Greater London · England
Window Mastic in North Kensington
Our applicators work in North Kensington on mastic around window and door frames, sills and patio doors. Old material cut out, joints cleaned and sealed neatly and a 12-month guarantee.
- A bead that does not match the frame
- Mastic that has split away from the wall
- Cracked internal joints between frame and plaster
Landlord and commercial work in North Kensington
Letting agents often deal with us directly. Tell us the address, the job and how access works and we’ll quote.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. Several properties can go on one quote.
Window mastic for homes and businesses in North Kensington
Colour matters on a frame. White, brown, anthracite grey, black and clear sealants are all available, so the bead blends with the window rather than framing it. If you have rain getting in at the frame or under the sill and cracked or shrunken mastic around the frame, we can help, on composite doors, window sills and aluminium frames alike.
Many London homes are flats, with windows high above the street. In a converted house or block, the lease usually says who is responsible for the windows, so it’s worth checking before booking.
The work is covered for a year after we finish. If anything isn’t right with it, phone 0345 464 0079 or drop us an email.
- Place
- North Kensington (W10, NW10, W11)
- Region
- Greater London
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
When something else is needed
A few problems are outside what sealant work can do:
- Worn gaskets, brush seals or a door that has dropped
- Penetrating damp from a failed cavity tray or render
- Misting between the panes of a double-glazed unit (that needs a new unit)
If in doubt, phone 0345 464 0079 or email us and we will say what we think before you book.
Joints and surfaces we work on
- Window sills
- Patio & French doors
- Composite doors
- uPVC windows
- Timber windows & doors
- Aluminium frames
What we do, step by step
Most of a good job is in the preparation, so that’s where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes a few hours for a handful of frames, longer for a whole house. For a job in North Kensington, parking and access are the things to plan: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- We start by checking each window and door with you.
- Next the failed sealant is cut away and the joint cleaned.
- Where gaps are deep, backing rod goes in first.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- We clear up and check every joint is fully closed.
Before we arrive
- Keep pets and children clear of the area while we work
- Clear items away from the joints we’re working on
- Mention any sign-in or site rules at work premises
Getting a quote
For a quote, phone 0345 464 0079 or email us with the location and a short description of the problem. We’ll send you a clear quote before any work starts.
Related advice
Signs you need window mastic in North Kensington
Joint shape matters as much as the product. A thin smear across a wide gap has nothing to it, and a gap filled solid can’t flex. Backing rod sets the right depth.
Any of these means the joints need attention:
- Black, perished sealant on frames
- Damp patches on the reveal after heavy rain
- Hard, cracked sealant around windows
- White mastic on grey or black frames
For an older house near a landmark such as Dissenters' Chapel, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Comparing quotes
- How long to leave it before use
- Whether VAT is included
- How the surfaces are prepared before sealing
- Which sealant they’ll use, and why
What happens if it’s left?
A cracked joint around a frame lets rain into the wall. Over time that can mean damp patches, damaged plaster and rotting timber. Resealing now is a small job by comparison. 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.
Combining jobs into one visit is normally more efficient than separate visits, so it’s worth mentioning everything you’d like done. We will send you a clear quote for the lot.
Why us?
- White, clear, grey or coloured to suit, where the product allows
- 4.9 on Google from 180+ five-star reviews
- More than 20 years in sealant work
- Quality sealants from Arbo and Everbuild
Take a look at how sealant jobs are priced and customer reviews.
Common questions in North Kensington
Can you help a landlord with a rental near Kensal Green station?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before we start.
Is parking an issue for window mastic in North Kensington?
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 reach windows above the ground floor?
Yes, where they can be reached safely. Tell us about access when you get in touch so we can plan the job.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done.
Where are you based?
Our base is in Crawley, and we work across South East England, London and Scotland.
Can I paint over the new sealant?
Not generally, if it’s silicone. We choose the product with your decorating in mind, so mention it when you book.
How many windows can you do in a day?
That depends on the number of frames, how they’re reached and the state of the old mastic. You’ll know the timing when we quote.
Do you have sealant for grey or black windows?
Yes, in most cases. Mention the frame colour when you ask for a quote and we will match it as closely as we can.
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. A few tips:
- Look round the frames every year or so
- Don’t use solvent cleaners on the joint
- Keep drainage slots and sill grooves clear
- Keep jet washers away from the mastic
Keep sill grooves and drainage slots clear, so rain drains out rather than building up at the sealant.
Look out for the warning signs: split or missing mastic, gaps, damp patches inside or black mould on the reveal. Any of these is worth a call.
How we quote for window mastic
The quote reflects the job in front of us. We look at:
- Which sealant suits the joint
- Access and height
- The old material and how stubborn it is
- Mould in or behind the old joints
What it costs depends on the size of the job, how much old material has to come out and how easy the joints are to reach. We give a clear quote before we start.
Asking for a quote
Photos by email are helpful but not essential. Please mention:
- Access, such as stairs, a lift or height
- Whether it has been sealed before
- Whether it’s a home or a business
- The address or postcode of the job
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.
Windows and doors in North Kensington
Historic houses like Kensington Palace (about 1.9 miles south-east) are a reminder that the area around North Kensington 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. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Rented homes near Kensal Green station change hands often, and renewing tired window mastic between tenants heads off draught and damp complaints. North Kensington is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
North Kensington is about 2 miles north-west of Kensington, in Greater London. North Kensington gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Our area takes in 764 places across Greater London, from the larger towns to small villages. For nearby work, see our London page (6 miles or so).
Jobs for window mastic in W10, NW10 and W11 works the same way as everywhere else we cover. Local streets include Peach Road, Barlby Road and Eynham Road, and we cover them all. Close by, we work in Kensal Town (1 mile east), Kensal Green (1 mile north-west), Kensal Rise (1 mile north), Notting Dale (1 mile south-east) and White City (1 mile south). We also work in nearby towns such as London (6 miles east), City of Westminster (3 miles east), Marylebone (3 miles east), St Pancras (4 miles east), Shoreditch (6 miles east) and Walthamstow (9 miles north-east).
Local landmarks in North Kensington
We work in homes and buildings around Little Wormwood Scrubs, Maida Vale School and The Eagle pub. The closest station to North Kensington is Kensal Green station, about 0.5 miles north of the centre. Other landmarks nearby include Princess Louise Hospital (under half a mile south-west) and Culture House (1.3 miles south). The countryside around North Kensington includes Campden Hill and Greville Place nature reserve.