Kent · England
Herne External Mastic
Professional external mastic in and around Herne, with old sealant always removed completely and a 12-month guarantee.
- Water getting into walls through failed joints
- Sealant pulling away from one side of the joint
- Cracked joints where brick meets render or frames
External mastic in Herne
Joints in render and cladding are easy to overlook until a damp patch appears. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant in a colour to suit. If you are dealing with gaps where render, brick and frames meet and rigid filler in a joint that should flex, we can put it right, whatever the surface.
Outbuildings, garages and conservatories around homes in places like Herne add more joints to look after. Leaks normally start at a gutter end, a garage door frame or where an extension meets the house.
Our work is backed for twelve months.
- Place
- Herne (CT6)
- Region
- Kent
- Guarantee
- One year on every job
- Quote
- A clear price before we start
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
FAQs for Herne
Do you cover smaller places like Herne?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Does the coastal weather in Herne affect outside sealant?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
What does external mastic cost?
We do not publish prices, because the cost depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Is the work guaranteed?
Yes: twelve months. If there’s a problem with our work in that time, tell us and we will put it right.
Can you quote for more than one area?
Yes, and it often makes sense. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Will the new joint stand out?
The sealant colour is picked to suit the wall, so the joint sits quietly in the wall. Exterior sealants come in a good range of colours.
Is it messy?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
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.
Should I try it myself first?
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
Some sealant jobs are within reach of a careful DIYer, 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 affects the cost of external mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- The type of sealant required
- Access and height
- How many rooms, windows or areas are involved
- Any working-time requirements on site
Commercial jobs are quoted on the same basis as homes: how much there is to do, how we reach it and what it needs. Ask us for a quote and we will go through it with you.
Helping us quote
What to tell us when you ask for a quote:
- How many joints, rooms or windows are involved
- Any previous sealing or DIY work
- Any access issues, like height or stairs
- Where the property is
To get a quote, ring 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. We’ll give you a clear price before any work starts.
Towns and villages near Herne
What else we do in Herne
Work for landlords, hotels and businesses
We also work for property managers and facilities teams in Herne and across Kent. Several sites can go on one quote.
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. We can quote for more than one property at once.
External mastic in Herne: local notes
Herne is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That’s hard on movement joints and outside wall joints, especially on the side facing the sea. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Letting a property close to Herne Bay station? Then split movement joints are easy to miss on a rental until damp shows inside. Homes close to Church of St Martin include some older properties, and old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Herne is about 1 mile south of Herne Bay, in Kent. Whether you’re in the middle of Herne or further out, we cover external mastic for every kind of property, from flats and houses to offices and hotels. Herne is one of 922 places in Kent where we work for external mastic. For nearby work, see our Chelmsford page.
Jobs for external mastic in CT6 is quoted and booked the same way as anywhere else. External mastic is available to properties on St Martin's View, Ridley Close and Herne Street and the roads around them. Close by, we work in Hunters Forstal (1 mile north-east), Eddington (1 mile north-west), Herne Common (1 mile south-west), Bullockstone (1 mile west) and Broomfield (1 mile north-east). Further out, we also cover Canterbury (5 miles south-west), Margate (11 miles east), Ramsgate (12 miles east), Broadstairs (13 miles east), Whitstable (4 miles west) and Deal (15 miles south-east).
Near you in Herne
Typical jobs here are in homes near Curtis Wood and Herne Bay High School. The nearest railway station is Herne Bay station, about 1.2 miles north-west. Well-known places in the area include Whitstable and Tankerton Hospital (3.7 miles west) and Tankerton Castle (4.4 miles west). The countryside around Herne includes West Blean and Thornden Woods.
Surface by surface
Brickwork movement joints
Brick walls have vertical movement joints to absorb expansion. They’re resealed over backing rod with a low-modulus sealant in a colour to suit the brick.
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. Their movement joints are sealed over backing rod with a flexible sealant.
What we do, step by step
We bring everything the job needs with us, so there’s nothing for you to buy. After a quick look at the joints together, the area is protected and the work begins. Most jobs take a few hours to a few days, depending on the length of joint and the access. For a job in Herne, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Clear the area around the work
- Plan for the work area to be out of bounds to pets and children
- Tell us about any water getting in
Get a quote
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. A few pictures by email make the job easier to understand.
Related advice
What happens if it’s left?
A failed movement joint lets water into the wall. Dealing with it early keeps the repair to the joint, instead of the wall and finishes around it. In a smaller place like Herne, wherever a wall is exposed, a failed outside joint is a real source of damp. Inside, a split seal lets water into floors and panels just as it would anywhere.
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. We take all of that into account in your quote.
What you get with us
- A 12-month guarantee on all work
- Fully insured
- Trusted Arbo and Everbuild sealants
- More than 20 years in sealant work
Take a look at how sealant jobs are priced or customer reviews.
Common problems we fix in Herne
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.
Common reasons people contact us include:
- Gaps where render, brick and frames meet
- Plants rooting in failed movement joints
- Sealant that has lost its bond to the brick or render
- Leaking joints around cladding and façade panels
For site and facilities teams at buildings such as Herne Church of England Infant School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Questions to ask before booking
- What insurance they hold
- Which colour the sealant will be
- Whether they seal over old material or remove it
- When the joint can take water or movement