West Sussex · England
Copthorne Window Mastic
Mastic around window and door frames, sills and patio doors for householders, landlords and businesses in Copthorne. Fully insured, ARBOMaster approved and guaranteed for a year.
- Black, perished sealant on frames
- White mastic on grey or black frames
- Mastic that has split away from the wall
Window mastic in Copthorne, done properly
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 have black, perished sealant on frames and draughts coming in around windows and doors, we can put it right, whatever the surface.
Homes around Copthorne range from older properties to newer houses, and their windows range just as widely. The right sealant depends on the frame and on what it sits in.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Location
- Copthorne (RH10, RH6)
- Region
- West Sussex
- Cover
- A year, on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Leave it or put it right?
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. Homes in smaller places like Copthorne can face more weather, and failed outside joints let damp into walls. Inside, a split seal lets water into floors and panels just as it would anywhere.
The cost reflects the work involved, not guesswork. That’s why we ask a few questions first.
What you get with us
- White, clear, grey or coloured to suit, where the product allows
- Anti-fungal sanitary silicone in wet areas
- Any old sealant cut out fully, not covered over
- Every job guaranteed for a year
Nearby places to Copthorne
Other services in Copthorne
Surface by surface
Timber windows & doors
Timber moves with moisture as well as heat, so the joint must stay flexible. The paint or stain needs to be sound where the sealant meets it.
Composite doors
If the door itself is draughty, the issue may be the door seals or hinges rather than the frame mastic. We seal the frame and let you know about anything else.
The process
Once we’re on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. After that, the work takes a morning for a couple of windows and a door. A visit to Copthorne is planned like any other: the time, the access and where to park are agreed in advance. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We check how each frame can be reached safely.
- All the failed sealant is cut away.
- Frame and wall are cleaned and must be dry before sealing.
- Deep voids are backed, then the sealant is gunned in.
- We tool the joint so water runs off, then clear up.
Before we arrive
- For business premises, tell us about site rules or sign-in
- For indoor joints, keep the area dry beforehand if you can
- Let us know about parking restrictions
Ask for a quote
Need a quote? Please call 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and give you a clear quote before we start.
Advice
Do you need window mastic in Copthorne?
Sun, frost and rain wear sealant out. UV light hardens the outside of the bead, until it loses its stretch and starts to crack.
Any of these means the joints need attention:
- Rushed sealant from a window installation
- White mastic on grey or black frames
- Draughts coming in around windows and doors
- Rain getting in at the frame or under the sill
For site and facilities teams at buildings such as Fairway Infant School, its window and door frames need their mastic kept sound, just like a home’s.
Comparing quotes
- Is VAT in the price?
- How long the guarantee is
- Is the old sealant removed completely?
- Which colour the sealant will be
Windows and doors in Copthorne
Historic houses like Gravetye Manor (about 4.5 miles south-east) are a reminder that the area around Copthorne has older buildings as well as new. 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. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you let a flat or house near Gatwick Airport station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets. For an older house near a landmark such as St John's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Copthorne is about 3 miles north-east of Crawley, in West Sussex. If you need window mastic in Copthorne, it’s easy to get a quote: please phone 0345 464 0079 or email us. We are based in Crawley and cover West Sussex, Copthorne included. Copthorne is one of 371 places in West Sussex we cover.
Jobs for window mastic in RH10 and RH6 works the same way as everywhere else we cover. You’ll find streets such as Church Road, Brookside and Bridgelands, and we cover them all. Copthorne is on the A264, which makes it straightforward to reach. Neighbouring places we cover for window mastic include Shipley Bridge (1 mile north-west), Forge Wood (1 mile west), Tinsley Green (1 mile west), Burstow (1 mile north) and Keeper's Corner (1 mile north-east). Within a short drive, we also cover Crawley (3 miles south-west), Horsham (10 miles south-west), Haywards Heath (10 miles south), Burgess Hill (12 miles south), East Grinstead (5 miles east) and Broadfield (4 miles south-west).
What’s near Copthorne
Around Copthorne, our work takes us to homes and buildings near Worth Park Gardens, The Cherry Tree pub and Hazelwick School, among other places. Copthorne’s nearest station is Gatwick Airport station, about 2 miles north-west of the centre. Well-known places in the area include Effingham Park Motor Museum (1.6 miles east) and County Mall (3 miles south-west). Green spaces nearby include Hedgecourt Lake.
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
FAQs for Copthorne
Is Copthorne within the area you cover?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can you help a landlord with a rental near Gatwick Airport station?
Yes, rental work is part of what we do. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear quote.
How long before the joint can be used?
Cure times vary by product. We tell you how long to leave it before we go.
Which products do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
What does window mastic cost?
It depends on the job, so we quote each one individually. To get one, call 0345 464 0079 or drop us an email and let us know what needs doing and where.
Are you ARBOMaster approved?
Yes. We’re approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
Do you guarantee window mastic?
Yes. All our work carries a 12-month guarantee, and we are fully insured.
How many windows can you do in a day?
A few frames take a few hours, while a whole house takes longer. We confirm the timing with your quote.
When it isn’t the sealant
We will not take on work that will not last, so here’s what sealant cannot put right:
- Broken hinges, locks or handles
- Damp problems in the wall away from the window
- Rotten timber, which needs a joiner first
If you’re not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer.
Where we work in Copthorne
- Patio & French doors
- Composite doors
- uPVC windows
- Window sills
- Timber windows & doors
- Aluminium frames
Landlord and commercial work in Copthorne
If you manage several properties in or around Copthorne, jobs at different addresses can be quoted together. Send us the addresses and the work at each, and pictures by email help.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.