Greater London · England
Chiswick Window Mastic
Mastic around window and door frames, sills and patio doors for householders, landlords and businesses in Chiswick. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Damp patches on the reveal after heavy rain
- Gaps where the sill meets the wall
- Mastic that has split away from the wall
Keeping the joints in good condition
How long the joints last depends on use and care. Here’s what we suggest:
- Don’t use solvent cleaners on the joint
- Clean frames with a soft cloth and soapy water
- Avoid blasting the frames with a pressure washer
- Air rooms to keep condensation down around windows
Most silicone sealants will not take paint, so if you are planning to paint the frames or walls, tell us beforehand. There are paintable sealants for joints that need it.
Water gets in quietly when mastic fails. Often the first sign is a damp patch inside or flaking paint on the reveal. Catching it early keeps the fix to a reseal.
Window mastic in Chiswick
Behind a thin line of old mastic there’s sometimes a deep void. Packing it solid with sealant gives a joint that can’t flex, so deep gaps get backing rod first. That way the new bead bonds to the frame and the wall only. Typical jobs include draughty joints inside around the window and gaps where the sill meets the wall, on patio & French doors, aluminium frames and window sills.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. Over the years, the sealant around them shrinks, cracks and pulls away, letting in draughts and water.
Big or small, it’s backed by our one-year guarantee in Chiswick and across Greater London.
- Location
- Chiswick (W4, SW14)
- Region
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear price before we start
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What happens if it’s left?
Running fresh sealant over the old joint is tempting, but new sealant cannot bond to old, crumbling mastic. It soon lifts and the leak carries on behind it. Proper resealing starts with removing the old joint. 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.
Leaving a failed joint generally makes the job bigger, not smaller, as water and mould keep getting in. If you’re unsure, ring 0345 464 0079 or email us for an honest opinion and a quote.
Why us?
- Colour agreed with you before any work starts
- 20+ years of sealant experience
- White, clear, grey or coloured to suit, where the product allows
- Any old sealant cut out fully, not covered over
Take a look at our cost guide or customer reviews.
How we quote for window mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- Working hours on commercial sites
- Whether old sealant or filler has to be cut out
- Whether there’s mould to deal with
- The number of rooms or windows
Combining jobs into one visit is normally more efficient than separate visits. We will give you a clear quote for the lot.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Whether it’s a home or a business
- A few photos by email, if you can
- Any access issues, like height or stairs
- If someone has resealed it before
Every job is quoted individually, so the first step is telling us about yours. Just ring 0345 464 0079 or email us with the details.
When it is not the sealant
Some problems need a builder, plumber or other trade rather than us:
- A failed sealed unit that has misted up
- Draughts through the window seals rather than the frame
- Soft or decayed wood in the frame
If you are not sure, just call 0345 464 0079 or email us and we will give you a straight answer.
Surfaces we seal
- Timber windows & doors
- Window sills
- uPVC windows
- Aluminium frames
- Composite doors
- Patio & French doors
Places near Chiswick
Also in Chiswick
How it works
There is not much for you to do on the day. Show us the job and we will take it from there. The work itself takes most of a day for a typical house, less for a few frames from start to finish. In Chiswick, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- First we look at every frame and agree the list.
- We remove the old mastic and clean the frame and the wall.
- We fit backing rod in deep gaps so the sealant is the right depth.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- Finally we tidy up and check each joint.
Before we arrive
- Let us know about earlier repairs to the joints
- Mention any tricky access
- Plan for the work area to be out of bounds to pets and children
Ask for a quote
It all starts with a short chat. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, phone 0345 464 0079 or email us.
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FAQs for Chiswick
Do you work for landlords with property near Chiswick station?
Yes. We work for letting agents and landlords as well as householders, and several properties can go on one quote. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
Can parking be tricky for a visit in Chiswick?
Parking in Chiswick, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Can new sealant go over the old?
No, it will not last. It can look neat for a few weeks, but the new layer lifts away from the old one. The old sealant has to come out completely.
Will there be a smell?
Sometimes, a little. Any smell clears as the sealant cures.
Will the old sealant be removed?
Yes, every time. New silicone doesn’t stick to old silicone, so the joint is cleaned back first.
What do you need from me for a quote?
Where the job is, what the problem is and roughly how big it is. If you can, email a few photos.
Does someone need to be in?
Access is agreed with you when the job is booked. Indoors, that usually means someone at home.
Is the new sealant paintable?
It depends on the sealant. Some hybrid sealants can be painted; silicone can’t. Mention any painting plans before work begins.
What window mastic looks like in Chiswick
With historic houses such as Hogarth's House (about 0.2 miles south-west) nearby, there’s older building stock in the area around Chiswick as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
Homes close to St. Nicholas Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Chiswick is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Chiswick is about 1 mile south of Acton, in Greater London. Across the W4 area, our applicators can take on window mastic. We cover 764 towns and villages across Greater London, from the larger towns to small villages. Our London page covers work nearby.
Every address in W4 and SW14 is covered for window mastic. You will find streets such as Pumping Station Road, Dale Street and Devonshire Road. Nearby, we also carry out window mastic in Turnham Green (1 mile south), Old Chiswick (1 mile south-east), Grove Park (1 mile south-west), Gunnersbury (1 mile west) and Strand-on-the-Green (1 mile west). We also work in nearby towns such as London (7 miles east), City of Westminster (5 miles east), Marylebone (5 miles east), St Pancras (6 miles north-east), Shoreditch (8 miles east) and Walthamstow (12 miles north-east).
Around Chiswick
Around Chiswick, our work takes us to homes and buildings near Polish Library POSK in London, Mawson Arms and Chiswick School. Also close by are Turnham Green (0.5 miles west) and The Swedish School (0.6 miles south-east). For rail, the closest station is Chiswick station, roughly 0.8 miles south-west. Nearby you will also find West London Hospital (1.5 miles east) and Kurdish Museum Library and Archive (0.8 miles east). For a walk, there’s Campden Hill and Duke's Hollow.
Surface by surface
Timber windows & doors
On period timber windows, traditional sand mastic is sometimes the better choice. We can talk through the options.
Aluminium frames
Aluminium moves with heat, and the frames are often slimmer than uPVC. A tidy bead in anthracite grey, black or a matching colour suits the frame.
What we are called out for in Chiswick
Water runs down the glass onto the sill, so the sill ends and the joint below the frame are common leak points. Failed sealant there lets rain into the wall or behind the frame.
The problems people generally mention when they call include:
- Gaps between the frame and the inside reveal
- Draughts coming in around windows and doors
- Cracked sealant at the sill ends
- Sealant in the wrong colour for the frame
For site and facilities teams at buildings such as The William Hogarth Primary School, the mastic around its windows and doors needs looking after like any other building’s.
What your quote should include
- How long the guarantee is
- Which colour the sealant will be
- How the surfaces are prepared before sealing
- Which sealant they’ll use, and why