Kent · England
External Mastic in Coxheath
External mastic for Coxheath, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Movement joints filled with mortar instead of sealant
- Hard, crazed mastic that has stopped moving
- Weeds or debris growing in open joints
How the job changes by surface
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. We seal the joint with a flexible exterior sealant so neither cracks the other.
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. The movement joint takes that up, so its sealant has to stay flexible.
How we handle external mastic in Coxheath
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant in a matching colour. If you are dealing with movement joints with cracked, split or missing sealant and sealant pulling away from one side of the joint, we can help.
Around Coxheath, garages, outbuildings and extensions all add to the joints on the outside of a home. Gutter ends, garage door frames and the joints where an extension meets the house are typical spots for leaks.
Whatever the size of the job, you get the same one-year guarantee in Coxheath and across Kent.
- Where
- Coxheath (ME17, ME15)
- Wider area
- Kent
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Aftercare tips
A little care helps the new joints last. Our advice:
- Ask before painting over external sealant
- Act on the first splits you see
- Keep water from gutters off the wall
- Tell anyone working on the walls about the movement joints
Follow the cure time we give you before the joint is knocked or disturbed. The surface skins over quickly, but full cure takes longer.
Act while the splits are small. Then it’s a straightforward cut-out and reseal.
Signs you need external mastic in Coxheath
Every building moves. Brickwork grows a little over the years, blockwork and concrete shrink, and all of it moves with heat and moisture. All of that ends up in the joint sealant.
Any of these means the joints need attention:
- Joints with sealant missing in places
- Sealant that has lost its bond to the brick or render
- Joints pointed up with cement by mistake
- Hard, crazed mastic that has stopped moving
Homes close to Holy Trinity Church include some older properties, and the joints between older walls, newer extensions and the roofline need a sealant that can move.
Comparing quotes
- Who turns up on the day
- Whether you can choose the colour
- What the quote includes, VAT included or not
- How long the guarantee is
What we cannot put right
It helps to know what we cannot do too:
- Movement that is more than a sealant joint can take
- Cracked brickwork or render that needs a builder or plasterer
- Adding movement joints to masonry that has none
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think before booking.
Surfaces we seal
- Joints between brick and frames
- Brickwork movement joints
- Façade panels
- Render & cladding joints
- Concrete & block
- Copings & trims
Towns and villages near Coxheath
Also in Coxheath
What affects the cost of external mastic
The quote reflects the job in front of us. We look at:
- The product the joint needs
- The size of the job
- How many rooms, windows or areas are involved
- Access and height
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
What to tell us for a quote
To help us quote quickly, let us know:
- Whether it’s a home or a business
- Access, such as stairs, a lift or height
- Whether it has been sealed before
- The rough size of the job
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints.
Common questions in Coxheath
Is Coxheath in your area for external mastic?
Yes, Coxheath is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or email us and tell us what needs doing.
Do you work for landlords with property near East Farleigh station?
Yes. We work for letting agents and landlords as well as householders. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear price.
Do you have insurance?
Yes. Mr Mastic is fully insured.
Is there any odour?
That depends on the sealant. Some products have a noticeable smell, others very little, and any smell fades as they cure.
When will the joints need doing again?
That depends on the wall, the weather and the movement. Signs to watch for are cracking, hardening and gaps at the edges and have them redone then.
What is a movement joint?
A vertical gap in a long brick wall is normally a movement joint. It gives the wall room to move, and it should be sealed with a flexible sealant.
Is it messy?
We keep the work tidy. We protect what’s around the joints, and the area is left clean when we finish.
Where do you work from?
Our base is Crawley, with over 20 years’ experience. We work across South East England, London and Scotland.
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 chosen for how the joint moves and where it is, and the work is guaranteed for a year.
A DIY attempt does not rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
What external mastic looks like in Coxheath
With historic houses such as Stoneacre (about 3.7 miles east) nearby, there’s older building stock in the area around Coxheath as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you look after a building such as Coxheath Primary School, larger buildings have long runs of movement joint that eventually need resealing. Rented homes near East Farleigh station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets.
Coxheath is about 3 miles south-west of Maidstone, in Kent. Across the ME17 area, we can carry out external mastic at your property. Coxheath is one of 922 places in Kent where we work. There’s also a page for London, about 31 miles away.
Jobs for external mastic in ME17 and ME15 works the same way as everywhere else we cover. Local streets include Westway, Stockett Lane and Orchard Close. Neighbouring places we cover for external mastic include Dean Street (1 mile north), East Farleigh (1 mile north-west), Farleigh Green (2 miles north-west), Kettle Corner (2 miles north-west) and Hunton (2 miles south-west). Further out, we also cover Maidstone (3 miles north-east), Sittingbourne (13 miles north-east), Sevenoaks (14 miles west), Royal Tunbridge Wells (12 miles south-west), Gravesend (14 miles north) and Tonbridge (10 miles west).
Around Coxheath
Locally, jobs take us to homes and businesses close to The Horse Shoes Public House, Cornwallis Academy and Quarry Wood. The nearest railway station is East Farleigh station, roughly 1.5 miles north. Well-known places in the area include The Mall Maidstone (3 miles north-east) and Oakwood Hospital (2.4 miles north).
What we do, step by step
Once we are on site, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. After that, the work takes a few hours to a few days, depending on the length of joint and the access. For a job in Coxheath, 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.
- 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.
- We gun in low-modulus sealant and tool it neatly.
Preparing for the visit
- Mention any parking rules near the property
- Clear items away from the joints we’re working on
- Tell us about any water getting in
Getting a quote
We quote each job on its own. Simply ring 0345 464 0079 or email us and describe the job and send photos if you have them.