Kent · England
External & façade joints in Stone, Kent
External mastic in Stone from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Rain getting behind render or cladding at a joint
- Failed sealant between panels on a façade
- Weeds or debris growing in open joints
About our external mastic in Stone
External mastic is a job where short cuts show quickly. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We take the old material out and do it properly. If you have damp patches traced to an open external joint and gaps where render, brick and frames meet, we can help.
Around Stone, 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.
A one-year guarantee comes as standard.
- Where
- Stone (DA9)
- Region
- Kent
- Cover
- A year, on every job
- Price
- A clear price before work begins
- Call
- 0345 464 0079
- Updated
- 26 October 2026
What the job involves on each surface
Copings and trims
A failed coping joint lets water into the top of the wall. Sealing them early saves the wall below.
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. A flexible sealant bridges the two.
What affects the cost of external mastic
The quote reflects the job in front of us. We take into account:
- How much there is to do
- Which sealant suits the joint
- Working hours on commercial sites
- Mould in or behind the old joints
What you pay reflects the work, not a rough estimate. That’s why we ask a few questions first.
What to tell us for a quote
Photos by email are helpful but not essential. Please mention:
- Where the property is
- Pictures of the joints, sent by email
- The rough size of the job
- How we’d reach the joints
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is. When it suits you, phone 0345 464 0079 or email us.
What happens if it’s left?
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That matters on brick, render and concrete, which can be weaker at the face. A stiffer product can damage the joint edge as it fails. Homes in smaller places like Stone can face more weather, and failed outside joints let damp into walls. Indoors, a failed seal lets water into floors and panels as it would anywhere.
Instead of a standard rate, we look at what your job involves: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Why book with us
- Quality sealants from Arbo and Everbuild
- Old sealant always removed completely
- Domestic, commercial and hotel work
- Rated 4.9 stars on Google
Read our cost guide or our reviews.
Stone: your questions answered
Is Stone in your area for external mastic?
Yes, Stone is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job.
Do you cover smaller places like Stone?
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.
Will you leave a mess?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
Can tenants book the work?
Of course. Ask your landlord first, and we can send them the quote if that helps.
When is the sealant fully cured?
That depends on the sealant used, so please follow the time we give you.
Do you remove the old sealant?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Why do you put foam in the joint first?
Backing rod controls the sealant depth and keeps it off the back of the joint. Then the sealant bonds to two faces and can move.
Do you work for landlords and businesses?
Yes. We work for householders, landlords, letting agents, businesses and hotels in Stone.
DIY versus a professional finish
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What external mastic looks like in Stone
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. With historic houses such as Hall Place and Gardens (about 4.8 miles west) nearby, there’s older building stock in the area around Stone 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.
If you let a flat or house near Stone Crossing station, outside joints that have cracked can let damp into a rental, so check them between lets. If you look after a building such as Stone St Mary's CofE Primary School, its movement joints, gutters and trims need looking after like any other building’s.
Stone is about 2 miles east of Dartford, in Kent. Stone gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Stone is one of 922 towns and villages in Kent where we work for external mastic. You can also see our page for London, roughly 16 miles from Stone.
Jobs for external mastic in DA9 works the same way as everywhere else we cover. Local streets include Church Road, Perkins Close and Richardson Close, and we cover them all. You will find Stone on the A296, so it’s easy for us to get to with everything needed for external mastic. Other places close to Stone include Greenhithe (1 mile north-east), Swanscombe (1 mile east), Bean (2 miles south-east), Darenth (2 miles south) and Temple Hill (2 miles west). Within a short drive, we also cover Sevenoaks (12 miles south), Gravesend (5 miles east), Northfleet (3 miles east), Swanley (5 miles south-west), Kings Hill (13 miles south-east) and Windmill Hill (4 miles east).
What’s near Stone
Around Stone, our work takes us to homes and buildings near Darenth Country Park, The White Hart Public House and Stone Lodge School. For rail, the closest station is Stone Crossing station, about 0.5 miles north-west. Well-known places in the area include Stone Museum of Geology (1.3 miles west) and Darent Valley Hospital (1 mile south-west). For a walk, there’s Chafford Gorges Nature Park and Sawyers Lake.
How it works
We bring everything the job needs with us, so you don’t need to buy or prepare anything. Once we’ve agreed what’s being done, we protect the area and start. It normally takes a few hours to a few days, depending on the length of joint and the access. For a job in Stone, 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.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- 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.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Let us know if you’ve seen damp or leaks
- Mention if the joints have been sealed before
Get a quote
Getting a quote is simple: let us know what needs doing and where. Photos by email help us understand the job, and we’ll come back to you with a quote.
Read more
Signs you need external mastic in Stone
UV, rain and frost all age exterior sealant. Over the years it hardens, cracks on the surface and loses its give, so the joint eventually tears or comes away from one side.
Signs it’s time to call us include:
- Leaking joints around cladding and façade panels
- Movement joints with cracked, split or missing sealant
- Moss and dirt in joints with no sealant left
- Sealant pulling away from one side of the joint
If you live in an older home near Church of St Mary, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Questions to ask before booking
- Is VAT in the price?
- Whether they seal over old material or remove it
- What happens if the job turns out different
- Whether the sealant suits the joint
Towns and villages near Stone
Other services in Stone
Keeping the joints in good condition
Simple care keeps the joints in good condition. Our advice:
- Have failed joints looked at early
- Never let anyone fill a movement joint with mortar
- Keep high-pressure jets off the joints
- Do not let climbing plants root in the sealant
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years so early resealing is worth it.