Greater London · England
South Acton External Mastic
Movement joints in South Acton need attention? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Panel joints letting water in
- Weathered mastic that no longer stretches
- Gaps where render, brick and frames meet
How to look after the new joints
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Tell anyone working on the walls about the movement joints
- Wash walls gently around the sealant
- Make sure movement joints are not pointed over
- Get split or bare joints resealed while the damage is small
Keep the joints clear of soil, plants and climbing growth. Anything that holds water against the joint wears it out sooner.
Act while the splits are small. Then it’s a straightforward cut-out and reseal.
External mastic in South Acton
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. We work on render & cladding joints, joints between brick and frames and copings & trims, and common reasons people get in touch are water getting into walls through failed joints and cracked joints where brick meets render or frames.
Outside work in London starts with access: side passages, upper floors and where to park. In South Acton, joints up high may need ladders or other access, which is worth talking through when you book.
Each job carries a 12-month guarantee, large or small.
- Where
- South Acton (W3, W5, W4)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quotes
- A clear price before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
South Acton: your questions answered
I let a flat near South Acton station. Can you help?
Yes. We work for landlords and agents as well as homeowners. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear quote.
Can parking be tricky for a visit in South Acton?
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 does external mastic take?
It depends on the size of the job, but most jobs take a few hours for a handful of joints, longer for a whole elevation. We’ll tell you when we quote.
Why do you put foam in the joint first?
We fit closed-cell backing rod wherever the joint depth needs controlling. It sets the sealant depth and prevents three-sided bonding, so the joint can move.
Will it make a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
Can you do several jobs on one visit?
Yes. Several rooms, windows or areas can go on one quote.
Can you work on commercial sites?
Yes. We work in offices, washrooms, hotels and other commercial premises. Working times can be discussed when we quote.
Are you an approved applicator?
Yes. We hold ARBOMaster approved applicator status, and we are fully insured.
External mastic in South Acton: local notes
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Gunnersbury Park (about 0.3 miles south-west) nearby, there’s older building stock in the area around South Acton 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.
South Acton is in London, so parking needs planning: let us know about parking bays, permits or a driveway. For site and facilities teams at buildings such as Ark Acton Academy, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
South Acton is about 1 mile south-west of Acton, in Greater London. South Acton gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. South Acton is one of 764 towns and villages in Greater London where we work. For nearby work, see our London page (8 miles or so).
All of W3, W5 and W4 is covered for external mastic, from the main roads to the quietest streets. External mastic is available to properties on Power Road, Bollo Lane and Pope's Lane. If you are just outside South Acton, we cover Acton Green (1 mile east), Bedford Park (1 mile east), Acton (1 mile north-east), Hanger Hill (1 mile north) and Acton Vale (2 miles east). We also work in nearby towns such as London (8 miles east), City of Westminster (6 miles east), Marylebone (6 miles east), Kensington (4 miles east), St Pancras (7 miles east) and Shoreditch (9 miles east).
What’s near South Acton
Around South Acton, our work takes us to homes and buildings near Leap Service - the National Autistics Society, Berrymede Junior School and Library for Iranian Studies, among other places. Other local landmarks include Clayton Hotel Chiswick (0.6 miles south-east) and Gunnersbury Park (under half a mile south-west). For rail, the closest station is South Acton station, roughly 0.7 miles east of the centre. Other landmarks nearby include Livat Hammersmith (2.6 miles east) and Gunnersbury Park House - Large Mansion (less than half a mile south). For a walk, there’s Castlebar Hill and Kew Gardens Lake.
Honest limits
It helps to know what we can’t do:
- Adding movement joints to masonry that has none
- Cracks in the bricks or render themselves, away from the joints
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
If you are not sure, just phone 0345 464 0079 or email us and we’ll give you a straight answer before booking.
Surfaces we seal
- Joints between brick and frames
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Façade panels
- Render & cladding joints
Places near South Acton
Other services in South Acton
Common problems we fix in South Acton
Many joints fail because they were sealed too deep or with nothing behind them. Sealant bonded to three sides has nowhere to go and tears as soon as the joint widens.
If you can see any of these, it’s time to have the joints looked at:
- Joints where the bead has come unstuck
- Moss and dirt in joints with no sealant left
- Movement joints filled with mortar instead of sealant
- Failed sealant between panels on a façade
If you live in an older home near Church of All Saints, the joints between older walls, newer extensions and the roofline need a sealant that can move.
What your quote should include
- What product goes in the joint
- Is the old sealant removed completely?
- When the joint can take water or movement
- What happens if they find a problem under the old sealant
What happens on the day
We work through the job in order: protect, prepare, seal, tidy. Typically it takes a few hours for a handful of joints, longer for a whole elevation, and the area is left clean. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- First we look over the joints with you, agree which to renew and talk through access.
- The old mastic and anything lodged in the joint is removed.
- We clean both faces of the joint and prime them where the product calls for it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- Tell us about any previous sealing or DIY attempts
- Mention any leaks or damp you’ve noticed
- Mention any sign-in or site rules at work premises
Get a quote
For external mastic in South Acton, phone 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
Related advice
Should I try it myself first?
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
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.
Surface by surface
Joints between dissimilar materials
Different materials may need different primers. Both surfaces are cleaned and primed as the product requires.
Brickwork movement joints
Clay brickwork grows slightly over its life and moves with the weather. That movement goes into the joint, so its sealant has to stay flexible.
Leave it or put it right?
Pointing a movement joint with mortar might seem a neat fix, but it stops the joint moving. The wall then cracks somewhere else. The correct repair is a flexible sealant with the right backing. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in South Acton, the repair is bigger than a sealant job.
What it costs depends on the amount of work, how much old material has to come out and how easy the joints are to reach. You will have a clear quote before any work starts.
What you get with us
- Neat joints and a tidy finish
- Anti-fungal sanitary silicone in wet areas
- We are fully insured
- Colour picked to suit the job
Take a look at how sealant jobs are priced and customer reviews.