Kent · England
Dunk's Green External Mastic
Specialist external mastic for Dunk's Green: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Sealant that has lost its bond to the brick or render
- Old sealant gone brittle and cracked
- Joints pointed up with cement by mistake
Questions from Dunk's Green
Is Dunk's Green in your area for external mastic?
Yes, Dunk's Green is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or drop us an email and tell us what needs doing.
I let a flat near Borough Green & Wrotham station. Can you help?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before work begins.
Will there be a smell?
That depends on the sealant. Some products have a noticeable smell, others very little, and any smell fades as they cure.
Do you work at height?
It depends on the height and the site. Ground-floor joints are simple; for higher work, tell us about the building and we’ll confirm what’s needed.
Do you remove the old sealant?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Do you seal joints where cladding meets other materials?
Yes. Joints between dissimilar materials are a big part of external work. We use a flexible sealant suited to both surfaces, primed where needed.
How long before the joint can be used?
Most sealants are touch-dry well before they’re fully cured. We will tell you how long to leave the joint.
Is it worth trying it myself?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
External mastic in Dunk's Green
On houses, flats and commercial buildings across Dunk's Green, we reseal joints in brickwork, render, cladding and façade panels. Every joint gets the same careful preparation: clean joint faces and the right depth. If you are dealing with sealant that has lost its bond to the brick or render and joints with sealant missing in places, we can help.
Outside joints can only be sealed when they’re dry, so work in Dunk's Green is booked around the forecast. Let us know about access to every wall, plus any garages or outbuildings.
There’s a 12-month guarantee on every job.
- Where
- Dunk's Green (TN11)
- Region
- Kent
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Dunk's Green buildings and the weather
The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Old Soar Manor (about 0.9 miles north-east) are a reminder that the area around Dunk's Green 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.
Letting a property close to Borough Green & Wrotham station? Then split movement joints are easy to miss on a rental until damp shows inside. For an older house near a landmark such as Plaxtol Church, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Dunk's Green is about 4 miles north of Tonbridge, in Kent. Homes, rented property, offices and hotels in Dunk's Green is covered for external mastic, old or new, large or small. The work is guaranteed for a year. 922 places in Kent are on our list. Our London page covers work nearby.
Postcode districts we cover here for external mastic: TN11. If you are just outside Dunk's Green, we cover Plaxtol (1 mile north), Roughway (1 mile east), Claygate Cross (2 miles north), Crouch (2 miles north) and Pittswood (2 miles south). Within a short drive, we also cover Maidstone (10 miles east), Dartford (14 miles north), Sevenoaks (6 miles west), Royal Tunbridge Wells (8 miles south), Gravesend (13 miles north) and Tonbridge (4 miles south).
Local landmarks in Dunk's Green
Around Dunk's Green, our work takes us to homes and buildings near Hadlow Rural Community School, The Kentish Rifleman Public House and Ivy Hatch Nature Reserve, among other places. The closest station to Dunk's Green is Borough Green & Wrotham station, roughly 2.8 miles north of the centre. Nearby you’ll also find Tonbridge Cottage Hospital (5.3 miles south) and Ightham Court (3.1 miles north). Green spaces nearby include Barden Lake.
Why act early in Dunk's Green
A properly done movement joint is an even line in a colour that suits the wall. A hurried job with smeared edges and no backing looks worse and fails sooner so it’s worth doing right. In a small place like Dunk's Green, homes can be exposed to wind and rain, which finds any gap, and damp in older walls is slow to dry out.
Doing several joints on one visit is usually more efficient than separate visits. You’ll get one clear quote for the whole job.
Why us?
- Arbo and Everbuild products
- White, clear, grey or coloured to suit, where the product allows
- Domestic, commercial and hotel work
- 4.9 on Google from 180+ five-star reviews
See our cost guide or our reviews.
Landlords, agents and businesses in Dunk's Green
We also work for property managers and facilities teams in Dunk's Green and across Kent. We can quote a run of properties together, and we’re fully insured for the work.
Hotels need rooms back in use, so we plan the work room by room around your bookings where we can. We have worked in hotels as well as homes and businesses.
Should I try it myself first?
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
Other services in Dunk's Green
Do you need external mastic in Dunk's Green?
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 sealant never bonds properly.
People generally contact us after spotting something like this:
- Brick movement joints where the sealant has split
- Joints pointed up with cement by mistake
- Failed seals between different materials
- Water getting into walls through failed joints
For site and facilities teams at buildings such as Plaxtol Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
What your quote should include
- Which sealant they’ll use, and why
- What insurance they hold
- Whether VAT is included
- Whether they seal over old material or remove it
How the visit works
We keep the work tidy and contained to the joints we’re treating, so you can carry on as normal. Expect the work to take anything from a few hours to several days, depending on the building. In a small place like Dunk's Green, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- We cut out the failed sealant and rake out any dirt or growth.
- We clean both faces of the joint and prime them where the product calls for it.
- 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 access, such as stairs, a lift or high-level joints
- Tell us if parking is tricky
- Tell us about any previous sealing or DIY attempts
How to get a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints.
Related advice
How the job changes 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.
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
Keeping the joints in good condition
So the new joints stay in good condition:
- Clear growth from the base of walls and joints
- Keep water from gutters off the wall
- Look over the joints every year, ideally after winter
- Ask before painting over external sealant
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.