West Sussex · England
Sharpthorne External Mastic
External mastic for Sharpthorne and the surrounding area: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Rigid filler in a joint that should flex
- Leaking joints around cladding and façade panels
- Failed seals between different materials
FAQs for Sharpthorne
Will you come out to Sharpthorne?
Yes, we do. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Do you cover Sharpthorne for external mastic?
Yes. We work across London and the South East, and Sharpthorne is part of that. You can call 0345 464 0079 or email us and tell us what needs doing.
Are you an approved applicator?
Yes. Mr Mastic is an ARBOMaster approved applicator, and we’re fully insured.
Do you work for letting agents?
Yes. As well as homeowners, we work for landlords, agents, businesses and hotels in Sharpthorne.
Do the sealants smell?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
I rent my home. Can I book you?
We’re happy to deal with the tenant, landlord or agent. Just make sure your landlord agrees.
Are you fully insured?
Yes. Full insurance covers our work.
Can you reach joints on upper floors?
That depends on how high the joints are and the ground below. Low-level joints are straightforward; for higher work, tell us about the building and we will confirm what’s needed.
External mastic in Sharpthorne, done properly
We are ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Porous or awkward surfaces are primed where the sealant needs it and we use one wherever it does. We are often asked to deal with panel joints letting water in and movement joints filled with mortar instead of sealant, on brickwork movement joints, copings & trims and façade panels.
Somewhere as small as Sharpthorne, homes and farm buildings often face open ground, where walls and rooflines take the weather head on. Joints on those walls need a sealant that moves with the building and stays in place.
Your job is guaranteed for a year, as with all our work.
- Where
- Sharpthorne (RH19)
- Wider area
- West Sussex
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Towns and villages near Sharpthorne
What else we do in Sharpthorne
What happens on the day
There’s no need to move everything out before we come, only the area right around the joints. We protect the rest, and the job takes anything from a few hours to several days, depending on the building for a typical job. In a small place like Sharpthorne, access is generally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Preparing for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Mention any tricky access
- Tell us about any previous sealing or DIY attempts
Ask for a quote
We quote each job on its own, so the first step is telling us about yours. Simply phone 0345 464 0079 or send us an email and describe the job.
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Landlords, agents and businesses in Sharpthorne
In hotels, rooms out of use cost money, so we plan the work room by room. We have worked in hotels as well as homes and businesses.
Landlords and agents in Sharpthorne can book us as well as homeowners. Sealant work between tenants is a simple way to keep a property in good order before the next move-in.
Signs you need external mastic in Sharpthorne
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
The most common problems we see are:
- Sealant pulling away from one side of the joint
- Brick movement joints where the sealant has split
- Movement joints filled with mortar instead of sealant
- Failed seals between different materials
Rented homes near East Grinstead station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Questions to ask before you book
- Whether all the old sealant comes out first
- What happens if they find a problem under the old sealant
- Whether they’re fully insured
- How much experience the applicator has
External mastic in Sharpthorne: local notes
Historic houses like Priest House (about 0.5 miles west) are a reminder that the area around Sharpthorne has older buildings as well as new. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
In the older streets around St Margaret's Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Schools such as West Hoathly CofE Primary School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s.
Sharpthorne is about 4 miles south of East Grinstead, in West Sussex. We carry out external mastic for householders, landlords and businesses in Sharpthorne and nearby. Our area takes in 371 places across West Sussex, large and small. Our Crawley page covers work nearby, about 7 miles away.
Work in RH19 is quoted and booked the same way as anywhere else. We cover properties on Station Road, Marlpit Road and Bayhams Field. We also cover West Hoathly (1 mile west), Highbrook (2 miles south), Selsfield Common (2 miles north-west), Little London (2 miles south-west) and Birchgrove (3 miles south-east). Within a short drive, we also cover Crawley (7 miles west), Horsham (12 miles west), Haywards Heath (6 miles south-west), Burgess Hill (9 miles south-west), East Grinstead (4 miles north) and Broadfield (7 miles west).
What’s near Sharpthorne
We work in homes and buildings around The Fox pub, among other places. The closest station to Sharpthorne is East Grinstead station, roughly 3.6 miles north of the centre. Well-known places in the area include Waterbury Castle (2.6 miles south) and East Grinstead Museum (3.7 miles north-east). Green spaces nearby include Hedgecourt Lake.
Why act early in Sharpthorne
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That protects surfaces like brick, render and concrete. A stiffer product can damage the joint edge as it fails. Where a wall is exposed, as many are in small places like Sharpthorne, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
Why Sharpthorne clients choose us
- Quality sealants from Arbo and Everbuild
- Anti-fungal sanitary silicone in wet areas
- We never seal over old sealant
- 20+ years of sealant experience
How the job changes by surface
Render joints
Render has movement joints and stop beads that need sealing. We reseal them with a flexible exterior sealant that suits the render colour.
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. We cut out the old sealant and reseal with a product suited to both surfaces.
Looking after it afterwards
So the new joints stay in good condition:
- Check the sealant is paintable before painting near it
- Get split or bare joints resealed while the damage is small
- Look over the joints every year, ideally after winter
- Avoid pressure-washing directly into sealant joints
Don’t paint over the new sealant unless we have said the product is paintable. Paint can crack on a flexible joint and spoil the finish.
Water getting behind cladding or render can go unnoticed for a long time. By the time there’s a damp patch, the damage can be well established, so it’s worth resealing at the first signs.
DIY versus a professional finish
If you’re set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.