East Sussex · England
External & façade joints in St Leonards, East Sussex
External mastic in St Leonards from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Leaking joints around cladding and façade panels
- Gaps where render, brick and frames meet
- Rain getting behind render or cladding at a joint
External mastic for homes and businesses in St Leonards
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Some surfaces need a primer before sealing, and we do not skip that step. Common call-outs are for movement joints with cracked, split or missing sealant and old sealant gone brittle and cracked, across copings & trims, render & cladding joints and brickwork movement joints.
In a town like St Leonards, older houses with traditional gutters sit alongside newer estates with uPVC rooflines and rendered walls. Gutter joints, fascia trims and the movement joints in newer brickwork all need sealant that can flex.
Your job is guaranteed for a year, as with all our work.
- Location
- St Leonards (TN38, TN37, TN34)
- Wider area
- East Sussex
- Cover
- A year, on every job
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Outside joints around St Leonards
St Leonards is within about 1 mile of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Rented homes near St Leonards Warrior Square station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies. For site and facilities teams at buildings such as St Leonard's Church of England Primary Academy, its movement joints, gutters and trims need looking after like any other building’s.
St Leonards is about 1 mile south-west of Hastings, in East Sussex. St Leonards gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Across East Sussex, we cover 289 places, and St Leonards is one of them. There’s also a page for Brighton, about 30 miles away.
Postcode districts we cover here for external mastic: TN38, TN37 and TN34. That includes homes and businesses on Sea Road, Fern Road and Dane Road and the roads around them. With the A259 and A2102 close by, St Leonards is simple for us to get to. Other places close to St Leonards include Silverhill (1 mile north), Hastings (1 mile north-east), America Ground (1 mile east), Bulverhythe (1 mile west) and Hollington (1 mile north). We also work in nearby towns such as Eastbourne (13 miles south-west), Bexhill-on-Sea (4 miles west), Hailsham (13 miles west), Polegate (13 miles west), Old Town (14 miles south-west) and Heathfield (15 miles north-west). St Leonards is among the bigger towns we cover in East Sussex.
Local landmarks in St Leonards
In St Leonards, that means homes and buildings near University School, Horse And Groom Public House and Summerfields Wood and the streets around them. There’s a railway station in St Leonards itself: St Leonards Warrior Square station. A little further out are Priory Meadow Shopping Centre (1.2 miles east) and Conquest Hospital (2.2 miles north). Not far away are Church Wood and Robsack Wood and Senlac Hill.
Common problems we fix in St Leonards
Sometimes a movement joint was filled with mortar or a rigid filler by mistake. The joint cannot move, so the wall cracks somewhere else instead.
Look out for any of the following:
- Sealant that has lost its bond to the brick or render
- Failed seals between different materials
- Weathered mastic that no longer stretches
- Damp patches traced to an open external joint
If you live in an older home near St John the Evangelist's Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Questions to ask before you book
- What preparation is included
- Whether they seal over old material or remove it
- How the colour is chosen
- What the cure time is
FAQs for St Leonards
Is St Leonards in your area for external mastic?
Yes, St Leonards is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or drop us an email and tell us what needs doing.
Do you work for landlords with property near St Leonards Warrior Square station?
Yes. We work for landlords and letting agents as well as homeowners, and several properties can be quoted together. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Is there a guarantee?
Yes, for a year. If there’s a problem with our work in that time, tell us and we’ll put it right.
Where is Mr Mastic based?
Mr Mastic is based in Crawley. Our applicators cover St Leonards, along with the rest of our area.
Can I add another job to the visit?
Yes. Just list everything you need.
What do you need from me for a quote?
A short description and the location, with photos by email if possible. If we need more, we’ll ask.
Can a movement joint be filled with mortar?
No, not if it’s a movement joint. Pointing it stops it working. We’ll reseal it with a flexible sealant.
Is it OK to seal over old sealant?
No, and we never do. It may look fine at first, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
Places near St Leonards
Also in St Leonards
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions.
Honest limits
Some problems need a builder, plumber or other trade rather than us:
- Movement that’s more than a sealant joint can take
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracked brickwork or render that needs a builder or plasterer
Not sure which it is? You can ring 0345 464 0079 or email us and we will tell you honestly.
Where we work in St Leonards
- Brickwork movement joints
- Render & cladding joints
- Copings & trims
- Façade panels
- Joints between brick and frames
- Concrete & block
Work for landlords, hotels and businesses
We work for landlords and letting agents as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.
The process
When we arrive, we start by going over the job with you, so you know exactly what we are doing. Surfaces next to the work are protected before work begins. Most jobs take a few hours to a few days, depending on the length of joint and the access. In St Leonards, parking is rarely complicated, though it helps to know about driveways or restrictions, and mention if the work is upstairs, in a flat or high on the outside.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Preparing for the visit
- Tell us about any previous sealing or DIY attempts
- Mention any sign-in or site rules at work premises
- Clear items away from the joints we’re working on
How to get a quote
Need a quote? Please phone 0345 464 0079 or email us and tell us about the job. We’ll explain what we’d do and give you a clear quote before work begins.
Advice
What affects the cost of external mastic
The price is agreed before any work begins. It’s based on:
- Any mould that needs treating
- The product the joint needs
- Whether old sealant or filler has to be cut out
- How much there is to do
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all play a part, and we’ll explain the quote if you ask.
What we need to know
When you contact us, these details help:
- Whether it has been sealed before
- How many joints, rooms or windows are involved
- Where the job is, and your postcode
- How we’d reach the joints
Every job is quoted individually. Just phone 0345 464 0079 or email us with the details, and photos are welcome.
Aftercare tips
Aftercare is simple:
- Keep movement joints as flexible joints, not mortar
- Wash walls gently around the sealant
- Do not let climbing plants root in the sealant
- Look over the joints every year, ideally after winter
Do not let soil, plants or ivy build up against the new joints. Anything that holds water against the joint wears it out sooner.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.