Greater London · England
External Mastic in Southall
Professional external mastic in and around Southall, with old sealant always removed completely.
- Panel joints letting water in
- Rain getting behind render or cladding at a joint
- Old sealant gone brittle and cracked
External mastic for homes and businesses in Southall
Movement joints let brickwork, render and cladding expand and shrink without cracking. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. If you are dealing with cracked joints where brick meets render or frames and damp patches traced to an open external joint, we can help, whatever the surface.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. In Southall, joints up high may need ladders or other access, which is worth talking through when you book.
You’re covered for a year from the day we finish. If anything is not right with it, call 0345 464 0079 or drop us an email.
- Place
- Southall (UB2, UB1, UB6, W7)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Outside joints around Southall
Historic houses like Osterley House (about 1.7 miles south-east) are a reminder that the area around Southall 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. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For an older house near a landmark such as Saint John, older walls, gutters and the joints where extensions meet them need a flexible sealant. For landlords with property near Southall station, split movement joints are easy to miss on a rental until damp shows inside.
Southall is about 3 miles west of Ealing, in Greater London. If you need external mastic in Southall, please call 0345 464 0079 or email us for a quick quote. We cover Greater London from our Crawley base. Our Greater London coverage runs to 764 places, Southall among them. You can also see our page for London, about 12 miles away.
Postcode districts we cover here for external mastic: UB2, UB1, UB6 and W7. That includes homes and businesses on Uxbridge Road High Street, Emerald Square and Randolph Road and the roads around them. If you are just outside Southall, we cover Dormers Wells (1 mile north-east), West Ealing (2 miles east), Yeading (2 miles north), Yiewsley (2 miles north) and Hanwell (2 miles east). Larger places within reach include London (12 miles east), City of Westminster (10 miles east), Marylebone (10 miles east), Kensington (8 miles east), St Pancras (11 miles east) and Shoreditch (13 miles east).
Around Southall
Around Southall, our work takes us to homes and buildings near Minet Country Park, Glassy Junction pub and Villiers High School. Southall has its own railway station: Southall station. Well-known places in the area include Treaty Centre (2.8 miles south) and Museum of Army Music (3.8 miles south). Green spaces nearby include Northala Fields and Middle Lake.
What affects the cost of external mastic
For a quick quote, just ask. The main things that affect it are:
- How much old sealant there is and how hard it is to remove
- The size of the job
- Whether there’s mould to deal with
- Whether the work is at height
A failed joint rarely gets cheaper to fix by waiting. If you are not sure whether it needs doing, phone 0345 464 0079 or email us and we will give you an honest view and a quote.
Asking for a quote
When you contact us, it’s useful to know:
- The problem you’ve noticed
- How many joints, rooms or windows are involved
- Access, such as stairs, a lift or height
- If it’s domestic, commercial or a hotel
For external mastic in Southall, ring 0345 464 0079 or email us. Tell us what the problem is and where, and you’ll get a clear quote before work begins.
What the job involves on each surface
Copings and trims
Copings expand and contract through the day, so a flexible sealant suits them best year round.
Render joints
Rendered walls have joints at beads, openings and changes of material. We reseal them with a flexible exterior sealant that suits the render colour.
Landlords, agents and businesses in Southall
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can be quoted together.
FAQs for Southall
Is Southall in your area for external mastic?
Yes, Southall is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job.
I let a flat near Southall station. Can you help?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can ring 0345 464 0079 or email us with the details for a clear quote.
Can you quote for more than one area?
Yes, and it often makes sense. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Do I have to be there?
It depends on the job. For work indoors, someone needs to let us in, and for outside work we’ll agree access with you when we book.
Can a movement joint be filled with mortar?
No. A mortar-filled joint can’t move, so the wall cracks somewhere else instead. It needs a flexible sealant over backing rod.
What sealant do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Why do you put foam in the joint first?
That is backing rod, a closed-cell foam. It keeps the sealant at the right depth and bonded to the sides only.
Can I do it myself?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
When to call us in Southall
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.
People generally contact us after spotting one of these:
- Water getting into walls through failed joints
- Joints pointed up with cement by mistake
- Sealant that has lost its bond to the brick or render
- Old sealant gone brittle and cracked
As a London address, Southall can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Before booking anyone
- Which sealant they’ll use, and why
- What preparation is included
- Whether you can choose the colour
- Is the old sealant removed completely?
When something else is needed
Before booking, it’s worth knowing the limits too:
- Subsidence or other structural problems
- Rising or penetrating damp from elsewhere in the wall
- Walls that need new movement joints cut into them
If you are not sure, just phone 0345 464 0079 or send us an email and we’ll give you a straight answer.
Where we work in Southall
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Joints between brick and frames
- Concrete & block
- Façade panels
Looking after it afterwards
After the cure time, these simple habits help:
- Keep movement joints as flexible joints, not mortar
- Fix overflowing gutters above sealed joints
- Act on the first splits you see
- Tell anyone working on the walls about the movement joints
Follow the cure time we give you before the joint is knocked or disturbed. Most exterior sealants skin fast but take longer to cure right through.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years so early resealing is worth it.
Places near Southall
Other services in Southall
The process
Good joint work is mostly preparation, and we do not rush it. Joints are cleaned back and dried before anything new goes in. All told, the work takes a few hours for a handful of joints, longer for a whole elevation. For a job in Southall, parking and access are the things to plan: let us know about parking, the floor we will be working on and any lift or shared entrance.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- 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
- Keep children and pets away from the work area
- Let us know about stairs, lifts or work at height
How to get a quote
Every job is quoted individually. Simply phone 0345 464 0079 or send us an email and describe the job.