Greater London · England
Window Mastic in Gunnersbury
Window mastic in Gunnersbury from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Water coming in at the bottom corners of a door
- Hard, cracked sealant around windows
- Whistling draughts around closed windows
Why deal with it now?
Once mastic fails, rain can get between the frame and the wall. Left long enough, it can stain inside walls, spoil plaster and rot wooden frames. Resealing now is a small job by comparison. Converted houses in London often have a bathroom above someone else’s living room, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Putting it right early is much less trouble.
What it costs depends on the amount of work, how hard the old material is to remove and how easy the joints are to reach. You’ll have a clear quote before any work starts.
Why Gunnersbury customers choose us
- A sealant colour to suit the surroundings
- We never seal over old sealant
- Colour agreed with you before any work starts
- Neat joints and a tidy finish
See our cost guide or what customers say.
How we handle window mastic in Gunnersbury
The new joint does not have to be white. We can seal in white, brown, anthracite grey, black or clear, so the line suits the frame instead of standing out. We are often asked to deal with old mastic that has gone black or come away and gaps where the sill meets the wall, on uPVC windows, composite doors and patio & French doors.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first, and access in Gunnersbury is something to talk through when you book.
The work is guaranteed for twelve months. If something is not right with it in that time, tell us and we will put it right.
- Where
- Gunnersbury (W4, W3, TW8)
- Region
- Greater London
- Cover
- One year on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
How the job changes by surface
Aluminium frames
Bi-fold and sliding aluminium doors have long frame joints, and the bottom joint sees the most water. Each is cleaned, backed where deep and resealed.
Patio & French doors
Heavy door frames can move more than windows. The sealant must cope with it without cracking.
How to look after the new joints
So the new joints stay in good condition:
- Keep solvents and bleach off the sealant
- Walk round the house once a year and look at the joints
- Do not aim a pressure washer at the joints
- Don’t paint over the silicone
Timber frames need their paint kept up, since wood that gets wet swells and shrinks more. Keep paint off the silicone itself.
Signs to watch for: cracks in the mastic, gaps you can see light through, damp on the reveal or mould around the inside of the frame. Any of these is worth a call.
DIY versus a professional finish
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 fails, we can still redo it.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
What affects the cost of window mastic
Your quote is based on your job. We look at:
- How much old sealant there is and how hard it is to remove
- When we can work, for business premises
- How much there is to do
- Whether there’s mould to deal with
Doing several joints on one visit usually makes better use of the time than several visits. We will give you a clear price for the lot.
What we need to know
When you call or email, it’s useful to know:
- Roughly how big the job is
- Pictures of the joints, sent by email
- If someone has resealed it before
- Where the job is, and your postcode
Asking for a quote is easy: let us know the job and the location and its rough size. Photos by email help us understand the job, and we’ll come back to you with a quote.
Questions from Gunnersbury
Is parking an issue for window mastic in Gunnersbury?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Can you do window mastic in Gunnersbury?
Yes. We work across London and the South East, and Gunnersbury is part of that. You can ring 0345 464 0079 or send us an email and let us know what needs doing.
Will there be a smell?
It depends on the product. Some products have a noticeable smell, others very little.
I rent my home. Can I book you?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Can you reach windows above the ground floor?
Yes, in most cases. Access is planned before any work starts, so mention the height and anything in the way.
Can landlords and businesses book you?
Yes, regularly. We can quote for several properties at once, and between tenancies is a good time for the work.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
Can you do the inside joint as well?
Yes, we do both. Indoors, we seal between the frame and the plaster or reveal, using a paintable sealant if you want to decorate.
Towns and villages near Gunnersbury
What else we do in Gunnersbury
What window mastic looks like in Gunnersbury
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. Historic houses like Gunnersbury Park (about 0.7 miles north-west) are a reminder that the area around Gunnersbury has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
Gunnersbury is in London, so parking needs planning: let us know about parking bays, permits or a driveway. For an older house near a landmark such as St Michael's Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Letting a property close to Gunnersbury station? Then sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Gunnersbury is about 1 mile south of Acton, in Greater London. From the centre of Gunnersbury to the outskirts, window mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Gunnersbury is one of 764 towns and villages in Greater London we cover for window mastic. There’s also a page for London, roughly 8 miles from Gunnersbury.
Every address in W4, W3 and TW8 is within our area for window mastic, from the main roads to the quietest streets. You will find streets such as Kew Road, Kent Road and Power Road, and we cover them all. Gunnersbury is on the A3000, which makes it straightforward to reach with everything needed for window mastic. Nearby, we also carry out window mastic in Strand-on-the-Green (1 mile south), Kew (1 mile south), Grove Park (1 mile south-east), Chiswick (1 mile east) and Turnham Green (1 mile south-east). Further out, we also cover London (8 miles east), City of Westminster (6 miles east), Marylebone (6 miles east), Kensington (3 miles east), St Pancras (7 miles east) and Shoreditch (9 miles east).
Landmarks near Gunnersbury
Around Gunnersbury, our work takes us to homes and buildings near Clayton Hotel Chiswick, Kew College Prep and Ark Acton Academy, among other places. Also close by are Turnham Green (0.5 miles east) and Library for Iranian Studies (1 mile north). Gunnersbury has its own railway station: Gunnersbury station. Other landmarks nearby include Barnes Hospital (2 miles south-east) and Livat Hammersmith (2.1 miles east). For a walk, there’s Kew Gardens Lake and Castlebar Hill.
How the visit works
Most of a good job is in the preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it usually takes a few hours for a few frames, or a day or more for a whole house. In Gunnersbury, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We check each frame and agree which ones need doing.
- The old mastic is cut out and the surfaces cleaned back.
- Where gaps are deep, backing rod goes in first.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- Finally we tidy up and check each joint.
Getting ready for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about stairs, lifts or work at height
- For business premises, tell us about site rules or sign-in
Ask for a quote
To get a quote, ring 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. You’ll have a clear quote before any work starts.
Read more
Work for landlords, hotels and businesses
Landlords and agents in Gunnersbury can book us as well as householders. Resealing between tenancies keeps a property looking cared for before the next move-in.
Hotels need rooms back in use, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.