Greater London · England
Window Mastic in New Eltham
Window mastic for New Eltham and the surrounding area: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Rushed sealant from a window installation
- Draughts coming in around windows and doors
- Cracked internal joints between frame and plaster
Window mastic in New Eltham, done properly
Frames and walls do not move together. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. So the sealant has to stretch and recover, which is why we use a low-modulus product. If you are dealing with whistling draughts around closed windows and old mastic that has gone black or come away, we can put it right, whatever the surface.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
You’re covered for a year from the day we finish. If there’s a problem with it, please phone 0345 464 0079 or drop us an email.
- Place
- New Eltham (SE9, DA15, BR7)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Landlords, agents and businesses in New Eltham
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Questions from New Eltham
Can parking be tricky for a visit in New Eltham?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly.
Is New Eltham in your area for window mastic?
Yes. Our work covers London and the South East, and New Eltham is part of that. You can phone 0345 464 0079 or drop us an email and tell us what needs doing, and we’ll give you a clear price.
I’m a tenant. Can you help?
Yes, but check with your landlord or agent first. Landlords are often happy for the work to be arranged.
How much does window mastic cost in New Eltham?
Every job is different, so each one gets its own quote. For a quick quote, phone 0345 464 0079 or drop us an email and let us know what needs doing and where.
Which products do you use?
The product depends on the job: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Can you match the sealant to my frames?
Yes, in most cases. Tell us the frame colour when you get in touch and we’ll use the nearest match.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Do you work for hotels and businesses?
Yes. Hotels, offices and other businesses use us.
What the job involves on each surface
Aluminium frames
Bi-fold and sliding aluminium doors have long frame joints, and the threshold joint takes a lot of water. We prepare and reseal every joint, backing the deep ones.
Composite doors
Front doors take the weather head on. We pay most attention there.
How the visit works
Good joint work is mostly preparation, and we don’t rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours for a handful of frames, longer for a whole house. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- We check each frame and agree which ones need doing.
- The old mastic is cut out and the surfaces cleaned back.
- Deep gaps are filled with backing rod to set the depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Every joint is checked before we leave.
Before we arrive
- Tell us about any previous sealing or DIY attempts
- Tell us about any water getting in
- Clear the area around the work
Getting a quote
Need a quote? Please ring 0345 464 0079 or send us an email with a few details. We’ll explain what we’d do and give you a clear price before any work starts.
Advice
Nearby places to New Eltham
Also in New Eltham
Should I try it myself first?
A DIY attempt does not rule out a professional job. We remove it and do the joint properly.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions.
Quotes for window mastic in New Eltham
There’s no set price list, because jobs vary so much. What we look at:
- How many rooms, windows or areas are involved
- When we can work, for business premises
- How much old sealant there is and how hard it is to remove
- The size of the job
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are not sure whether it needs doing, phone 0345 464 0079 or drop us an email and we will give you an honest view and a quote.
Helping us quote
You do not need to know the technical terms. It helps if you can tell us:
- Where the property is
- Any previous sealing or DIY work
- If it’s domestic, commercial or a hotel
- A few pictures by email, if you can
For a quote, call 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.
What window mastic looks like in New Eltham
In London conversions and blocks, the lease decides who is responsible for the frames, so check that before you book. 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.
If you live in an older home near All Saints Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame. Rented homes near New Eltham station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
New Eltham is about 1 mile south-east of Eltham, in Greater London. For window mastic in and around New Eltham, please call 0345 464 0079 or send us an email for a quick quote. We are based in Crawley and cover Greater London. New Eltham is one of 764 places in Greater London where we work. There’s also a page for London, about 8 miles away.
Work in SE9, DA15 and BR7 works the same way as everywhere else we cover. Window mastic is available to properties on Green Lane, Gerda Road and Novar Road. Nearby, we also carry out window mastic in Eltham (1 mile north-west), Longlands (1 mile south-east), Coldharbour (1 mile south-west), Avery Hill (1 mile north) and Blackfen (1 mile north-east). Further out, we also cover London (8 miles north-west), City of Westminster (11 miles north-west), Marylebone (11 miles north-west), Kensington (13 miles west), St Pancras (10 miles north-west) and Shoreditch (9 miles north-west).
Landmarks near New Eltham
In New Eltham, that means homes and buildings near Elmstead Wood and St Thomas More Catholic Comprehensive School. New Eltham has its own railway station: New Eltham station. Other landmarks nearby include Metropolitan Police Museum (1.4 miles east) and Eltham Community Hospital (1.1 miles north-west). Not far away are Summer Hill and The Tarn.
Signs you need window mastic in New Eltham
Sun, frost and rain wear sealant out. UV light hardens the outside of the bead, until it loses its stretch and starts to crack.
It’s worth asking for a quote if you see:
- Cracked or shrunken mastic around the frame
- Gaps where the sill meets the wall
- Gaps left after new windows were fitted
- Black, perished sealant on frames
If you look after a building such as Wyborne Primary School, its window and door frames need their mastic kept sound, just like a home’s.
What to look for in a quote
- Whether you can choose the colour
- How much experience the applicator has
- Whether the sealant suits the joint
- How hidden problems are handled
How to look after the new joints
How long the joints last depends on use and care. Here’s what we suggest:
- Ventilate rooms so frames don’t stay wet inside
- Keep jet washers away from the mastic
- Avoid harsh chemicals near the mastic
- Do not paint over the silicone
Timber frames need their paint kept up, because bare, wet timber moves more and pulls at the joint. Keep paint off the silicone itself.
Leaks normally show up in wet, windy weather, but resealing works best in dry conditions. Dealing with it when you first notice a crack avoids chasing leaks through the wet months.