Kent · England
External Mastic in Knockholt Pound
Professional external mastic in and around Knockholt Pound, with old sealant always removed completely.
- Failed sealant between panels on a façade
- Movement joints filled with mortar instead of sealant
- Sealant pulling away from one side of the joint
Why deal with it now?
The longer a joint stays open, the more water the wall takes in. In cold weather, frost can damage wet brick and render near the open joint, so the damage spreads beyond the joint. Older cottages and farmhouses around Knockholt Pound can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why Knockholt Pound customers choose us
- 4.9 on Google from 180+ five-star reviews
- We agree the colour with you first
- Sealant colour chosen to suit
- Sanitary silicone with an anti-fungal additive in wet areas
Take a look at how sealant jobs are priced or customer reviews.
How we handle external mastic in Knockholt Pound
For buildings in Knockholt Pound, 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. If you have hard, crazed mastic that has stopped moving and cracked joints where brick meets render or frames, we can put it right.
In a village or hamlet like Knockholt Pound, older cottages and farm buildings often stand in the open, where walls and rooflines take the weather head on. Gutter joints and wall joints there need a sealant that can flex and stay put.
Every job is covered by a 12-month guarantee, wherever you are in Kent.
- Place
- Knockholt Pound (TN14)
- Wider area
- Kent
- Guarantee
- A year, on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Outside joints around Knockholt Pound
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. Historic houses like Down House (about 3.2 miles west) are a reminder that the area around Knockholt Pound 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.
Letting a property close to Knockholt station? Then split movement joints are easy to miss on a rental until damp shows inside. For an older house near a landmark such as St Katharine's Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. Managing a site like Halstead Community Primary School? Then larger buildings have long runs of movement joint that eventually need resealing.
Knockholt Pound is about 4 miles north-west of Sevenoaks, in Kent. Anywhere in TN14, we cover external mastic for homes and businesses. Across Kent, we cover 922 places, Knockholt Pound among them. You can also see our page for London, about 16 miles away.
We work across TN14 for external mastic. Local streets include Old London Road, Bond Close and Main Road, all of which we cover. If you are just outside Knockholt Pound, we cover Knockholt (1 mile south-west), Halstead (1 mile north-east), Sepham Heath (1 mile north-east), Pratt's Bottom (2 miles north) and Badgers Mount (2 miles north-east). Further out, we also cover Dartford (10 miles north-east), Sevenoaks (4 miles south-east), Royal Tunbridge Wells (14 miles south-east), Gravesend (14 miles north-east), Tonbridge (11 miles south-east) and Northfleet (13 miles north-east).
Around Knockholt Pound
Locally, jobs take us to homes and businesses close to Polhill Bank and The Three Horseshoes pub, among other places. For rail, the closest station is Knockholt station, roughly 2 miles north. A little further out are Orpington Hospital (3.4 miles north) and Lullingstone Castle (4.3 miles north-east). Open spaces near Knockholt Pound include Downe Bank and Betsom's Hill.
Also near Knockholt Pound
More services for Knockholt Pound
What happens on the day
We keep the work tidy and contained to the joints we are treating, so you can carry on as normal. Expect the work to take a few hours to a few days, depending on the length of joint and the access. For a village or hamlet like Knockholt Pound, 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.
- We start by checking each joint, agreeing the ones to redo and how we will reach them.
- Old sealant and any debris are cut and raked out.
- We clean both faces of the joint and prime them where the product calls for it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Tell us about any water getting in
- Mention any tricky access
Get a quote
There’s no standard price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, phone 0345 464 0079 or send us an email.
Related advice
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
How to look after the new joints
A little care helps the new joints last. We recommend:
- Have failed joints looked at early
- Walk round the building once a year and look at the joints
- Keep soil, plants and ivy away from the joints
- Never let anyone fill a movement joint with mortar
Look over the joints once a year, ideally after winter. Watch for splits, edges coming away or growth in the joint.
An open movement joint lets rain into the wall every time it pours. Over time it can mean damp inside, stained render or frost-damaged brick which cost more to put right than the joint.
What the job involves on each surface
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. That movement goes into the joint, so the sealant in it must stay soft and stretchy.
Copings and trims
Metal and stone copings both move with temperature, so the joints need a sealant that stays flexible.
How we quote for external mastic
For a quick quote, just ask. The main things that affect it are:
- How easy the joints are to reach
- Any working-time requirements on site
- Mould in or behind the old joints
- How many rooms, windows or areas are involved
What you pay reflects the work, not guesswork. That is why we ask about the job first.
What we need to know
When you contact us, these details help:
- Any access issues, like height or stairs
- Whether it has been sealed before
- The address or postcode of the job
- Pictures of the joints, sent by email
For external mastic in Knockholt Pound, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you will get a clear quote before we start.
Your questions about external mastic in Knockholt Pound
Will you come out to Knockholt Pound?
Yes, Knockholt Pound is covered. We work across London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Do you cover Knockholt Pound for external mastic?
Yes. Our work covers London and the South East, and Knockholt Pound is part of that. Just ring 0345 464 0079 or drop us an email with a few details of the job, and we will send you a clear quote.
How long will you be here?
That depends on the amount of work, but as a guide it takes a few hours to a few days, depending on the length of joint and the access. We will tell you when we quote.
Can landlords and businesses book you?
Yes, often. Several properties can be quoted together, and between tenancies is a good time for the work.
Where is Mr Mastic based?
We work from Crawley. We cover Knockholt Pound and the rest of Kent.
Why do you put foam in the joint first?
The foam is closed-cell backing rod. It keeps the sealant at the right depth and bonded to the sides only, which would stop it stretching.
What do you need from me for a quote?
A short description and the location. We’ll ask anything else we need to know.
Can you seal joints between two different materials?
Yes. Joints between dissimilar materials are a big part of external work. The sealant is chosen to bond to both sides.
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. We can quote for more than one property at once.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.