Greater London · England
Window & door mastic in Lee, Greater London
Window and door frames in Lee need attention? We cut out the old, prepare the joints and apply the right sealant.
- Mastic that’s falling out in pieces
- Cracked or shrunken mastic around the frame
- Cold air getting in at the frame edge
Surface by surface
uPVC windows
uPVC expands and contracts noticeably with temperature, so we use a flexible, low-modulus sealant. We match white, brown, anthracite grey and black frames.
Composite doors
An exposed front door gets wind-driven rain. We pay most attention there.
How we handle window mastic in Lee
There are two joints on most windows. Outside, the mastic keeps rain out; inside, the joint between frame and plaster stops draughts and tidies the reveal. We seal one or both, depending on what’s needed. If you are dealing with damp patches on the reveal after heavy rain and cracked internal joints between frame and plaster, we can put it right.
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, which is when draughts and damp patches appear in homes in Lee.
There’s a 12-month guarantee on every job, whatever its size.
- Where
- Lee (SE12, SE13, SE3)
- Region
- Greater London
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What affects the quote in Lee
Jobs vary more than people expect. The main factors:
- The number of rooms or windows
- The old material and how stubborn it is
- The product the joint needs
- The size of the job
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs. Call for a quick quote and we’ll go through it with you.
Asking for a quote
Photos by email are helpful but not essential. Please mention:
- What the problem is, such as mould, gaps, leaks or cracking
- If someone has resealed it before
- How we’d reach the joints
- How many joints, rooms or windows are involved
Getting a quote is simple: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job, and we’ll take it from there.
Window mastic in Lee: local notes
In a converted house or block, who looks after the windows depends on the lease, so check that before you book. With historic houses such as Eltham Palace (about 1.7 miles east) nearby, there’s older building stock in the area around Lee 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.
If you let a flat or house near Lee station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. For an older house near a landmark such as Church of the Good Shepherd, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. For site and facilities teams at buildings such as Brindishe Lee School, the mastic around its windows and doors needs looking after like any other building’s.
Lee is about 2 miles south of Greenwich, in Greater London. If you need window mastic in Lee, it’s easy to get a quote: please call 0345 464 0079 or email us. We are based in Crawley and cover Greater London. 764 places in Greater London are on our list, large and small. London is on our list too, around 6 miles away.
Jobs for window mastic in SE12, SE13 and SE3 works the same way as everywhere else we cover. If you need window mastic at a property on Old Road, Manor Lane and Mallet Road or anywhere close by, we can help. We also cover Hither Green (1 mile west), Horn Park (1 mile south-east), Lewisham (1 mile north-west), Ladywell (1 mile west) and Blackheath (1 mile north). Further out, we also cover London (6 miles north-west), City of Westminster (8 miles north-west), Marylebone (8 miles north-west), Kensington (10 miles west), St Pancras (7 miles north-west) and Shoreditch (6 miles north-west).
Landmarks near Lee
In Lee, that means homes and buildings near Manor House Gardens, Trinity Church of England School and International Academy of Greenwich. There’s a railway station in Lee itself: Lee station. A little further out are Lewisham Shopping Centre (1.1 miles north-west) and Prefab Museum (1.3 miles south). The countryside around Lee includes Summer Hill and Birdbrook Road Nature Reserve.
Other services in Lee
FAQs for Lee
I let a flat near Lee station. Can you help?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Can parking be tricky for a visit in Lee?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Do you cover Lee?
Yes. From our base in Crawley, we cover South East England, London and all of Scotland, Lee included.
Can I add another job to the visit?
Yes. Just list everything you need.
Can you seal the gap between the frame and the plaster indoors?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We do one or both.
Is it messy?
Tidy work is part of the job. We protect what’s around the joints, and the area is left clean when we finish.
Do you have sealant for grey or black windows?
Normally, yes. Mention the frame colour when you ask for a quote and we’ll match it as closely as we can.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
DIY versus a professional finish
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again.
What happens on the day
You don’t need to clear the whole room or building before we come, only the area right around the joints. Everything nearby is protected, and the job takes most of a day for a typical house, less for a few frames for a typical job. In a London area like Lee, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- 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
- Move anything stored near the joints
- Mention any parking rules near the property
- Tell us about any previous sealing or DIY attempts
How to get a quote
For a quote, phone 0345 464 0079 or email us with the location and a short description of the problem. You will have a clear quote before work begins.
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Looking after it afterwards
Looking after new joints is easy:
- Don’t paint over the silicone
- Clean frames with a soft cloth and soapy water
- Keep solvents and bleach off the sealant
- Check the mastic once a year
Keep the new mastic undisturbed while it cures, for as long as we advise. Don’t point a pressure washer at the joints.
Wet, windy weather is when failed mastic shows itself, but sealant goes on best when frames and walls are dry. Sorting cracked mastic early means the joint is sound before the bad weather.
Landlords, agents and businesses in Lee
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
What happens if it’s left?
Draughts and leaks don’t always mean new windows. Where the frames are sound, new mastic usually deals with draughts and leaks at the edges. If we find failed glass units or worn seals, we’ll tell you. 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 Lee, the repair is bigger than the sealant job would have been.
Doing several joints on one visit generally makes better use of the time than several visits. We’ll give you a clear price for the lot.
Why choose Mr Mastic in Lee
- We’re fully insured
- Old sealant always removed completely
- We leave the area clean and tidy
- 180+ five-star Google reviews
Take a look at our cost guide or our reviews.