Greater London · England
External & façade joints in Brentford, Greater London
Specialist external mastic for Brentford: careful preparation, the right product and tidy work. Call for a quick quote.
- Hard, crazed mastic that has stopped moving
- Rain getting behind render or cladding at a joint
- Failed sealant between panels on a façade
External mastic in Brentford
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render so the joint doesn’t stand out. If you are dealing with failed seals between different materials and damp patches traced to an open external joint, we can help, on façade panels, concrete & block and brickwork movement joints alike.
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 Brentford, check the lease for who looks after the outside.
Whatever the size of the job, you get the same 12-month guarantee in Brentford and across Greater London.
- Location
- Brentford (TW8, W3, W4, W5)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
How it works
At the end, we look at the finished work together. The visit itself usually takes a few hours to a few days, depending on the length of joint and the access, depending on the size of the job. For a job in Brentford, parking and access are the things to plan: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- We start by walking round the building and agreeing the joints and the access.
- We cut out the old mastic and rake out anything in the joint.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Let us know about stairs, lifts or work at height
- On commercial sites, let us know about site rules
- Let us know about parking restrictions
Ask for a quote
We quote each job on its own, so the first step is telling us about yours. Just call 0345 464 0079 or send us an email with the details.
Related advice
Different surfaces, different methods
Concrete and blockwork
The face of concrete or block is often dusty, so preparation is key. We prime where the sealant needs it.
Render joints
Render is weaker at the surface than brick, so a low-modulus sealant is kinder to the joint edges. We prime where the product needs it.
Do you need external mastic in Brentford?
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. The joint can’t move, so the wall cracks somewhere else instead.
It’s worth asking for a quote if you see:
- Plants rooting in failed movement joints
- Hard, crazed mastic that has stopped moving
- Movement joints with cracked, split or missing sealant
- Sealant pulling away from one side of the joint
As a London address, Brentford can be tricky for parking: let us know about parking bays, permits or a driveway.
What your quote should include
- What the quote includes, VAT included or not
- What the cure time is
- Is the old sealant removed completely?
- How the colour is chosen
For landlords and businesses
For anyone letting property in or around Brentford, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs.
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
Towns and villages near Brentford
Other services in Brentford
How to look after the new joints
How long the joints last depends on use and care. We suggest:
- Look over the joints every year, ideally after winter
- Ask before painting over external sealant
- Keep water from gutters off the wall
- Have failed joints looked at early
If you have more work done on the wall, such as new render, cladding or an opening, show the contractor the movement joints. They should be kept open and resealed, not filled.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
What external mastic looks like in Brentford
In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts. Historic houses like Kew Palace (about 0.5 miles south-east) are a reminder that the area around Brentford has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
Schools such as St Paul's CofE Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. For an older house near a landmark such as Congregational Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Brentford is about 2 miles south of Ealing, in Greater London. If you need external mastic in Brentford, please call 0345 464 0079 or drop us an email for a quick quote. We cover Greater London from our Crawley base. Brentford is one of 764 towns and villages in Greater London where we work. Our London page covers work nearby.
We work across TW8, W3, W4 and W5 for external mastic and the streets around it. If you need external mastic at a property on High Street, Market Place and New Road or anywhere close by, we can help. Main roads around Brentford include the A4 and A315, so getting to you is simple. We also cover the places around Brentford: Brentford End (1 mile south-west), Northfields (1 mile north-west), Gillette Corner (1 mile west), Isleworth (2 miles south-west) and Spring Grove (2 miles west). Larger places within reach include London (9 miles east), City of Westminster (7 miles east), Marylebone (7 miles east), Kensington (4 miles east), St Pancras (8 miles east) and Shoreditch (10 miles east).
Near you in Brentford
Locally, jobs take us to homes and businesses close to Library for Iranian Studies, Brentford School for Girls and Kew College Prep, among other places. You’ll also find The Brook pub (less than half a mile south-west) and Kew Green (0.7 miles south-east). Brentford has its own railway station: Brentford station. A little further out are Treaty Centre (3 miles south-west) and Musical Museum (0.5 miles east). Open spaces near Brentford include Kew Gardens Lake and Long Wood.
How we quote for external mastic
The quote reflects the job in front of us. We take into account:
- Whether old sealant or filler has to be cut out
- Mould in or behind the old joints
- Access and height
- The type of sealant required
What it costs depends on the size of the job, how much old material has to come out and access to the work. We give a clear quote before any work starts, so you know where you stand.
What we need to know
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- What’s wrong with the joints now
- Whether it has been sealed before
- Access, such as stairs, a lift or height
- Whether it’s a home or a business
Need a quote? Please call 0345 464 0079 or email us and tell us about the job. We will explain what we’d do and give you a clear quote before any work starts.
Common questions in Brentford
Is Brentford in your area for external mastic?
Yes, Brentford is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job, and we will send you a clear quote.
Is parking a problem for a job in Brentford?
Parking in Brentford, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Is there any odour?
Some sealants have a smell while they cure. Ventilation helps.
Should I try DIY first?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Will it make a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
How long before the joint can be used?
Most sealants are touch-dry well before they’re fully cured. We’ll give you the cure time for the product we used.
Can I add another job to the visit?
Of course. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Are you fully insured?
Yes, we’re fully insured.
Should I try it myself first?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.