Greater London · England
Window & door mastic in New Addington, Greater London
Mastic around window and door frames, sills and patio doors in New Addington, with a one-year guarantee on every job. Ask us for a quote.
- Cracked or shrunken mastic around the frame
- Mastic that is falling out in pieces
- Damp patches on the reveal after heavy rain
Window mastic in New Addington
There are two joints on most windows. The external joint is the weather seal; inside, the joint between frame and plaster stops draughts and tidies the reveal. We seal one or both, depending on what’s needed. We work on uPVC windows, composite doors and aluminium frames, and people most often call us about gaps between the frame and the inside reveal and leaking joints at the ends of sills.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. The mastic around them dries out and cracks with age, letting in draughts and water.
We stand behind the work with a one-year guarantee, so you’re not left on your own once the job is done.
- Place
- New Addington (CR0, CR9)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What happens on the day
There is not much for you to do on the day. Point us to the joints and we’ll get on with it. The job generally takes anything from an hour or two to a full day, depending on how many frames there are from start to finish. In New Addington, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- 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.
- Every joint is tooled smooth and checked before we leave.
Preparing for the visit
- Keep pets and children clear of the area while we work
- Tell us about any previous sealing or DIY attempts
- For indoor joints, keep the area dry beforehand if you can
Get a quote
To get a quote, phone 0345 464 0079 or send 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
Honest limits
Honest advice matters more to us than a booking, so here’s what sealant cannot fix:
- Condensation trapped between the panes
- Soft or decayed wood in the frame
- Penetrating damp from a failed cavity tray or render
If in doubt, ring 0345 464 0079 or send us an email and we will say what we think before booking.
What we seal
- Timber windows & doors
- uPVC windows
- Composite doors
- Aluminium frames
- Window sills
- Patio & French doors
What happens if it’s left?
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished. 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.
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote.
What you get with us
- White, clear, grey or coloured to suit, where the product allows
- Old sealant always removed completely
- 180+ five-star Google reviews
- Quality sealants from Arbo and Everbuild
See our cost guide and customer reviews.
Can I do it myself?
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
Common problems we fix in New Addington
A lot of older mastic was never designed to stay flexible. Once it has hardened, the frame’s movement tears it from the wall, and a gap opens along one edge.
Signs it’s time to call us include:
- Cold air getting in at the frame edge
- Gaps between the frame and the inside reveal
- Sealant in the wrong colour for the frame
- Untidy mastic left by window fitters
If you live in an older home near St Edward King and Confessor, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Comparing quotes
- How hidden problems are handled
- How long the guarantee is
- Whether the sealant suits the joint
- What preparation is included
Landlords, agents and businesses in New Addington
We also work for property managers and facilities teams. Several sites can be quoted together, and we are fully insured for the work.
In hotels, rooms out of use cost money, so we plan the work room by room. Hotel work is part of what we do, alongside homes and businesses.
Questions from New Addington
Can you do window mastic in New Addington?
Yes, New Addington is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear quote.
Is parking a problem for a job in New Addington?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Are you fully insured?
Yes. Mr Mastic is fully insured.
I rent my home. Can I book you?
We are happy to deal with the tenant, landlord or agent. Just make sure your landlord agrees.
Will resealing my frames help with draughts?
Yes, where the draught is at the frame edge. We check where the draught is before we start.
Where is Mr Mastic based?
We’re based in Crawley, and we work across South East England, London and Scotland.
Do I have to be there?
It depends on the job. For work indoors, someone needs to let us in, and for outside work we will agree access with you when we book.
Do you work for landlords and businesses?
Yes. We work in homes, commercial premises and hotels, and we are fully insured.
Also near New Addington
Also in New Addington
How to look after the new joints
No joint lasts for ever, but care makes a real difference. A few tips:
- Clear any debris from frame drain holes
- Repaint timber before it’s bare
- Keep jet washers away from the mastic
- Use gentle cleaners on frames and sealant
Check the drainage slots in the frames are not blocked, so rain drains out rather than building up at the sealant.
A small gap around a frame only grows. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. A new joint closes it up.
Windows and doors in New Addington
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. Historic houses like Addington Palace (about 1.5 miles north-west) are a reminder that the area around New Addington has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
Letting a property close to Hayes (Kent) station? Then renewing tired window mastic between tenants heads off draught and damp complaints. Managing a site like Rowdown Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
New Addington is about 4 miles south-east of Croydon, in Greater London. For window mastic in and around New Addington, it’s easy to get a quote: please phone 0345 464 0079 or drop us an email. We cover Greater London from our Crawley base, New Addington included. Our Greater London coverage runs to 764 places, and New Addington is one of them. We also work in London, about 11 miles from New Addington.
Every address in CR0 and CR9 is covered for window mastic, from the main roads to the quietest streets. Whether your property is on Bothwell Road, Windham Avenue and Gascoigne Road or a nearby road, our applicators can take on the job. We also cover the places around New Addington: Forestdale (1 mile west), Fickleshole (1 mile south), Addington (1 mile north-west), Farleigh (1 mile south-west) and Selsdon (2 miles west). Further out, we also cover London (11 miles north), City of Westminster (13 miles north-west), Marylebone (13 miles north-west), Kensington (14 miles north-west), St Pancras (13 miles north) and Shoreditch (13 miles north).
Near you in New Addington
Around New Addington, our work takes us to homes and buildings near Meridian High School and Addington Vale and the streets around them. New Addington’s nearest station is Hayes (Kent) station, roughly 2.6 miles north-east of the centre. A little further out are Warlingham Park Hospital (1.8 miles south) and Bethlem Museum of the Mind (3.3 miles north-east). The countryside around New Addington includes Nore Hill and Hutchinson's Bank.