Greater London · England
Window Mastic in Netherne on-the-Hill
Mastic around window and door frames, sills and patio doors for Netherne on-the-Hill, backed by a one-year guarantee. Call for a quick quote.
- Gaps where the sill meets the wall
- Cracked internal joints between frame and plaster
- Hard, cracked sealant around windows
Window mastic in Netherne on-the-Hill
A window frame and the wall around it expand and shrink at different rates. Heat and cold make frames grow and shrink against brick or render that hardly moves. So the sealant has to stretch and recover, which is why we use a low-modulus product. If you are dealing with gaps left after new windows were fitted and cracked sealant at the sill ends, we can help.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
We stand behind the work with a 12-month guarantee, so you’re not left on your own once the job is done.
- Where
- Netherne on-the-Hill (CR5)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
What sealant work can’t fix
A few problems are outside what sealant work can do:
- Penetrating damp from a failed cavity tray or render
- A failed sealed unit that has misted up
- Faulty window hardware
Not sure which it is? You can call 0345 464 0079 or send us an email and we will tell you honestly before you book.
Surfaces we seal
- Timber windows & doors
- Composite doors
- uPVC windows
- Patio & French doors
- Window sills
- Aluminium frames
More services for Netherne on-the-Hill
Quotes for window mastic in Netherne on-the-Hill
You’ll get a clear quote before any work starts. It takes into account:
- Whether old sealant or filler has to be cut out
- The type of sealant required
- Whether the work is at height
- Working hours on commercial sites
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
What we need to know
To make quoting easier, please include:
- The rough size of the job
- Whether it’s a home or a business
- What the problem is, such as mould, gaps, leaks or cracking
- A few photos by email, if you can
For a quick quote, get us on the phone, or email us if that is easier. Tell us about the joints that need doing and we will talk you through the work before giving you a price.
Why it’s worth doing now in Netherne on-the-Hill
Choosing the product is half the job. Decorators’ caulk and bathroom silicone aren’t designed for outside joints that move. An exterior, low-modulus sealant stays flexible in sun and frost. 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.
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote and we’ll talk you through it.
Why book with us
- Sanitary silicone with an anti-fungal additive in wet areas
- Neat joints and a tidy finish
- White, clear, grey or coloured to suit, where the product allows
- Colour agreed with you before any work starts
Common questions in Netherne on-the-Hill
Can you help a landlord with a rental near Coulsdon South station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can ring 0345 464 0079 or email us with the details for a clear quote.
Can you do window mastic in Netherne on-the-Hill?
Yes, Netherne on-the-Hill is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or drop us an email and tell us what needs doing, and we’ll give you a clear quote.
How long before the joint can be used?
Different products cure at different speeds, so please follow the time we give you when we finish.
Which products do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We’ll tell you what we’re using and why.
How long does it take to reseal the windows on a house?
That depends on the number of frames, how they’re reached and the state of the old mastic. We’ll tell you how long your job needs when we quote.
What should I tell you?
Let us know what needs doing and where, plus photos if you have them. We will ask anything else we need to know.
Can you seal the gap between the frame and the plaster indoors?
Yes. Plenty of draughts come through the inside joint as well as the outside, so it can be worth sealing both.
Does someone need to be in?
Access is agreed with you when the job is booked. Indoors, that usually means someone at home.
Keeping the joints in good condition
A little care helps the new joints last. We recommend:
- Look round the frames every year or so
- Keep timber frames painted
- Avoid harsh chemicals near the mastic
- Do not paint over the silicone
Keep the new mastic undisturbed while it cures, for as long as we advise. Keep jet washers away from the frames.
Wet, windy weather is when failed mastic shows itself, but resealing works best in dry conditions. Sorting cracked mastic early means the joint is sound before the bad weather.
For landlords and businesses
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
For anyone letting property in or around Netherne on-the-Hill, several properties can go on one quote. Send us the addresses and the work at each, and photos by email help.
Frames and glazing around Netherne on-the-Hill
In a converted house or block, who looks after the windows depends on the lease, so check that before booking. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Netherne on-the-Hill is in London, so parking needs planning: let us know about parking bays, permits or a driveway. For landlords with property near Coulsdon South station, renewing tired window mastic between tenants heads off draught and damp complaints. If you live in an older home near Church of St Margaret, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Netherne on-the-Hill is about 2 miles south of Coulsdon, in Greater London. Wherever you are in the CR5 postcode area, we can carry out window mastic at your property. We cover 764 towns and villages across Greater London, large and small. For nearby work, see our Crawley page (13 miles or so).
All of CR5 is covered for window mastic. Window mastic is available to properties on The Village Square, Rookery Mead and Netherne Lane. Nearby, we also carry out window mastic in Hooley (1 mile west), Merstham (2 miles south), Chaldon (2 miles south-east), South Merstham (2 miles south) and Gatton (2 miles south-west). Larger places within reach include London (14 miles north), City of Westminster (15 miles north), Kensington (15 miles north), Brompton (14 miles north), Stockwell (12 miles north) and Orpington (12 miles north-east).
Local landmarks in Netherne on-the-Hill
We work in homes and buildings around Shabden Park, among other places. The closest station to Netherne on-the-Hill is Coulsdon South station, roughly 1.6 miles north of the centre. Nearby you’ll also find The Belfry (3.8 miles south) and East Surrey Museum (2.9 miles east). For a walk, there’s South London Downs National Nature Reserve and Colley Hill.
What happens on the day
Every visit runs the same way: we look at the joints together, protect the area around them, do the work and clear up. Most jobs take anything from an hour or two to a full day, depending on how many frames there are. In Netherne on-the-Hill, 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.
- Deep gaps get closed-cell backing rod to set the depth.
- 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
- Move anything stored near the joints
- Mention any parking rules near the property
- Tell us about any water getting in
Get a quote
We don’t publish a price list. Instead, we give you a clear quote for your job. To get started, call 0345 464 0079 or email us.
Advice
How the job changes by surface
Patio & French doors
Water at the foot of a door frame isn’t always the mastic: blocked drain slots, worn brush seals and threshold details can let water in too. We look for the cause first.
Aluminium frames
Aluminium needs a sealant that bonds to coated metal, and acetoxy silicones are not used, as they can attack some metals. We use a neutral-cure product.