Greater London · England
External & façade joints in Cowley, Greater London
External mastic across Cowley and nearby, with every bit of old sealant taken out first and a one-year guarantee.
- Brick movement joints where the sealant has split
- Rain getting behind render or cladding at a joint
- Failed seals between different materials
External mastic for homes and businesses in Cowley
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product. If you’re dealing with panel joints letting water in and joints pointed up with cement by mistake, we can put it right, on concrete & block, brickwork movement joints and façade panels alike.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall.
Every job comes with our 12-month guarantee.
- Location
- Cowley (UB8, UB7, UB10)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
What external mastic looks like in Cowley
With historic houses such as Ickenham Hall (about 2.9 miles north-east) nearby, there’s older building stock in the area around Cowley as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts.
Rented homes near West Drayton station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets. As a London address, Cowley can be tricky for parking: let us know about parking bays, permits or a driveway. Managing a site like Cowley St Laurence CofE Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
Cowley is about 2 miles south-west of Hillingdon, in Greater London. We carry out external mastic for homeowners, landlords and businesses in Cowley and the surrounding area, as part of our work across Greater London. Cowley is one of 764 towns and villages in Greater London where we work for external mastic. London is on our list too, around 17 miles away.
Our applicators cover all of the UB8, UB7 and UB10 postcode area for external mastic. Streets in the area include Iver Lane, High Road and The Avenue, all of which we cover. We also cover Uxbridge (1 mile north), Yiewsley (1 mile south-east), Hillingdon (2 miles north-east), Thorney (2 miles south) and New Denham (2 miles north). Further out, we also cover City of Westminster (14 miles east), Marylebone (14 miles east), Kensington (12 miles east), Hampstead (13 miles east), Ruislip (5 miles north-east) and Brompton (14 miles east).
Landmarks near Cowley
Around Cowley, our work takes us to homes and buildings near The Crown pub, Uxbridge High School and West Middlesex College and the streets around them. The closest station to Cowley is West Drayton station, roughly 1.3 miles south of the centre. Other landmarks nearby include British Airways Heritage Collection (0.7 miles north-west) and The Chimes (1.3 miles north). The countryside around Cowley includes Uxbridge Moor and Northala Fields.
Cowley: your questions answered
Do you cover Cowley for external mastic?
Yes, Cowley is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or email us and let us know what needs doing.
I let a flat near West Drayton station. Can you help?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can be quoted together. Just phone 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear price.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We will tell you what we are using and why.
Where are you based?
We work from Crawley. We cover Cowley and the rest of Greater London, along with the rest of our area.
Is there a guarantee?
Yes. Each job is guaranteed for twelve months, wherever you are.
Will the new joint stand out?
Exterior sealants are made in a range of colours, from greys and browns to whites and stone shades. We choose the closest to your brick or render so it does not stand out.
Why do you put foam in the joint first?
Backing rod goes into deeper joints as a matter of course. It controls the depth and stops the sealant bonding to the back so the bead can stretch.
Do I need to be at home?
Access is agreed with you when the job is booked. Indoors, that generally means someone at home.
Should I try it myself first?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions.
Why act early in Cowley
Running new sealant over the old bead rarely lasts. The new layer can’t bond properly to old, weathered material, so the old joint is cut out fully first. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, ring 0345 464 0079 or send us an email and we’ll give you an honest view and a quote.
Why Cowley clients choose us
- A 12-month guarantee on all work
- More than 20 years in sealant work
- Arbo and Everbuild products
- Anti-fungal silicone where joints get wet
Take a look at what affects the cost and our reviews.
What the job involves on each surface
Cladding and façade panels
Where a cladding system has its own specified sealant, we follow it, or one the system allows. Send us any details you have about the façade.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
How we quote for external mastic
Call for a quick quote. What matters most is:
- Any mould that needs treating
- The old material and how stubborn it is
- The number and length of the joints
- How easy the joints are to reach
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote and we’ll talk you through it.
What we need to know
To help us quote quickly, please include:
- Access, such as stairs, a lift or height
- What’s wrong with the joints now
- Where the job is, and your postcode
- Roughly how big the job is
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. Whenever you are ready, ring 0345 464 0079 or drop us an email.
Nearby places to Cowley
Also in Cowley
Landlords, agents and businesses in Cowley
Whether it’s one flat or a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
We work for landlords and agents as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
How the visit works
We bring everything the job needs with us, so there’s nothing for you to buy. Once we’ve agreed what’s being done, we protect the area and start. Most jobs take a few hours for a handful of joints, longer for a whole elevation. For a job in Cowley, 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.
- Every bit of old sealant and any mortar or debris is cut out.
- 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.
How to prepare
- Let us know about stairs, lifts or work at height
- Plan for the work area to be out of bounds to pets and children
- On commercial sites, let us know about site rules
Getting a quote
To get a quote, ring 0345 464 0079 or drop us an email with the location and a short description of the problem. We’ll send you a clear quote before any work starts.
Related advice
How to look after the new joints
Aftercare is simple, and it makes a real difference:
- Ask before painting over external sealant
- Walk round the building once a year and look at the joints
- Tell anyone working on the walls about the movement joints
- Make sure movement joints aren’t pointed over
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage, all bigger jobs than a reseal.