Greater London · England
Bexleyheath External Mastic
Movement joints in Bexleyheath need attention? We remove the old material, prepare the joints and seal them properly, with a one-year guarantee.
- Damp patches traced to an open external joint
- Joints with sealant missing in places
- Sealant that has lost its bond to the brick or render
How we handle external mastic in Bexleyheath
Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, and when it fails, the wall takes the strain and water finds a way in. Typical jobs include failed sealant between panels on a façade and sealant that has lost its bond to the brick or render, on façade panels, copings & trims 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 Bexleyheath, check the lease for who looks after the outside.
Your job is guaranteed for a year, as with all our work.
- Location
- Bexleyheath (DA7, DA6, DA16)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Signs you need external mastic in Bexleyheath
Buildings move more than people expect. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
If you can see any of these, it’s time to have the joints looked at:
- Joints pointed up with cement by mistake
- Cracked joints where brick meets render or frames
- Joints with sealant missing in places
- Hard, crazed mastic that has stopped moving
If you look after a building such as Upland Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Questions to ask before you book
- Are they insured?
- Which sealant they’ll use, and why
- How much experience the applicator has
- Is the old sealant removed completely?
Aftercare tips
To keep the joints looking good and working properly:
- Tell anyone working on the walls about the movement joints
- Keep soil, plants and ivy away from the joints
- Ask before painting over external sealant
- Have failed joints looked at early
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Small splits are the time to act. Then it’s a straightforward cut-out and reseal with no damage behind it to deal with.
What happens if it’s left?
Sealing over the top of old mastic does not hold for long. New sealant does not bond well to old, weathered sealant, so we always take the old sealant out. Damp from a failed joint spreads quietly in older London brickwork and timber, and once it shows in Bexleyheath, the repair is bigger than a sealant job.
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why book with us
- An ARBOMaster approved applicator
- Every job guaranteed for a year
- Tidy, careful work
- Anti-fungal silicone where joints get wet
Take a look at what affects the cost or customer reviews.
Walls and rooflines in Bexleyheath
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For an older house near a landmark such as Trinity Baptist Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Rented homes near Bexleyheath station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Bexleyheath is about 3 miles south-east of Plumstead, in Greater London. Jobs in Bexleyheath get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Bexleyheath is one of 764 towns and villages in Greater London where we work for external mastic. You can also see our page for London, about 10 miles away.
We cover every part of the DA7, DA6 and DA16 postcode area for external mastic and the streets around it. External mastic is available to properties on Lion Road, Hyde Road and Upton Road and the roads around them. Other places close to Bexleyheath include Upton (1 mile west), Crook Log (1 mile west), Blendon (1 mile south-west), Bexley (1 mile south) and Welling (1 mile west). We also work in nearby towns such as London (10 miles west), City of Westminster (13 miles west), Marylebone (13 miles west), Kensington (15 miles west), St Pancras (12 miles north-west) and Shoreditch (10 miles north-west).
Landmarks near Bexleyheath
Around Bexleyheath, our work takes us to homes and buildings near Danson Park, The Volunteer pub and Bexleyheath Academy and the streets around them. Bexleyheath has its own railway station: Bexleyheath station. Other landmarks nearby include Bexley Hospital (under half a mile west) and Bexley Museum (1.2 miles south-east). Open spaces near Bexleyheath include Summer Hill and Wansunt Pit.
How it works
We keep the work tidy and contained to the area we are working on. The job generally takes a few hours for a handful of joints, longer for a whole elevation. In Bexleyheath, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- 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.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Before we arrive
- Tell us about any water getting in
- Mention if the joints have been sealed before
- Move anything stored near the joints
Get a quote
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.
Read more
Surface by surface
Brickwork movement joints
Brick walls have vertical movement joints to absorb expansion. We reseal them with a low-modulus sealant over backing rod in a colour to suit the brick.
Copings and trims
Copings expand and contract through the day, so the joints need a sealant that stays flexible in all weathers.
Work for landlords, hotels and businesses
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we will quote.
Hotels need rooms back in use, so we plan the work room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
What affects the quote in Bexleyheath
We do not publish a price list. What we look at:
- How much there is to do
- Access and height
- Any working-time requirements on site
- The type of sealant required
Rather than a set price list, we price the job in front of us: the amount of work, the old material and the access. You’ll know the price before we begin.
What to tell us for a quote
To make quoting easier, please include:
- If it’s domestic, commercial or a hotel
- Pictures of the joints, sent by email
- Access, such as stairs, a lift or height
- The rough size of the job
For a quick quote, get us on the phone, or email us if that’s easier. Tell us about the joints that need doing and we will explain what’s involved.
More services for Bexleyheath
Common questions in Bexleyheath
Can you do external mastic in Bexleyheath?
Yes. We work across London and the South East, and Bexleyheath is part of that. You can phone 0345 464 0079 or send us an email and let us know what needs doing.
Is parking an issue for external mastic in Bexleyheath?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
What do you put in the joint?
Products from Arbo and Everbuild, among others, chosen to suit the joint. We explain the product when we quote.
Is the work guaranteed?
Yes: twelve months. If there’s a problem with our work in that time, tell us and we will put it right.
I’m a tenant. Can you help?
We are happy to deal with the tenant, landlord or agent. Just make sure your landlord agrees.
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.
Is it OK to seal over old sealant?
No, it won’t last. It may look fine at first, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Where do you work from?
We work from Crawley. Our applicators cover Bexleyheath.