Greater London · England
Mapesbury Window Mastic
Window mastic in Mapesbury from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Cracked internal joints between frame and plaster
- Gaps left after new windows were fitted
- Cold air getting in at the frame edge
Can I do it myself?
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Window mastic in Mapesbury, done properly
Most frames have an outside joint and an inside one. Outside, the mastic keeps rain out; inside, the joint between frame and plaster stops draughts and tidies the reveal. Either or both can be done. Common call-outs are for white mastic on grey or black frames and water coming in at the bottom corners of a door, across window sills, composite doors and timber windows & doors.
Many London homes are flats, with windows high above the street. In a converted house or block, the lease normally says who is responsible for the windows, so it’s worth checking before booking, and access in Mapesbury is something to talk through when you book.
The work is covered for a year after we finish. If there’s a problem with it, please ring 0345 464 0079 or drop us an email.
- Location
- Mapesbury (HA9, HA0, NW10)
- Region
- Greater London
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Surface by surface
Composite doors
If the door itself is draughty, the issue may be the door seals or hinges rather than the frame mastic. We will tell you if that is what we find.
uPVC windows
Some uPVC windows were sealed at fitting with a quick bead that never bonded. We cut it out, back any deep gaps and reseal properly.
What happens on the day
Before we leave, we go over the finished joints with you and explain the cure time. The visit itself usually takes a few hours for a handful of frames, longer for a whole house, depending on the size of the job. In Mapesbury, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- First, we go round the frames with you and agree the list.
- The old mastic is cut out and scraped back to clean surfaces.
- Where the gap is deep, backing rod goes in first.
- The new sealant goes on in white, brown, anthracite grey, black or clear to suit.
- We tool each bead neatly and check every joint is closed.
Preparing for the visit
- Tell us about any water getting in
- Move anything stored near the joints
- For business premises, tell us about site rules or sign-in
Get a quote
Want a quote for window mastic? Please call 0345 464 0079 or drop us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
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For landlords and businesses
We also work for property managers and facilities teams in Mapesbury and across Greater London. Several sites can go on one quote, and we’re fully insured for the work.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
What window mastic looks like in Mapesbury
London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. With historic houses such as Pitzhanger Manor (about 3 miles south) nearby, there’s older building stock in the area around Mapesbury 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 is traditional sand mastic.
For landlords with property near Wembley Stadium station, renewing tired window mastic between tenants heads off draught and damp complaints. Homes close to St Michael the Archangel include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Managing a site like St Joseph's RC Infant School? Then its window and door frames need their mastic kept sound, just like a home’s.
Mapesbury is about 1 mile south-east of Wembley, in Greater London. From the centre of Mapesbury to the outskirts, window mastic is available for homes and businesses alike. Our Greater London coverage runs to 764 places, Mapesbury among them. Our London page covers work nearby (9 miles or so).
Jobs for window mastic in HA9, HA0 and NW10 is quoted and booked the same way as anywhere else. Local streets include London Road, Harrow Road and Cecil Avenue, all of which we cover. Other places close to Mapesbury include Tokyngton (1 mile south-east), Stonebridge Park (1 mile south-east), Wembley Park (1 mile north), Wembley (1 mile north-west) and Brent Park (1 mile east). Larger places within reach include London (9 miles south-east), City of Westminster (6 miles south-east), Marylebone (6 miles east), Kensington (5 miles south-east), St Pancras (7 miles east) and Shoreditch (9 miles east).
Around Mapesbury
In Mapesbury, that means homes and buildings near The Swaminarayan School, Hilton London Wembley pub and St. Raphael's Edible Garden and the streets around them. There’s a railway station in Mapesbury itself: Wembley Stadium station. Nearby you’ll also find Brent Museum and Archives (2.2 miles east) and Neasden Hospital (0.9 miles east). Not far away are Fox Wood and Middle Lake.
Leave it or put it right?
Running fresh sealant over the old joint is tempting, but new sealant can’t bond to old, crumbling mastic. It soon lifts and the leak carries on behind it. Proper resealing starts with removing the old joint. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Mapesbury, the repair is bigger than the sealant job would have been.
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
Why us?
- More than 20 years in sealant work
- One-year guarantee on every job
- Neat joints and a tidy finish
- Homes, businesses and hotels
Take a look at our cost guide or customer reviews.
Nearby places to Mapesbury
What else we do in Mapesbury
What sealant work cannot fix
Some problems need a builder, plumber or other trade rather than us:
- Misting between the panes of a double-glazed unit (that needs a new unit)
- A frame that has rotted at the joint
- Damp problems in the wall away from the window
If in doubt, call 0345 464 0079 or email us and we’ll say what we think.
Surfaces we seal
- Patio & French doors
- Timber windows & doors
- uPVC windows
- Aluminium frames
- Composite doors
- Window sills
How we quote for window mastic
We do not publish a price list. The quote depends on:
- How easy the joints are to reach
- The product the joint needs
- How many rooms, windows or areas are involved
- Whether there’s mould to deal with
Doing several joints on one visit generally makes better use of the time than several visits, so tell us about everything that needs sealing. We’ll send you a clear quote for the lot.
Helping us quote
To make quoting easier, please include:
- Whether it’s a home or a business
- Where the property is
- What’s wrong with the joints now
- If someone has resealed it before
There’s no standard price list. Instead, we give you a clear price for your job. To get started, ring 0345 464 0079 or drop us an email.
Mapesbury questions
Is parking a problem for a job in Mapesbury?
Parking in Mapesbury, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Can you help a landlord with a rental near Wembley Stadium station?
Yes, landlords and agents are among the people we work for. You can phone 0345 464 0079 or email us with the details for a clear quote.
Will there be a smell?
Possibly a little. Any smell clears as the sealant cures, and ventilation helps.
Which products do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
Will you leave a mess?
We keep the work tidy. We protect what’s around the joints, and the area is left clean when we finish.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint.
Does someone need to be in?
It depends on the job. Inside work needs someone to give us access.
What should I tell you?
The location, the problem and the rough size of the job. Photos by email help too.