Kent · England
External Mastic in Longfield
We cover Longfield for sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and a 12-month guarantee.
- Weeds or debris growing in open joints
- Leaking joints around cladding and façade panels
- Water getting into walls through failed joints
External mastic in Longfield
Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, so once it splits or hardens, the joint stops working and water gets in. Typical jobs include movement joints with cracked, split or missing sealant and movement joints filled with mortar instead of sealant, across render & cladding joints, joints between brick and frames and copings & trims.
Somewhere as small as Longfield, homes and farm buildings often face open ground, where walls and rooflines take the weather head on. Gutter joints and wall joints there need a sealant that can flex and stay put.
Whatever the size of the job, it’s backed by our 12-month guarantee.
- Where
- Longfield (DA3)
- Wider area
- Kent
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Different surfaces, different methods
Copings and trims
Metal and stone copings both move with temperature, so a flexible sealant suits them best year round.
Cladding and façade panels
Cladding and façade panels are normally separated by sealed joints. We reseal them with a sealant suited to the panel material.
Common problems we fix in Longfield
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.
People usually contact us when they notice one of these:
- Sealant that has lost its bond to the brick or render
- Plants rooting in failed movement joints
- Rigid filler in a joint that should flex
- Rain getting behind render or cladding at a joint
For an older house near a landmark such as Church of Saint Mary Magdalene, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Comparing quotes
- How the surfaces are prepared before sealing
- Whether they’re fully insured
- Whether all the old sealant comes out first
- What happens if the job turns out different
Questions from Longfield
Can you do external mastic in Longfield?
Yes, Longfield is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or email us and tell us what needs doing, and we’ll give you a clear quote.
Do you cover smaller places like Longfield?
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.
Is it OK to seal over old sealant?
No, because it fails. The old sealant always comes out first, so the new sealant bonds properly.
Why do you put foam in the joint first?
We fit closed-cell backing rod wherever the joint depth needs controlling. It sets the sealant depth and prevents three-sided bonding.
Do you work for landlords and businesses?
Yes. We work for householders, landlords, letting agents, businesses and hotels in Longfield.
Is the work guaranteed?
Yes. There’s a 12-month guarantee on every job, large or small.
Can you seal joints between two different materials?
Yes. We cut out the old sealant, prepare both faces and reseal with a flexible exterior product. We pick a colour that works with both materials.
What is a movement joint?
Brickwork, render and cladding all move a little, and planned joints take up that movement. The gap is sealed with a flexible sealant over backing rod.
When it is not the sealant
To be straight with you, some problems need a different trade:
- Cracking across the wall rather than at a joint
- Cutting new joints into brickwork, which is building work rather than sealant work
- Rising or penetrating damp from elsewhere in the wall
If in doubt, phone 0345 464 0079 or send us an email and we’ll say what we think before you book.
What we seal
- Joints between brick and frames
- Concrete & block
- Brickwork movement joints
- Copings & trims
- Render & cladding joints
- Façade panels
Outside joints around Longfield
Historic houses like Cobham College (about 4 miles east) are a reminder that the area around Longfield has older buildings as well as new. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you look after a building such as Longfield Academy, its movement joints, gutters and trims need looking after like any other building’s. If you let a flat or house near Longfield station, split movement joints are easy to miss on a rental until damp shows inside.
Longfield is about 3 miles south-west of Northfleet, in Kent. From the centre of Longfield to the outskirts, we cover external mastic for every kind of property, from flats and houses to offices and hotels. Across Kent, we cover 922 places, and Longfield is one of them. You can also see our page for London, roughly 19 miles from Longfield.
Work in DA3 works the same way as everywhere else we cover. We cover properties on Station Road, Main Road and Ightham Close. We also cover Hartley (1 mile south), New Barn (1 mile east), Longfield Hill (1 mile south-east), New Ash Green (2 miles south) and Nash Street (2 miles east). We also work in nearby towns such as Maidstone (13 miles south-east), Dartford (5 miles north-west), Sevenoaks (10 miles south-west), Gravesend (4 miles north-east), Tonbridge (14 miles south) and Northfleet (3 miles north-east).
Landmarks near Longfield
In Longfield, that means homes and buildings near Railway Tavern, Hartley Primary Academy and Rectory Meadow, among other places. Longfield has its own railway station: Longfield station. A little further out are Darent Valley Hospital (3.3 miles north-west) and Stone Castle (3.4 miles north). The countryside around Longfield includes Sawyers Lake.
Why act early in Longfield
Pointing a movement joint with mortar might seem a neat fix, but it locks the joint solid. The wall then cracks somewhere else. A flexible sealant over backing rod is what the joint needs. In a small place like Longfield, homes can be exposed to wind and rain, which finds any gap, and older walls, once damp, take a long time to dry.
Homes and businesses are quoted the same way: the amount of work, how we reach it and what it needs, along with when we can work on site. Call for a quick quote and we’ll go through it with you.
What you get with us
- Any old sealant cut out fully, not covered over
- We leave the area clean and tidy
- Rated 4.9 stars on Google
- Colour picked to suit the job
Take a look at what affects the cost and what customers say.
DIY versus a professional finish
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What we do, step by step
On the day, we look over the joints with you first, so there are no surprises. Surfaces next to the work are protected before we start. Most jobs take a few hours to a few days, depending on the length of joint and the access. In a small place like Longfield, access is generally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- 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.
- Both sides are cleaned back to sound material and primed if needed.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Before we arrive
- Keep children and pets away from the work area
- Mention any parking rules near the property
- Tell us about any water getting in
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.
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Places near Longfield
What else we do in Longfield
Landlords, agents and businesses in Longfield
Hotels need rooms back in use, so we plan the work room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
Housing providers, facilities teams and property managers book us too. Several sites can go on one quote, and we’re fully insured.