property looking cared for before the next move-in.
What happens if it’s left?
The longer a joint stays open, the more water the wall takes in. In cold weather, frost can damage wet brick and render, so the damage spreads beyond the joint. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Putting it right early is much less trouble.
What you pay reflects the work, not a rough estimate. That is why we ask about the job first and agree the price before starting.
What you get with us
- Arbo and Everbuild products
- We agree the colour with you first
- White, clear, grey or another colour, product permitting
- Every job guaranteed for a year
Take a look at what affects the cost and customer reviews.
Can I do it myself?
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
External mastic in Greenwich: local notes
With historic houses such as Queen's House (about 0.2 miles north-west) nearby, there’s older building stock in the area around Greenwich as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Schools such as Meridian Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Rented homes near Maze Hill station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets. Greenwich is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Greenwich is about 4 miles east of London, in Greater London. Across the SE10 area, we cover external mastic for homes and businesses. Our area takes in 764 places across Greater London, from the larger towns to small villages.
We work across SE10, SE3 and SE8 for external mastic and the streets around it. Whether your property is on Cade Road, Webb Road and Creek Road or anywhere close by, we can help. You’ll find Greenwich on the A2203 and A2211, which makes it straightforward to reach. Other places close to Greenwich include Maze Hill (1 mile north-east), Vanbrugh Park Estate (1 mile east), Blackheath (1 mile south-east), Westcombe Park (1 mile east) and Isle of Dogs (1 mile north-west). We also work in nearby towns such as London (4 miles west), City of Westminster (7 miles west), Marylebone (7 miles west), Kensington (9 miles west), St Pancras (6 miles north-west) and Shoreditch (5 miles north-west).
Around Greenwich
We work in homes and buildings around The Plume of Feathers pub, John Roan School and Royal School of Naval Architecture and Marine Engineering. Also close by are Island Gardens (0.6 miles north-west) and St. Paul's (1.1 miles west). Greenwich has its own railway station: Maze Hill station. Well-known places in the area include Greenwich Castle (less than half a mile south-west) and Greenwich District Hospital (0.5 miles north-east). The countryside around Greenwich includes Tower Hill and Creekside Discovery Centre.
How the job changes by surface
Copings and trims
Coping joints that leak let water straight down into the wall. Resealing them is a small job that protects a lot.
Render joints
Cracks along render joints let water in behind the coat. A sound joint keeps the render dry behind.
FAQs for Greenwich
Do you cover Greenwich for external mastic?
Yes, Greenwich is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and tell us what needs doing, and we will give you a clear quote.
Is parking a problem for a job in Greenwich?
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 long before the joint can be used?
It depends on the product. Before we leave, we’ll tell you the cure time.
Where do you work from?
Our base is in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
What is a movement joint?
It’s a deliberate gap that lets the wall expand and contract without cracking. It’s sealed with a flexible sealant, not mortar.
What does external mastic cost?
Every job is different, so each one gets its own quote. To get one, call 0345 464 0079 or send us an email and tell us what needs doing and where.
Do you use backing rod?
The foam is closed-cell backing rod. It keeps the sealant at the right depth and bonded to the sides only, which would stop it stretching.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done and we will quote it together.
The process
The work is kept neat and contained to the area we’re working on, so you can get on with your day. Expect the work to take anything from a few hours to several days, depending on the building, and we explain the cure time before we leave. In Greenwich, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Getting ready for the visit
- Tell us if parking is tricky
- Move anything stored near the joints
- Keep pets and children clear of the area while we work
Ask for a quote
Want a quote for external mastic? Please phone 0345 464 0079 or drop us an email with a few details. We’ll explain what we’d do and give you a clear quote before any work starts.
Related advice
Honest limits
A few problems are outside what sealant work can do:
- Failed render or damaged cladding panels
- Rising or penetrating damp from elsewhere in the wall
- Adding movement joints to masonry that has none
Not sure which it is? You can call 0345 464 0079 or send us an email and we will tell you honestly before booking.
What we seal
- Joints between brick and frames
- Concrete & block
- Render & cladding joints
- Copings & trims
- Façade panels
- Brickwork movement joints