West Sussex · England
Copthorne External Mastic
Our applicators work in Copthorne on sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and a 12-month guarantee.
- Movement joints with cracked, split or missing sealant
- Moss and dirt in joints with no sealant left
- Old sealant gone brittle and cracked
External mastic in Copthorne
Low-level joints can normally be done from the ground. Where joints are higher up, tell us about the building when you get in touch and we will confirm what access is needed. We are often asked to deal with movement joints with cracked, split or missing sealant and joints where the bead has come unstuck, across render & cladding joints, joints between brick and frames and copings & trims.
Homes around Copthorne range from older cottages to newer houses, with walls and rooflines of every type. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
All our work comes with our 12-month guarantee.
- Place
- Copthorne (RH10, RH6)
- Region
- West Sussex
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Aftercare tips
Looking after new joints is easy, and it makes a real difference:
- Leave the joints unpainted unless we’ve said otherwise
- Clear growth from the base of walls and joints
- Deal with leaking gutters that soak the joints below
- Tell anyone working on the walls about the movement joints
If you have more work done on the wall, such as new render, cladding or an opening, show the contractor the movement joints. They must stay as flexible joints, never rendered or pointed over.
Act while the splits are small. At that stage it’s a simple cut out and reseal before water has had years to get in.
What external mastic looks like in Copthorne
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Gravetye Manor (about 4.5 miles south-east) nearby, there’s older building stock in the area around Copthorne as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth.
For landlords with property near Gatwick Airport station, outside joints that have cracked can let damp into a rental, so check them between lets. For an older house near a landmark such as St John's Church, an extension built onto an older house moves differently, and the joint between them takes the strain. For site and facilities teams at buildings such as Fairway Infant School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Copthorne is about 3 miles north-east of Crawley, in West Sussex. Every kind of property in Copthorne is covered for external mastic, old or new, large or small. The work is guaranteed for a year. Our West Sussex coverage runs to 371 places, and Copthorne is one of them.
Our applicators cover all of the RH10 and RH6 postcode area for external mastic and the streets around it. Whether your property is on Church Road, Brookside and Bridgelands or anywhere close by, our applicators can take on the job. Copthorne is on the A264, which makes it straightforward to reach. We also cover 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). We also work in nearby towns such as 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).
Near you in Copthorne
In Copthorne, that means homes and buildings near Worth Park Gardens, The Cherry Tree pub and Hazelwick School. The closest station to Copthorne is Gatwick Airport station, roughly 2 miles north-west. Other landmarks nearby include Effingham Park Motor Museum (1.6 miles east) and County Mall (3 miles south-west). The countryside around Copthorne includes Hedgecourt Lake.
Surface by surface
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. They’re resealed over backing rod with a low-modulus sealant in a colour to suit the brick.
Cladding and façade panels
Cladding and façade panels are normally separated by sealed joints. We reseal them with a sealant suited to the panel material.
Nearby places to Copthorne
What else we do in Copthorne
Can I do it myself?
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
A DIY attempt does not rule out a professional job. We remove it and do the joint properly, so just mention it when you contact us.
What affects the cost of external mastic
We quote each job individually. This is what makes a difference:
- Any mould that needs treating
- Which sealant suits the joint
- Whether the work is at height
- How much old sealant there is and how hard it is to remove
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we will explain the quote if you ask.
Helping us quote
To make quoting easier, let us know:
- Where the property is
- Roughly how big the job is
- What’s wrong with the joints now
- Whether it’s a home or a business
For a quick quote, get us on the phone, or email us if that’s easier. Describe what needs sealing and we’ll talk you through the work before giving you a price.
How the visit works
We keep the work tidy and contained to the area we’re working on, so you can carry on as normal. The job normally takes anything from a few hours to several days, depending on the building. For a job in Copthorne, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We start by checking each joint, agreeing the ones to redo and how we will reach them.
- The old mastic and anything lodged in the joint is removed.
- Both sides are cleaned back to sound material and primed if needed.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
How to prepare
- Tell us about any water getting in
- Mention any parking rules near the property
- On commercial sites, let us know about site rules
Getting a quote
Every job is quoted individually, so the first step is telling us about yours. Just ring 0345 464 0079 or drop us an email with the details.
Read more
Landlords, agents and businesses in Copthorne
For anyone letting property in or around Copthorne, several properties can be quoted together. Just tell us the addresses and what each one needs.
We work for letting agents and landlords as well as homeowners. Sealant work between tenants is a simple way to keep a property in good order before the next move-in.
When it isn’t the sealant
Before booking, it’s worth knowing the limits too:
- Walls that need new movement joints cut into them
- Rising or penetrating damp from elsewhere in the wall
- Failed render or damaged cladding panels
If you’re not sure, just call 0345 464 0079 or email us and we will give you a straight answer.
Where we work in Copthorne
- Render & cladding joints
- Concrete & block
- Brickwork movement joints
- Joints between brick and frames
- Copings & trims
- Façade panels
FAQs for Copthorne
Can you help a landlord with a rental near Gatwick Airport station?
Yes, landlords and agents are among the people we work for. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
Can you do external mastic in Copthorne?
Yes, Copthorne is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or drop us an email and tell us what needs doing.
Do you take out the old sealant first?
Yes. All of the old material is cut out and the joint cleaned.
What is backing rod for?
Backing rod controls the sealant depth and keeps it off the back of the joint. That way it bonds to the two sides only and can stretch.
Can you quote for more than one area?
Of course. Combining jobs makes good use of the visit.
Can you seal joints between two different materials?
Yes. Different materials move at different rates, so a flexible sealant is needed where they meet. The sealant is matched to both sides.
Where is Mr Mastic based?
We work from Crawley. Our applicators cover Copthorne.
How do you reach high-level joints?
That depends on the building and the joints. Where joints can be reached safely, we’ll do them. Give us some details and we will confirm the access.