Kent · England
External Mastic in Gravel Castle
Our applicators work in Gravel Castle on sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly.
- Joints pointed up with cement by mistake
- Plants rooting in failed movement joints
- Failed sealant between panels on a façade
External mastic for homes and businesses in Gravel Castle
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. We pick a colour that sits well with the wall. We work on brickwork movement joints, façade panels and render & cladding joints, and common reasons people get in touch are leaking joints around cladding and façade panels and damp patches traced to an open external joint.
External sealant needs dry, clean surfaces, so work around Gravel Castle is planned for dry weather. Tell us about access to all sides of the building, including outbuildings and garages.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Place
- Gravel Castle (CT4)
- Wider area
- Kent
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What happens if it’s left?
Water gets in through a failed movement joint, behind render and cladding. Resealing early keeps the job to the joint itself, rather than the wall around it. In a small place like Gravel Castle, homes can be exposed to wind and rain, which finds any gap, and damp in older walls is slow to dry out.
Rather than a set price list, we look at what your job involves: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
Why choose Mr Mastic in Gravel Castle
- A sealant colour to suit the surroundings
- Arbo and Everbuild products
- Old sealant always removed completely
- More than 20 years in sealant work
Take a look at what affects the cost and customer reviews.
Looking after it afterwards
To keep the joints looking good and working properly:
- Ask before painting over external sealant
- Keep movement joints as flexible joints, not mortar
- Keep high-pressure jets off the joints
- Clear growth from the base of walls and joints
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
An open movement joint lets rain into the wall every time it pours. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.
Nearby places to Gravel Castle
Also in Gravel Castle
Work for landlords, hotels and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
How the visit works
We keep the work tidy and contained to the area we are working on, so you can carry on as normal. Expect the work to take a few hours for a handful of joints, longer for a whole elevation. In a small place like Gravel Castle, access is generally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- We start by walking round the building and agreeing the joints and the access.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Mention any tricky access
- Move anything stored near the joints
- Tell us about any water getting in
Getting a quote
If you are in Gravel Castle and need external mastic, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and we will agree the price before any work begins.
Advice
Common problems we fix in Gravel Castle
Sometimes a movement joint was filled with mortar or a rigid filler, often by someone who didn’t know what it was for. The joint cannot move, so the wall cracks somewhere else instead.
Signs it’s time to call us include:
- Joints pointed up with cement by mistake
- Damp patches traced to an open external joint
- Moss and dirt in joints with no sealant left
- Failed sealant between panels on a façade
Letting a property close to Snowdown station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies.
What your quote should include
- Whether they’re fully insured
- Whether the sealant suits the joint
- Who turns up on the day
- Whether VAT is included
Gravel Castle buildings and the weather
Historic houses like Goodnestone Park (about 3.8 miles north-east) are a reminder that the area around Gravel Castle has older buildings as well as new. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. 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 Church of St John the Baptist, 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 Barham Church of England Primary School, larger buildings have long runs of movement joint that eventually need resealing.
Gravel Castle is about 6 miles south-east of Canterbury, in Kent. If you need external mastic in Gravel Castle, it’s easy to get a quote: please phone 0345 464 0079 or send us an email. We are based in Crawley and cover Kent, Gravel Castle included. Our Kent coverage runs to 922 places, Gravel Castle among them. There’s also a page for Chelmsford, about 47 miles away.
We work across the CT4 postcode area for external mastic. Whether your property is on Gravel Castle Road and Church Lane or anywhere close by, our applicators can take on the job. If you are just outside Gravel Castle, we cover Barham (1 mile north-west), Derringstone (1 mile west), Heart's Delight (1 mile west), Out Elmstead (1 mile north-west) and Womenswold (1 mile north-east). Within a short drive, we also cover Ashford (14 miles west), Canterbury (6 miles north-west), Margate (15 miles north-east), Dover (7 miles south-east), Folkestone (8 miles south) and Ramsgate (14 miles north-east).
What’s near Gravel Castle
In Gravel Castle, that means homes and buildings near Jumping Downs. The closest station to Gravel Castle is Snowdown station, roughly 2.2 miles east of the centre. Other landmarks nearby include Kent and Canterbury Hospital (5.5 miles north-west).
Should I try it myself first?
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Honest limits
Some problems need a builder, plumber or other trade rather than us:
- Rising or penetrating damp from elsewhere in the wall
- Loose or hollow render, which needs re-rendering
- Cutting new joints into brickwork, which is building work rather than sealant work
If you’re not sure, just ring 0345 464 0079 or drop us an email and we will give you a straight answer before you book.
Joints and surfaces we work on
- Copings & trims
- Brickwork movement joints
- Render & cladding joints
- Joints between brick and frames
- Façade panels
- Concrete & block
Gravel Castle questions
Will you come out to Gravel Castle?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
I let a flat near Snowdown station. Can you help?
Yes, we work for landlords and agents. You can call 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Where is Mr Mastic based?
Our base is Crawley. Our area covers South East England, London and Scotland.
Can you reach joints on upper floors?
Each building is different. Tell us the height, the number of joints and what’s below them, and we will confirm what access is needed.
What do you put in the joint?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We’ll tell you what we are using and why.
Do you guarantee your work?
Yes, always. There’s a 12-month guarantee on every job, large or small.
Can you seal over the old sealant?
No. New silicone will not bond to old silicone, and anything trapped underneath, including mould and water, stays there. We remove it all first.
Will the new joint stand out?
Exterior sealants are made in a range of colours, from greys and browns to whites and stone shades. We pick the one that suits your wall best so it does not stand out.