Kent · England
Swanley External Mastic
We cover Swanley for sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly.
- Panel joints letting water in
- Movement joints filled with mortar instead of sealant
- Hard, crazed mastic that has stopped moving
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
A DIY attempt does not rule out a professional job. We cut it out and start again, so just mention it when you contact us.
External mastic in Swanley
For buildings in Swanley, we reseal external joints of all kinds, from brick movement joints to cladding panels. Every joint gets the same careful preparation: clean joint faces and the right depth. Typical jobs include cracked joints where brick meets render or frames and damp patches traced to an open external joint, on copings & trims, brickwork movement joints and joints between brick and frames.
Around Swanley, garages, outbuildings and extensions all add to the joints on the outside of a home. Leaks normally start at a gutter end, a garage door frame or where an extension meets the house.
A one-year guarantee comes as standard.
- Where
- Swanley (BR8)
- Region
- Kent
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Why act early in Swanley
A failed movement joint lets water into the wall and can run behind render or cladding. Resealing early keeps the job to the joint itself, rather than the wall around it. Homes in smaller places like Swanley can face more weather, and failed outside joints let damp into walls. Inside, a split seal lets water into floors and panels just as it would anywhere.
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
Why us?
- 20+ years of sealant experience
- Any old sealant cut out fully, not covered over
- ARBOMaster approved applicator
- Fully insured
Take a look at how sealant jobs are priced or customer reviews.
Questions from Swanley
Is Swanley within the area you cover?
Yes, Swanley is covered. We work across London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
Do you work for landlords with property near Swanley station?
Yes, we work for landlords and letting agents. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Can a movement joint be filled with mortar?
No, not if it’s a movement joint. Pointing it stops it working and can lead to cracking. A flexible sealant is the right fill.
What colours does the sealant come in?
The sealant colour is picked to suit the wall so the joint blends in. Exterior sealants come in a good range of colours.
How do you reach high-level joints?
It depends on the building. Tell us the height, the number of joints and what’s below them.
What’s an expansion joint in brickwork?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It’s sealed with a flexible sealant, not mortar.
Do the sealants smell?
Sometimes, a little. It fades as the sealant cures.
How long will you be here?
A typical job takes a few hours for a handful of joints, longer for a whole elevation, including the preparation. Your quote will say how long we expect yours to take.
What else we do in Swanley
Do you need external mastic in Swanley?
A lot of failed joints come down to preparation: dusty or wet faces, no primer where one was needed, or old sealant left in. The sealant never bonds properly.
The problems people generally mention when they call include:
- Rain getting behind render or cladding at a joint
- Plants rooting in failed movement joints
- Brick movement joints where the sealant has split
- Hard, crazed mastic that has stopped moving
Schools such as St Bartholomew's Catholic Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Comparing quotes
- Are they insured?
- What the cure time is
- What guarantee comes with the work
- Whether the sealant suits the joint
Work for landlords, hotels and businesses
Failed sealant is one of the commonest items on a check-out report, and it’s quick to put right between tenancies. We can quote for more than one property at once.
We work for landlords and agents as well as homeowners. Sealant work between tenants is a simple way to keep a property in good order.
How the job changes by surface
Render joints
Rendered walls have joints at beads, openings and changes of material. We reseal them with a flexible exterior sealant that suits the render colour.
Concrete and blockwork
Wide joints in concrete need the depth controlling carefully. Backing rod sized to the joint sets it.
What we cannot put right
We’d rather tell you now than do work that will not last, so these are the limits:
- Loose or hollow render, which needs re-rendering
- Cracking across the wall rather than at a joint
- Subsidence or other structural problems
If in doubt, phone 0345 464 0079 or send us an email and we will say what we think before you book.
Where we work in Swanley
- Joints between brick and frames
- Copings & trims
- Brickwork movement joints
- Concrete & block
- Façade panels
- Render & cladding joints
External mastic in Swanley: local notes
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Lullingstone Castle (about 2.9 miles south) are a reminder that the area around Swanley has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
For an older house near a landmark such as St Mary the Virgin, an extension built onto an older house moves differently, and the joint between them takes the strain. Rented homes near Swanley station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Swanley is about 3 miles east of Orpington, in Kent. Anywhere in BR8, we cover external mastic for homes and businesses. Our Kent coverage runs to 922 places, Swanley among them. There’s also a page for London, about 14 miles away.
Postcode districts we cover here for external mastic: BR8. We cover properties on London Road, Station Road and High Street. Being close to the A20 and B258, Swanley is simple for us to get to. If you are just outside Swanley, we cover Crockenhill (1 mile south-west), Kevington (2 miles south-west), Derry Downs (3 miles west), St Mary Cray (3 miles west) and St Paul's Cray (3 miles west). Within a short drive, we also cover Dartford (4 miles north-east), Sevenoaks (8 miles south), Gravesend (9 miles east), Tonbridge (14 miles south), Northfleet (8 miles east) and Kings Hill (13 miles south-east).
Local landmarks in Swanley
We work in homes and buildings around Orchards Academy and the streets around them. There’s a railway station in Swanley itself: Swanley station. Well-known places in the area include London Borough of Bromley Museum (3.2 miles south-west) and Queen Mary's Hospital (3.4 miles north-west). Not far away are The Warren and Summer Hill.
What happens on the day
You do not need to clear the whole room or building, just the space around the work. We protect the rest, and the job takes a few hours for a handful of joints, longer for a whole elevation for a typical job. In a smaller place like Swanley, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Clear the area around the work
- For indoor joints, keep the area dry beforehand if you can
- Tell us if parking is tricky
Get a quote
Every job is quoted individually, so start by telling us what you need. Just call 0345 464 0079 or email us with the details.