Greater London · England
External & façade joints in Osterley, Greater London
Our applicators work in Osterley on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Rain getting behind render or cladding at a joint
- Panel joints letting water in
- Joints where the bead has come unstuck
Looking after it afterwards
So the new joints stay in good condition:
- Deal with leaking gutters that soak the joints below
- Avoid pressure-washing directly into sealant joints
- Have failed joints looked at early
- Keep movement joints as flexible joints, not mortar
Avoid pressure-washing straight into the joints. A strong jet can damage the edges of the bead and let water in behind.
Once a joint cannot move, the wall finds another way, generally as cracking in the brickwork or render nearby. Catch it early and you reduce the risk.
How we handle external mastic in Osterley
Low-level joints can usually be done from the ground. For joints higher up, give us some details of the building and we’ll confirm what access is needed. If you’re dealing with sealant that has lost its bond to the brick or render and movement joints filled with mortar instead of sealant, we can help, whatever the surface.
Modern London flats rely on sealed movement joints and cladding joints. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall, and both kinds of building are found across London.
You get a 12-month guarantee, the same in Osterley as everywhere else we work.
- Where
- Osterley (TW7, TW3, TW5)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
When it is not the sealant
A few problems are outside what sealant work can do:
- Rising or penetrating damp from elsewhere in the wall
- Cutting new joints into brickwork, which is building work rather than sealant work
- Loose or hollow render, which needs re-rendering
If you’re not sure, just ring 0345 464 0079 or email us and we will give you a straight answer before you book.
Where we work in Osterley
- Joints between brick and frames
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Façade panels
- Concrete & block
Walls and rooflines in Osterley
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. London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking.
For site and facilities teams at buildings such as Isleworth and Syon School for Boys, its movement joints, gutters and trims need looking after like any other building’s. Rented homes near Isleworth station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Osterley is about 1 mile north of Hounslow, in Greater London. For external mastic in and around Osterley, please call 0345 464 0079 or drop us an email for a quick quote. We cover Greater London from our Crawley base, Osterley included. Osterley is one of 764 towns and villages in Greater London where we work for external mastic. We also work in London, about 11 miles from Osterley.
Our applicators cover all of TW7, TW3 and TW5 for external mastic and the streets around it. Whether your property is on Jersey Road, Church Road and Gresham Road or a nearby road, we can help. We also cover the places around Osterley: Spring Grove (1 mile south-east), Lampton (1 mile south-west), Norwood Green (1 mile north-west), Gillette Corner (1 mile east) and Woodlands (1 mile south). Within a short drive, we also cover London (11 miles east), City of Westminster (9 miles east), Marylebone (9 miles east), Kensington (6 miles east), St Pancras (10 miles east) and Shoreditch (12 miles east).
Local landmarks in Osterley
Around Osterley, our work takes us to homes and buildings near The Plough Public House, Spring Grove Primary School and Inwood Park, among other places. Osterley’s nearest station is Isleworth station, about 0.9 miles south-east of the centre. A little further out are Museum of Army Music (2.1 miles south) and West Middlesex University Hospital (1.3 miles south-east). Not far away are Castlebar Hill and Garden Lake.
What we’re called out for in Osterley
UV, rain and frost all age exterior sealant. In time it goes hard, crazes on the surface and stops stretching, so the joint eventually tears or comes away from one side.
The most common problems we see are:
- Weathered mastic that no longer stretches
- Failed seals between different materials
- Water getting into walls through failed joints
- Joints with sealant missing in places
Osterley is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Questions to ask before booking
- Is the old sealant removed completely?
- What happens if they find a problem under the old sealant
- What product goes in the joint
- How much experience the applicator has
The process
All our tools and materials come with us in the van, so you don’t need to buy or prepare anything. After a quick look at the joints together, the area is protected and the work begins. Most jobs take a few hours to a few days, depending on the length of joint and the access. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- 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.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Let us know about earlier repairs to the joints
- Where the joints are inside, avoid wetting them before we arrive
- Tell us about any water getting in
Getting a quote
Getting a quote is simple: tell us what needs doing and where and its rough size. Photos by email help us understand the job, and we will come back to you with a quote.
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Osterley questions
Is parking an issue for external mastic in Osterley?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Do you work for landlords with property near Isleworth station?
Yes, we work for letting agents and landlords. Just phone 0345 464 0079 or send us an email and tell us about the property, and we’ll give you a clear quote.
Are you insured?
Yes. We’re fully insured, and we can confirm the details when we quote.
Can you seal joints between two different materials?
Yes. Materials like render, brick, metal and uPVC all move differently, so the joint between them must be flexible. We choose one that suits both surfaces.
When is the sealant fully cured?
Most sealants are touch-dry well before they’re fully cured. We will give you the cure time for the product we used.
How long does the job take?
As a guide, most jobs take anything from a few hours to several days, depending on the building. Larger jobs naturally take longer, and we will tell you how long to expect.
Is there any odour?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
Do you do commercial work?
Yes, regularly. Larger jobs can be planned room by room or area by area to suit the site.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it does not work out, we can still put it right.
Also near Osterley
Also in Osterley
What affects the cost of external mastic
We quote each job individually. These are the things that affect it:
- Whether old sealant or filler has to be cut out
- Mould in or behind the old joints
- Whether the work is at height
- How many areas need sealing
The cost reflects the work involved, not a rough estimate. That is why we ask a few questions first.
What we need to know
Photos by email are helpful but not essential. Please mention:
- Any access issues, like height or stairs
- The address or postcode of the job
- Whether it’s a home or a business
- Any previous sealing or DIY work
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and add pictures by email if you can.
Landlords, agents and businesses in Osterley
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
For anyone letting property in or around Osterley, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs.