Greater London · England
Fortune Green Window Mastic
Window mastic in Fortune Green from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Damp patches on the reveal after heavy rain
- Hard, cracked sealant around windows
- Cracked sealant at the sill ends
Window mastic in Fortune Green
Frames and walls don’t move together. Heat and cold make frames grow and shrink against brick or render that hardly moves. That’s why the joint needs a flexible, low-modulus sealant rather than something rigid. We are often asked to deal with old mastic that has gone black or come away and damp patches on the reveal after heavy rain, on timber windows & doors, window sills and patio & French doors.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. Over the years, the sealant around them shrinks, cracks and pulls away, letting in draughts and water.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Place
- Fortune Green (NW3, NW6, NW2)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Signs you need window mastic in Fortune Green
On timber frames, paint and putty build up around the joint. Old mastic gets painted over and cracks under the paint, and the wood moves with damp as well as heat.
People normally contact us when they notice one of these:
- Draughty joints inside around the window
- Rushed sealant from a window installation
- Whistling draughts around closed windows
- Black, perished sealant on frames
If you live in an older home near Church of St Luke, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Questions to ask before you book
- How long to leave it before use
- Whether VAT is included
- How the colour is chosen
- Which sealant they’ll use, and why
When something else is needed
It helps to know what we can’t do too:
- Draughts through the window seals rather than the frame
- A frame that has rotted at the joint
- Damp coming through the wall itself rather than the frame joint
If you’re not sure, just ring 0345 464 0079 or send us an email and we will give you a straight answer before you book.
What we seal
- Window sills
- uPVC windows
- Aluminium frames
- Composite doors
- Timber windows & doors
- Patio & French doors
DIY sealant or a professional job?
A DIY attempt does not rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
Frames and glazing around Fortune Green
In a converted house or block, who looks after the windows depends on the lease, so check that before booking. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Letting a property close to West Hampstead Thameslink station? Then renewing tired window mastic between tenants heads off draught and damp complaints. As a London address, Fortune Green can be tricky for parking: let us know about parking bays, permits or a driveway.
Fortune Green is about 1 mile west of Hampstead, in Greater London. Fortune Green gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. 764 places in Greater London are on our list. You can also see our page for London, about 6 miles away.
Postcode districts we cover here for window mastic: NW3, NW6 and NW2. You will find streets such as Mill Lane, Ajax Road and Sarre Road. We also cover West Hampstead (1 mile east), Childs Hill (1 mile north), Hampstead (1 mile east), Greenhill (1 mile east) and Vale of Health (1 mile north-east). Further out, we also cover London (6 miles south-east), City of Westminster (3 miles south-east), Marylebone (3 miles south-east), Kensington (4 miles south), St Pancras (4 miles south-east) and Shoreditch (5 miles east).
Landmarks near Fortune Green
Typical jobs here are in homes near Holly Bush pub, St Vedasts School For Boys and Kilburn Grange Park. The closest station to Fortune Green is West Hampstead Thameslink station, roughly 0.5 miles south. Well-known places in the area include Montfichet's Tower (4.9 miles south-east) and O2 Centre (0.8 miles south-east). Green spaces nearby include The Long Water and Westbere Copse.
Why it’s worth doing now in Fortune Green
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished, and it’s easier while the walls are being worked on anyway. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
The cost depends on the size of the job, how much old material has to come out and access to the work. We give a clear quote before any work starts, so you know where you stand.
What you get with us
- Colour agreed with you before we start
- Trusted Arbo and Everbuild sealants
- Full insurance on every job
- 4.9 on Google from 180+ five-star reviews
Also near Fortune Green
More services for Fortune Green
How the visit works
Once we’re on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take a morning for a couple of windows and a door. For a job in Fortune Green, parking and access are the things to plan: let us know about parking, the floor we will be working on and any lift or shared entrance.
- We check how each frame can be reached safely.
- All the failed sealant is cut away.
- The surfaces are cleaned and left dry, and primed where the sealant calls for it.
- Backing rod fills deep voids and the sealant goes in on top.
- The joint is shaped to shed water and the area tidied.
How to prepare
- Keep pets and children clear of the area while we work
- Try not to wet indoor joints just before the visit
- Mention any parking rules near the property
Ask for a quote
For a quote, ring 0345 464 0079 or send us an email with the location and a short description of the problem. We will give you a clear price before any work starts.
Read more
Your questions about window mastic in Fortune Green
I let a flat near West Hampstead Thameslink station. Can you help?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or drop 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 Fortune Green?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Can I add another job to the visit?
Of course. Doing several areas at once is generally more efficient.
Can you work on commercial sites?
Yes. Larger jobs can be planned room by room or area by area.
Do you cover Fortune Green?
Yes. We’re based in Crawley and work across South East England, London and Scotland.
Can I do it myself?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
Where are you based?
We work from Crawley. Our applicators cover Fortune Green, along with the rest of our area.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Surface by surface
Aluminium frames
Aluminium moves with heat, and the frames are often slimmer than uPVC. A neat, narrow bead in a colour to match keeps the clean look.
Window sills
The end joints of a sill tend to fail before the rest. A tight seal at each end keeps rain out of the wall.
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Repaint timber before it’s bare
- Ventilate rooms so frames don’t stay wet inside
- Check the mastic once a year
- Clean frames with a soft cloth and soapy water
Keep sill grooves and drainage slots clear, so rain drains out rather than building up at the sealant.
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.