Medway · England
External Mastic in Capstone
External mastic in Capstone from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Rigid filler in a joint that should flex
- Brick movement joints where the sealant has split
- Failed seals between different materials
External mastic in Capstone
Joints in render and cladding are easy to overlook until a damp patch appears. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product in a colour to suit. We are often asked to deal with cracked joints where brick meets render or frames and damp patches traced to an open external joint, on concrete & block, joints between brick and frames and façade panels.
Older homes in small places like Capstone may be stone, brick or timber-framed, often with later extensions. The joints where those materials meet are the weak points, and they need the right sealant at the right depth.
We stand behind the work with a 12-month guarantee, so you are not left on your own once the job is done.
- Place
- Capstone (ME7)
- Region
- Medway
- Cover
- A year, on every job
- Quote
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What external mastic looks like in Capstone
Capstone is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. With historic houses such as Restoration House (about 3.1 miles north-west) nearby, there’s older building stock in the area around Capstone 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 site and facilities teams at buildings such as Hempstead Infant School, its movement joints, gutters and trims need looking after like any other building’s. Letting a property close to Gillingham (Kent) station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Capstone is about 1 mile south-west of Gillingham, in Medway. From the centre of Capstone to the outskirts, we cover external mastic for every kind of property, from flats and houses to offices and hotels. Our Medway coverage runs to 68 places, Capstone among them. You can also see our page for Chelmsford, roughly 26 miles from Capstone.
We work across ME7 for external mastic and the streets around it. Other places close to Capstone include Darland (1 mile north), Hale (1 mile north-west), Hempstead (1 mile south-east), Gillingham (1 mile north-east) and Chatham (1 mile west). We also work in nearby towns such as Rochester (4 miles north-west), Strood (4 miles north-west), Hoo St Werburgh (5 miles north), Rochester Riverside (3 miles north-west), Peters Village (4 miles west) and Brompton (3 miles north-west).
Landmarks near Capstone
We work in homes and buildings around Chatham Grammar School for Girls, The Star pub and The Robert Napier School. The nearest railway station is Gillingham (Kent) station, roughly 2 miles north of the centre. Well-known places in the area include Medway Maritime Hospital (1.7 miles north-west) and Pentagon Shopping Centre (2.3 miles north-west). Not far away are Burham Down and Blue Bell Hill.
Capstone: your questions answered
Can you help a landlord with a rental near Gillingham (Kent) station?
Yes, landlords and agents are among the people we work for. Just call 0345 464 0079 or drop us an email with the address and what needs doing, and we will send you a clear quote.
Does the coastal weather in Capstone affect outside sealant?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
How long will you be here?
As a guide, most jobs take a few hours to a few days, depending on the length of joint and the access. Larger jobs naturally take longer.
Can you seal over the old sealant?
No, and we never do. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
What is backing rod for?
We fit closed-cell backing rod wherever the joint depth needs controlling. It sets the sealant depth and prevents three-sided bonding so the bead can stretch.
Can I do it myself?
You can, for simple jobs. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
Do you come to Capstone?
Yes. From our base in Crawley, we cover South East England, London and all of Scotland, and that includes Capstone.
Will the old sealant be removed?
Always. Sealing over the old bead is the commonest cause of early failure, so we never do it.
What we are called out for in Capstone
A lot of failed joints come down to preparation: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
If you can see any of these, it’s time to have the joints looked at:
- Panel joints letting water in
- Movement joints filled with mortar instead of sealant
- Joints with sealant missing in places
- Sealant pulling away from one side of the joint
For an older house near a landmark such as All Saints Church, older walls, gutters and the joints where extensions meet them need a flexible sealant.
What to look for in a quote
- Whether all the old sealant comes out first
- Whether they’re fully insured
- What happens if they find a problem under the old sealant
- Is VAT in the price?
What the job involves on each surface
Copings and trims
Coping joints that leak let water straight down into the wall. Sealing them early saves the wall below.
Cladding and façade panels
If the façade has a specified sealant, that’s what we use, or one the system allows. Tell us what the building has when you get in touch.
What we cannot put right
Some problems need a builder, plumber or other trade rather than us:
- Adding movement joints to masonry that has none
- Cracking across the wall rather than at a joint
- Failed render or damaged cladding panels
If you’re not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer.
What we seal
- Joints between brick and frames
- Façade panels
- Render & cladding joints
- Brickwork movement joints
- Copings & trims
- Concrete & block
Other services in Capstone
How the visit works
We keep the work tidy and contained to the joints we’re treating, so you can carry on as normal. The job generally takes a few hours to a few days, depending on the length of joint and the access. Somewhere like Capstone needs a little journey planning: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Clear the area around the work
- Let us know about earlier repairs to the joints
- Mention any parking rules near the property
Get a quote
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and email photos if that is easy.
Related advice
Keeping the joints in good condition
Simple care keeps the joints in good condition. Our advice:
- Get split or bare joints resealed while the damage is small
- Check the sealant is paintable before painting near it
- Point out the joints to other trades
- Check external joints each spring
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.
A joint that has stopped moving pushes the movement elsewhere, often as cracks near the joint. Catch it early and you reduce the risk.
DIY sealant or a professional job?
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Landlords, agents and businesses in Capstone
Mouldy or split sealant often shows up at the end of a tenancy. We can quote for more than one property at once.
In hotels, rooms out of use cost money, so we plan the work room by room. We’ve worked in hotels as well as homes and businesses.