Greater London · England
External Mastic in Deptford
External mastic for Deptford and the surrounding area: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Gaps where render, brick and frames meet
- Sealant pulling away from one side of the joint
- Weeds or debris growing in open joints
How the visit works
When we arrive, we look over the joints with you first, so you know exactly what we’re doing. Surfaces next to the work are protected before we start. The work normally takes a few hours for a handful of joints, longer for a whole elevation. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Preparing for the visit
- Clear the area around the work
- Let us know about earlier repairs to the joints
- Try not to wet indoor joints just before the visit
Ask for a quote
It all starts with a short chat. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, ring 0345 464 0079 or email us.
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About our external mastic in Deptford
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we will confirm what access is needed. If you have movement joints with cracked, split or missing sealant and moss and dirt in joints with no sealant left, we can put it right.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Deptford, tell us how high the joints are and how to reach the back of the building.
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
- Deptford (SE8, SE10, SE14)
- Region
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Walls and rooflines in Deptford
Historic houses like Queen's House (about 1 mile east) are a reminder that the area around Deptford has older buildings as well as new. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts.
In the older streets around St. Paul's, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Managing a site like Tidemill Academy? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Deptford is about 3 miles south-east of Whitechapel, in Greater London. For external mastic in and around Deptford, it’s easy to get a quote: please ring 0345 464 0079 or drop us an email. We are based in Crawley and cover Greater London. Deptford is one of 764 towns and villages in Greater London we cover.
We work across SE8, SE10 and SE14 for external mastic and the streets around it. We cover properties on Mill Lane, Dixon Road and Clare Road. Deptford is on the A2209, which makes it straightforward to reach with everything needed for external mastic. If you’re just outside Deptford, we cover New Cross (1 mile south-west), St Johns (1 mile south), Millwall (1 mile north), Isle of Dogs (1 mile north-east) and North Greenwich (1 mile north-east). We also work in nearby towns such as London (3 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (8 miles west), St Pancras (5 miles north-west) and Shoreditch (4 miles north-west).
Around Deptford
Typical jobs here are in homes near Addey and Stanhope School, Sue Godfrey Nature Park and Deptford Arms, among other places. Deptford has its own railway station: Deptford station. Other landmarks nearby include Greenwich Castle (1.1 miles east) and Lewisham Shopping Centre (1.3 miles south-east). Open spaces near Deptford include Sue Godfrey Nature Park and Tower Hill.
FAQs for Deptford
Can you do external mastic in Deptford?
Yes, Deptford is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or send us an email and let us know what needs doing, and we’ll send you a clear quote.
Is parking an issue for external mastic in Deptford?
Parking in Deptford, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
What’s an expansion joint in brickwork?
A vertical gap in a long brick wall is generally a movement joint. It gives the wall room to move, and it should be sealed with a flexible sealant.
Are you an approved applicator?
Yes. Mr Mastic is an ARBOMaster approved applicator and we are fully insured too.
How long does external mastic take?
Typically it takes a few hours for a handful of joints, longer for a whole elevation. Bigger jobs take longer, and we’ll say how long yours will take.
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.
Can you seal joints between two different materials?
Yes. Joints between dissimilar materials are a big part of external work. The sealant is chosen to bond to both sides, primed where needed.
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.
When something else is needed
We will always be straight with you, so here’s what new sealant will not do:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Failed render or damaged cladding panels
- Cracking across the wall rather than at a joint
Not sure which it is? You can ring 0345 464 0079 or send us an email and we’ll tell you honestly.
Joints and surfaces we work on
- Render & cladding joints
- Façade panels
- Copings & trims
- Joints between brick and frames
- Brickwork movement joints
- Concrete & block
Work for landlords, hotels and businesses
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
We also work for property managers and facilities teams. Several sites can go on one quote, and we are fully insured.
Common problems we fix in Deptford
Poor preparation causes many early failures: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
Most people get in touch when they notice something like this:
- Moss and dirt in joints with no sealant left
- Rigid filler in a joint that should flex
- Sealant that has lost its bond to the brick or render
- Water getting into walls through failed joints
Deptford is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Before booking anyone
- Whether they seal over old material or remove it
- What happens if the job turns out different
- Who turns up on the day
- How the colour is chosen
Should I try it myself first?
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
How the job changes by surface
Cladding and façade panels
Panels heat up and cool down quickly, so the joint sealant has to cope with frequent movement. The sealant is chosen with that in mind.
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. We seal the joint with a flexible exterior sealant so the movement is taken up.
Why act early in Deptford
Resealing a run of joints in one go is usually better than patching one at a time. They’ve weathered the same way. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Deptford, the repair is bigger than the sealant job would have been.
Leaving a failed joint normally makes the job bigger, not smaller, because water and mould keep working on it. If you’re unsure, call 0345 464 0079 or drop us an email for an honest opinion and a quote.
Why book with us
- Sealant colour chosen to suit
- A 12-month guarantee on all work
- Old sealant always removed completely
- Approved under the ARBOMaster scheme
Read our cost guide and customer reviews.