East Sussex · England
External Mastic in Sidley
Our applicators work in Sidley on sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and a one-year guarantee.
- Old sealant gone brittle and cracked
- Sealant that has lost its bond to the brick or render
- Failed sealant between panels on a façade
External mastic for homes and businesses in Sidley
A movement joint is a deliberate break that lets a wall expand and contract. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. If you have panel joints letting water in and moss and dirt in joints with no sealant left, we can put it right, whatever the surface.
Homes around Sidley range from older cottages to newer houses, with walls and rooflines of every type. Older homes need their gutter and trim joints kept tight, newer ones their movement joints.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Where
- Sidley (TN39, TN40)
- Wider area
- East Sussex
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
How it works
Once we are on site, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. After that, the work takes a few hours for a handful of joints, longer for a whole elevation. Parking around Sidley is normally easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- We start by walking round the building and agreeing the joints and the access.
- We cut out the old mastic and rake out anything in the joint.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Tell us if parking is tricky
- Keep children and pets away from the work area
- Clear items away from the joints we are working on
Getting a quote
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. A few pictures by email make the job easier to understand.
Related advice
What affects the cost of external mastic
Jobs vary more than people expect. What affects the quote:
- The type of sealant required
- The size of the job
- Any working-time requirements on site
- Whether old sealant or filler has to be cut out
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs, plus any working-time requirements on site. Call for a quick quote and we’ll go through it with you.
Helping us quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- The type of property
- Pictures of the joints, sent by email
- Access, such as stairs, a lift or height
- What the problem is, such as mould, gaps, leaks or cracking
For external mastic in Sidley, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and we’ll agree the price before any work begins.
Your questions about external mastic in Sidley
Does the coastal weather in Sidley 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.
I let a flat near Bexhill station. Can you help?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just ring 0345 464 0079 or email us with the address and what needs doing, and we will send you a clear quote.
What do you put in the joint?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice.
Will the old sealant be removed?
Yes, always, and completely. New silicone doesn’t stick to old silicone, so the joint is cleaned back first.
How do you reach high-level joints?
It depends on the height and the site. Ground-floor joints are simple; for higher work, tell us about the building and we’ll confirm what’s needed.
Where is Mr Mastic based?
We’re based in Crawley, and we cover South East England, London and all of Scotland.
Do you work in Sidley?
Yes, we do. Sidley is part of the area we cover, and the service is the same as everywhere else.
Why is there a gap in my brick wall?
Most straight vertical gaps in brickwork are movement joints. It lets the bricks expand without cracking, and it should be sealed with a flexible sealant.
DIY versus a professional finish
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
Why act early in Sidley
An open joint keeps letting water into the wall with every downpour. In cold weather, frost can damage wet brick and render around the joint, so the problem grows beyond the joint itself. In an older home around Sidley, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
A failed joint rarely gets cheaper to fix by waiting. If you are not sure whether it needs doing, phone 0345 464 0079 or email us and we will give you an honest view and a quote.
Why book with us
- White, clear, grey or another colour, product permitting
- A 12-month guarantee on all work
- Any old sealant cut out fully, not covered over
- Rated 4.9 stars on Google
Take a look at our cost guide and what customers say.
Nearby places to Sidley
What else we do in Sidley
What we’re called out for in Sidley
Many joints fail because they were sealed too deep or with nothing behind them. If the sealant sticks to the back as well as the sides, it can’t stretch and tears as soon as the joint widens.
Signs it’s time to call us include:
- Cracked joints where brick meets render or frames
- Panel joints letting water in
- Movement joints with cracked, split or missing sealant
- Moss and dirt in joints with no sealant left
For an older house near a landmark such as Church of All Saints, an extension built onto an older house moves differently, and the joint between them takes the strain.
Before you book anyone
- What the cure time is
- Which sealant they’ll use, and why
- The length of the guarantee
- Whether all the old sealant comes out first
How the job changes by surface
Render joints
Water behind render can lead to blown patches. A sound joint keeps the render dry behind.
Cladding and façade panels
Panel systems often rely on sealant between and around the panels. Each joint gets a sealant that suits the panel and its movement.
Keeping the joints in good condition
Simple care keeps the joints in good condition. We recommend:
- Show decorators and builders where the movement joints are
- Make sure movement joints aren’t pointed over
- Keep soil, plants and ivy away from the joints
- Fix overflowing gutters above sealed joints
Only paint over the joint if we have confirmed the sealant can take paint. Many exterior sealants aren’t designed to be painted.
A joint that has stopped moving pushes the movement elsewhere, normally as cracking in the brickwork or render nearby. Resealing it early helps prevent that.
Outside joints around Sidley
Sidley is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That is hard on movement joints and outside wall joints, especially on the side facing the sea. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For site and facilities teams at buildings such as All Saints Church of England Primary School, larger buildings have long runs of movement joint that eventually need resealing. Rented homes near Bexhill station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Sidley is about 1 mile north of Bexhill-on-Sea, in East Sussex. For external mastic in and around Sidley, it’s easy to get a quote: please ring 0345 464 0079 or send us an email. We are based in Crawley and cover East Sussex, Sidley included. Sidley is one of 289 towns and villages in East Sussex where we work for external mastic. There’s also a page for Brighton, about 26 miles away.
Postcode districts we cover here for external mastic: TN39 and TN40. If you need external mastic at a property on Mayo Lane, Bank Road and North Road or a nearby road, we can help. With the A2691 close by, Sidley is easy for our applicators to reach for external mastic. If you’re just outside Sidley, we cover Bexhill-on-Sea (1 mile south), Watermill (1 mile north), Lunsford's Cross (2 miles north-west), Russell's Green (3 miles north-west) and Hooe Common (3 miles west). Within a short drive, we also cover Eastbourne (9 miles south-west), Hastings (4 miles east), Hailsham (9 miles west), St Leonards (4 miles east), Polegate (10 miles west) and Hastings Old Town (5 miles east).
Near you in Sidley
We work in homes and buildings around The New Inn, Bexhill High Academy and Egerton Park, among other places. The closest station to Sidley is Bexhill station, roughly 1.4 miles south of the centre. Nearby you will also find Bexhill Hospital (0.7 miles south) and Bexhill Costume And Social History Museum (1.2 miles south). The countryside around Sidley includes Senlac Hill and Gillham Wood.