Kent · England
External Mastic in Dunton Green
We cover Dunton Green for sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and a one-year guarantee.
- Moss and dirt in joints with no sealant left
- Rigid filler in a joint that should flex
- Brick movement joints where the sealant has split
External mastic for homes and businesses in Dunton Green
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product in a matching colour. If you have rain getting behind render or cladding at a joint and weeds or debris growing in open joints, we can put it right, whatever the surface.
In a village or hamlet like Dunton Green, older cottages and farm buildings often stand in the open, 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.
Big or small, you get the same one-year guarantee in Dunton Green and across Kent.
- Location
- Dunton Green (TN13, TN14)
- Region
- Kent
- Guarantee
- 12 months on all our work
- Quote
- A clear price before we start
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Why deal with it now?
Running new sealant over the old bead rarely lasts. The new layer can’t bond properly to old, weathered material, so we always take the old sealant out. Older cottages and farmhouses around Dunton Green can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Leaving a failed joint usually makes the job bigger, not smaller, as water and mould keep getting in. If you’re not sure whether it needs doing, ring 0345 464 0079 or email us for an honest opinion and a quote.
Why choose Mr Mastic in Dunton Green
- Approved under the ARBOMaster scheme
- Over 20 years’ experience
- One-year guarantee on every job
- Anti-fungal silicone where joints get wet
When something else is needed
We’d rather tell you now than do work that will not last, so here’s what sealant cannot put right:
- Structural movement, which needs a surveyor or engineer
- Rising or penetrating damp from elsewhere in the wall
- Loose or hollow render, which needs re-rendering
If in doubt, call 0345 464 0079 or send us an email and we will say what we think before you book.
Where we work in Dunton Green
- Joints between brick and frames
- Façade panels
- Concrete & block
- Render & cladding joints
- Copings & trims
- Brickwork movement joints
External mastic in Dunton Green: local notes
With historic houses such as Knole House (about 2.5 miles south-east) nearby, there’s older building stock in the area around Dunton Green 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. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you live in an older home near St John's Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Letting a property close to Dunton Green station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Dunton Green is about 1 mile north-west of Sevenoaks, in Kent. Anywhere in TN13, we can carry out external mastic at your property. Dunton Green is one of 922 places in Kent we cover. You can also see our page for London, about 18 miles away.
Every address in TN13 and TN14 is covered for external mastic. We cover properties on Station Road, Campion Square and London Road and the roads around them. Nearby, we also carry out external mastic in Riverhead (1 mile south), Chipstead (1 mile south-west), Bessels Green (1 mile south-west), Sevenoaks (1 mile south-east) and Chevening (2 miles west). Within a short drive, we also cover Dartford (11 miles north), Royal Tunbridge Wells (12 miles south), Gravesend (13 miles north-east), Tonbridge (8 miles south-east), Northfleet (12 miles north-east) and Swanley (7 miles north).
What’s near Dunton Green
Around Dunton Green, our work takes us to homes and buildings near Montreal Park, The Miners Arms and Trinity School and the streets around them. There’s a railway station in Dunton Green itself: Dunton Green station. Nearby you’ll also find Otford Heritage Centre (1.5 miles north-east) and Kemsing Castle Bank (2.8 miles east). The countryside around Dunton Green includes Dryhill Nature Reserve and Betsom's Hill.
Places near Dunton Green
More services for Dunton Green
When to call us in Dunton Green
Buildings move more than people expect. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
Keep an eye out for any of the following:
- Movement joints filled with mortar instead of sealant
- Panel joints letting water in
- Sealant that has lost its bond to the brick or render
- Moss and dirt in joints with no sealant left
Schools such as Dunton Green Primary School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing.
What to look for in a quote
- What guarantee comes with the work
- How the surfaces are prepared before sealing
- How hidden problems are handled
- Whether you can choose the colour
Dunton Green: your questions answered
I let a flat near Dunton Green station. Can you help?
Yes, rental work is part of what we do. 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.
Is Dunton Green in your area for external mastic?
Yes, Dunton Green is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or send us an email and let us know what needs doing.
Can you quote for more than one area?
Yes, we can. More than one area can be quoted together.
Will you leave a mess?
No. We work neatly, protect the area around the joints and tidy up afterwards.
How long does external mastic take?
A typical job takes anything from a few hours to several days, depending on the building, including preparation and clearing up. Your quote will say how long we expect yours to take.
Will the new joint stand out?
We aim for a joint that suits the wall rather than one that jumps out. We will talk through colour options before any work starts, matched as closely as the range allows.
Do you guarantee your work?
Yes. All our work carries our one-year guarantee.
Can you seal over the old sealant?
No. Fresh sealant doesn’t stick to old sealant, and it traps any mould or water underneath. We remove it all first.
How it works
Most of a good job is in the preparation, and we don’t rush it. Joints are cleaned back and dried before anything new goes in. All told, the work takes anything from a few hours to several days, depending on the building. For a village or hamlet like Dunton Green, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- First we look over the joints with you, agree which to renew and talk through access.
- Old sealant and any debris are cut and raked out.
- The joint faces are cleaned and primed where the sealant needs it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- Let us know about stairs, lifts or work at height
- On commercial sites, let us know about site rules
- Try not to wet indoor joints just before the visit
How to get a quote
For external mastic in Dunton Green, ring 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and you’ll get a clear quote before any work starts.
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What the job involves on each surface
Copings and trims
Coping and trim joints face rain and sun head on. We reseal them with an exterior sealant suited to the material.
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. We reseal their joints with backing rod and a flexible product.
How to look after the new joints
A little care helps the new joints last. We recommend:
- Tell anyone working on the walls about the movement joints
- Act on the first splits you see
- Check the sealant is paintable before painting near it
- Fix overflowing gutters above sealed joints
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
Small splits are the time to act. At that stage it’s a simple cut out and reseal.