Greater London · England
External Mastic in Headstone
Sealing brickwork movement joints, render, cladding and façade joints for Headstone, backed by a 12-month guarantee. Call for a quick quote.
- Leaking joints around cladding and façade panels
- Sealant that has lost its bond to the brick or render
- Joints pointed up with cement by mistake
About our external mastic in Headstone
Where two different materials meet, such as brick and render or blockwork and metal, they move at different rates. A flexible exterior sealant takes up that movement where a rigid filler would soon crack. If you have rigid filler in a joint that should flex and failed sealant between panels on a façade, we can put it right, whatever the surface.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Headstone, tell us how high the joints are and how to reach the back of the building.
Each job carries a 12-month guarantee.
- Place
- Headstone (HA5, HA3, HA2)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What happens if it’s left?
A failed movement joint lets water into the wall and can run behind render or cladding. Dealing with it early keeps the repair to the joint, rather than the wall around it. 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 Headstone, the repair is bigger than the sealant job would have been.
We do not show prices on the 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’ll talk you through it.
Why us?
- We never seal over old sealant
- 20+ years of sealant experience
- We are fully insured
- White, clear, grey or coloured to suit, where the product allows
See what affects the cost and our reviews.
For landlords and businesses
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
We also work for property managers and facilities teams in Headstone and across Greater London. Several sites can be quoted together.
What we do, step by step
On the day, there’s very little for you to do. Point us to the joints and we’ll get on with it. The work itself takes a few hours for a handful of joints, longer for a whole elevation from start to finish. In Headstone, 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.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
Before we arrive
- For indoor joints, keep the area dry beforehand if you can
- On commercial sites, let us know about site rules
- Mention if the joints have been sealed before
Getting a quote
Need a quote? Please call 0345 464 0079 or send us an email and tell us about the job. We will explain what we’d do and give you a clear quote before we start.
Related advice
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Keep soil, plants and ivy away from the joints
- Wash walls gently around the sealant
- Walk round the building once a year and look at the joints
- Deal with leaking gutters that soak the joints below
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Once a joint cannot move, the wall finds another way, often as cracks near the joint. Catch it early and you reduce the risk.
Common questions in Headstone
Do you work for landlords with property near Headstone Lane station?
Yes, landlords and agents are among the people we work for. Just phone 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear quote.
Can you do external mastic in Headstone?
Yes, Headstone is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or drop us an email and let us know what needs doing, and we will give you a clear price.
What information do you need?
Just the basics: the address or postcode, what’s wrong and any access issues. After that, simply call 0345 464 0079 or email us.
Can I add another job to the visit?
Yes, and it often makes sense. Doing several areas at once is normally more efficient, so mention them when you ask for a quote.
What does external mastic cost?
It depends on the job, so we quote each one individually. To get one, call 0345 464 0079 or send us an email with a short description of the job.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Can you reach joints on upper floors?
That depends on the building and the joints. We work on joints that can be reached safely. Tell us about the building and we’ll confirm what access is needed.
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.
Outside joints around Headstone
With historic houses such as Headstone Manor (about 0.6 miles south-east) nearby, there’s older building stock in the area around Headstone as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking.
Headstone is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. Managing a site like Pinner Park Primary School? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. If you let a flat or house near Headstone Lane station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Headstone is about 1 mile east of Hatch End, in Greater London. Jobs in Headstone get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Headstone is one of 764 places in Greater London where we work for external mastic. We also work in London, about 14 miles from Headstone.
We work across the HA5, HA3 and HA2 postcode area for external mastic. External mastic is available to properties on Anselm Road, Ufford Road and Chantry Road. Other places close to Headstone include Hatch End (1 mile west), Harrow Weald (1 mile east), South Oxhey (2 miles north-west), Belmont (2 miles east) and Carpenders Park (2 miles north-west). We also work in nearby towns such as London (14 miles south-east), City of Westminster (11 miles south-east), Marylebone (11 miles south-east), Kensington (10 miles south-east), St Pancras (12 miles south-east) and Shoreditch (13 miles south-east).
Around Headstone
Typical jobs here are in homes near The Moon & Sixpence pub, Hatch End High School and Headstone Manor Recreation Ground, among other places. There’s a railway station in Headstone itself: Headstone Lane station. Nearby you’ll also find Hilfield Castle (3.8 miles north) and Kodak Museum (1 mile south-east). The countryside around Headstone includes Harrow Weald Common and Northala Fields.
When it isn’t the sealant
Some problems need a builder, plumber or other trade rather than us:
- Cracking across the wall rather than at a joint
- Movement that is more than a sealant joint can take
- Failed render or damaged cladding panels
If you are not sure, just ring 0345 464 0079 or email us and we will give you a straight answer.
Joints and surfaces we work on
- Brickwork movement joints
- Render & cladding joints
- Joints between brick and frames
- Copings & trims
- Façade panels
- Concrete & block
What the job involves on each surface
Joints between dissimilar materials
Each side of the joint may need its own preparation. We prepare both faces so the sealant bonds properly.
Concrete and blockwork
Wide joints in concrete need the depth controlling carefully. Backing rod sized to the joint sets it and keep the sealant to the right depth.
Also near Headstone
More services for Headstone
Can I do it myself?
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
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.