Kent · England
Chestnut Street External Mastic
External mastic across Chestnut Street and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- Joints with sealant missing in places
- Damp patches traced to an open external joint
- Hard, crazed mastic that has stopped moving
About our external mastic in Chestnut Street
We are ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Porous or awkward surfaces are primed where the sealant needs it, and we don’t skip that step. If you’re dealing with joints pointed up with cement by mistake and sealant pulling away from one side of the joint, we can put it right.
Older homes in small places like Chestnut Street may be stone, brick or timber-framed, often with later extensions. Where one material meets another is where water normally gets in, and they need the right sealant at the right depth.
Every job comes with a 12-month guarantee.
- Place
- Chestnut Street (ME9)
- Wider area
- Kent
- Cover
- 12 months on all our work
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
How it works
On the day, there’s very little for you to do. Show us the job and we will take it from there. The work itself takes a few hours to a few days, depending on the length of joint and the access, including the tidy-up. In a small place like Chestnut Street, access is normally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- Each joint is checked and the colour of the new sealant agreed.
- 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.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Tell us about any water getting in
- Let us know about parking restrictions
- For indoor joints, keep the area dry beforehand if you can
Get a quote
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is.
Read more
Also near Chestnut Street
What else we do in Chestnut Street
Can I do it myself?
If you’ve already had a go yourself, that is fine. We cut it out and start again, so just mention it when you contact us.
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
Different surfaces, different methods
Concrete and blockwork
Big joints in concrete need careful depth control. We size the backing rod to the gap so the sealant isn’t too deep.
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. We reseal them with a low-modulus sealant over backing rod in a colour to suit the brick.
Chestnut Street: your questions answered
Is Chestnut Street within the area you cover?
Yes. Chestnut Street is within the area we cover, which takes in towns, villages and rural addresses. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can you help a landlord with a rental near Newington station?
Yes. We work for landlords and agents as well as homeowners, and several properties can be quoted together. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we’ll send you a clear quote.
How long does external mastic last?
There’s no fixed answer: joints on exposed walls or with a lot of movement age sooner. Check them each year and reseal when they split or harden. Our work comes with a 12-month guarantee.
Can new sealant go over the old?
No, it won’t last. It can look neat for a few weeks, but the new layer lifts away from the old one. The old sealant has to come out completely.
Can you reach joints on upper floors?
It depends on the height and the site. Low-level joints are straightforward; for higher ones, send details and we will confirm the access.
Will you leave a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint before applying anything new.
Will the new joint stand out?
We choose a sealant colour to suit the brick, stone or render so the joint blends in. There’s a wide choice of exterior colours.
When something else is needed
Sealant isn’t the answer to every problem, and we’d rather say so up front. It won’t solve:
- Loose or hollow render, which needs re-rendering
- Walls that need new movement joints cut into them
- Cracking across the wall rather than at a joint
Not sure which it is? You can call 0345 464 0079 or email us and we will tell you honestly before you book.
Where we work in Chestnut Street
- Brickwork movement joints
- Joints between brick and frames
- Render & cladding joints
- Copings & trims
- Façade panels
- Concrete & block
How to look after the new joints
Looking after new joints is easy:
- Check external joints each spring
- Point out the joints to other trades
- Keep movement joints as flexible joints, not mortar
- Avoid pressure-washing directly into sealant joints
Do not paint over the new sealant unless we have said the product is paintable. Many exterior sealants are not designed to be painted and spoil the finish.
Once a joint can’t move, the wall finds another way, often as cracks near the joint. Catch it early and you reduce the risk.
What happens if it’s left?
Running new sealant over the old bead rarely lasts. New sealant does not bond well to old, weathered sealant, so the old joint is cut out fully first. Where a wall is exposed, as many are in small places like Chestnut Street, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, along with when we can work on site. Ask us for a quote and we’ll go through it with you.
What you get with us
- Approved under the ARBOMaster scheme
- Sanitary silicone with an anti-fungal additive in wet areas
- Full insurance on every job
- Experience in homes, commercial sites and hotels
Read what affects the cost or customer reviews.
Do you need external mastic in Chestnut Street?
If plants are growing out of a joint, the sealant has normally failed or was never there. Roots and dirt hold water against the wall and make things worse.
If you can see any of these, it’s time to have the joints looked at:
- Leaking joints around cladding and façade panels
- Joints pointed up with cement by mistake
- Moss and dirt in joints with no sealant left
- Joints where the bead has come unstuck
Schools such as Borden Church of England Primary School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s.
What your quote should include
- What the quote includes, VAT included or not
- How the colour is chosen
- What insurance they hold
- Who turns up on the day
Chestnut Street buildings and the weather
Chestnut Street is within about 3 miles of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That’s hard on movement joints and outside wall joints, especially on the side facing the sea. 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.
Rented homes near Newington station change hands often, and split movement joints are easy to miss on a rental until damp shows inside. For an older house near a landmark such as Church of St Peter and St Paul, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Chestnut Street is about 2 miles west of Sittingbourne, in Kent. Chestnut Street gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Across Kent, we cover 922 places, Chestnut Street among them. We also work in Chelmsford, around 29 miles away.
Postcode districts we cover here for external mastic: ME9. Whether your property is on Chestnut Street, Maidstone Road and Chestnut Wood Lane or anywhere close by, we can help. Other places close to Chestnut Street include Keycol (1 mile north), Bobbing (1 mile north-east), Danaway (1 mile south-west), Oad Street (1 mile south) and Newington (1 mile north-west). We also work in nearby towns such as Maidstone (9 miles south-west), Gravesend (15 miles north-west), Whitstable (15 miles east), Faversham (9 miles east), Minster (7 miles north-east) and Kings Hill (13 miles west).
Around Chestnut Street
Around Chestnut Street, our work takes us to homes and buildings near Westlands School. For rail, the closest station is Newington station, roughly 1.2 miles north-west. Nearby you’ll also find Bayford Court (2.3 miles east) and Court Hall Museum (1.9 miles east).