Kent · England
Sepham Heath External Mastic
Professional external mastic in and around Sepham Heath, with every bit of old sealant taken out first and a 12-month guarantee.
- Old sealant gone brittle and cracked
- Rigid filler in a joint that should flex
- Rain getting behind render or cladding at a joint
When it isn’t the sealant
We will not take on work that will not last, so here’s what sealant can’t put right:
- Structural movement, which needs a surveyor or engineer
- Cracks in the bricks or render themselves, away from the joints
- Walls that need new movement joints cut into them
If you’re not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer before booking.
What we seal
- Joints between brick and frames
- Brickwork movement joints
- Façade panels
- Copings & trims
- Concrete & block
- Render & cladding joints
External mastic for homes and businesses in Sepham Heath
External mastic is a job where short cuts show quickly. New sealant over old, joints packed with mortar and beads with no backing all tend to fail early. We strip the joint back and start again. We’re often asked to deal with gaps where render, brick and frames meet and panel joints letting water in, on façade panels, joints between brick and frames and brickwork movement joints.
Somewhere as small as Sepham Heath, homes and farm buildings often face open ground, so walls and rooflines take the full force of wind and rain. Joints on those walls need a sealant that moves with the building and stays in place.
You’re covered for a year from the day we finish. If there’s a problem with it, please call 0345 464 0079 or send us an email.
- Location
- Sepham Heath (TN14)
- Region
- Kent
- Cover
- A year, on every job
- Quote
- A clear price before we start
- Call
- 0345 464 0079
- Updated
- 26 October 2026
What we are called out for in Sepham Heath
The wrong product in a moving joint is a classic cause. A high-modulus or general-purpose sealant can be too rigid for a busy joint, and it tears off the sides.
Look out for any of the following:
- Water getting into walls through failed joints
- Joints pointed up with cement by mistake
- Gaps where render, brick and frames meet
- Weeds or debris growing in open joints
If you let a flat or house near Knockholt station, outside joints that have cracked can let damp into a rental, so check them between lets.
Questions to ask before you book
- What insurance they hold
- Which sealant they’ll use, and why
- Whether you can choose the colour
- What happens if they find a problem under the old sealant
Places near Sepham Heath
What else we do in Sepham Heath
How it works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours for a handful of joints, longer for a whole elevation, and the area is left clean. For a village or hamlet like Sepham Heath, 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.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
How to prepare
- Let us know about earlier repairs to the joints
- Move anything stored near the joints
- Where the joints are inside, avoid wetting them before we arrive
Getting a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll explain what’s involved.
Read more
Leave it or put it right?
A failed movement joint lets water into the wall, behind render and cladding. Resealing early keeps the job to the joint itself, rather than the wall around it. Around Sepham Heath, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
What you get with us
- White, clear, grey or another colour, product permitting
- We agree the colour with you first
- We never seal over old sealant
- We leave the area clean and tidy
Read what affects the cost and what customers say.
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.
Cladding and façade panels
Where a cladding system has its own specified sealant, we follow it or an approved alternative. Send us any details you have about the façade.
What affects the cost of external mastic
You will get a clear quote before any work starts. It takes into account:
- Any working-time requirements on site
- The product the joint needs
- The amount of work
- Access and height
Doing several joints on one visit is usually more efficient than separate visits. You will get one clear quote for the whole job.
Helping us quote
Photos by email are helpful but not essential. Please mention:
- Pictures of the joints, sent by email
- What the problem is, such as mould, gaps, leaks or cracking
- Roughly how big the job is
- If it’s domestic, commercial or a hotel
It all starts with a short chat. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, ring 0345 464 0079 or email us.
External mastic in Sepham Heath: local notes
Historic houses like Lullingstone Castle (about 3.1 miles north-east) are a reminder that the area around Sepham Heath 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. 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.
Schools such as Halstead Community Primary School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing. If you live in an older home near Otford Lane Mission Church, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Sepham Heath is about 3 miles north-west of Sevenoaks, in Kent. If you need external mastic in Sepham Heath, please ring 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover Kent, Sepham Heath included. Sepham Heath is one of 922 places in Kent where we work for external mastic. Our London page covers work nearby, about 16 miles away.
Every address in TN14 is covered for external mastic, from the main roads to the quietest streets. We also cover the places around Sepham Heath: Halstead (1 mile north-west), Twitton (1 mile south-east), Badgers Mount (1 mile north), Knockholt Pound (1 mile south-west) and Shoreham (1 mile north-east). Larger places within reach include Dartford (9 miles north), Sevenoaks (3 miles south-east), Royal Tunbridge Wells (14 miles south), Gravesend (12 miles north-east), Tonbridge (10 miles south-east) and Northfleet (11 miles north-east).
What’s near Sepham Heath
In Sepham Heath, that means homes and buildings near Crown Cottages The Rose And Crown Public House and Polhill Bank and the streets around them. For rail, the closest station is Knockholt station, roughly 1.7 miles north-west of the centre. Nearby you’ll also find Lullingstone Castle (3.1 miles north-east) and Sevenoaks Hospital (3.1 miles south-east). Open spaces near Sepham Heath include Betsom's Hill and Dryhill Nature Reserve.
Keeping the joints in good condition
Simple care keeps the joints in good condition. We recommend:
- Make sure movement joints aren’t pointed over
- Tell anyone working on the walls about the movement joints
- Fix overflowing gutters above sealed joints
- Walk round the building once a year and look at the joints
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Act while the splits are small. Then it’s a straightforward cut-out and reseal before water has had years to get in.
Sepham Heath: your questions answered
Do you cover smaller places like Sepham Heath?
Yes. Sepham Heath is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you cover Sepham Heath for external mastic?
Yes, Sepham Heath is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear price.
What’s an expansion joint in brickwork?
Most straight vertical gaps in brickwork are movement joints. It gives the wall room to move.
Will you leave a mess?
We keep the work tidy. We protect what’s around the joints.
Do the sealants smell?
That depends on the sealant. Some smell for a while, some hardly at all, and any smell fades as they cure.
Do you work for landlords and businesses?
Yes. Domestic, commercial and hotel work are all part of what we do.
Can a movement joint be filled with mortar?
No. A mortar-filled joint can’t move, so the movement cracks the wall elsewhere. It needs a flexible sealant over backing rod.
Where are you based?
Our base is in Crawley, West Sussex, and we work across South East England, London and Scotland.