West Sussex · England
External Mastic in Portslade
Sealing brickwork movement joints, render, cladding and façade joints in Portslade, with a 12-month guarantee on every job. Ask us for a quote.
- Damp patches traced to an open external joint
- Failed sealant between panels on a façade
- Plants rooting in failed movement joints
How to look after the new joints
Simple care keeps the joints in good condition. Our advice:
- Check the sealant is paintable before painting near it
- Clear growth from the base of walls and joints
- Act on the first splits you see
- Fix overflowing gutters above sealed joints
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
Once a joint cannot move, the wall finds another way, generally as cracking in the brickwork or render nearby. Catch it early and you reduce the risk.
External mastic in Portslade
Where two different materials meet, such as brick and render or blockwork and metal, they move at different rates. A flexible exterior sealant takes up that movement. We work on brickwork movement joints, façade panels and render & cladding joints, and the jobs we see most are sealant pulling away from one side of the joint and damp patches traced to an open external joint.
Outbuildings, garages and conservatories around homes in places like Portslade add more joints to look after. Leaks generally start at a gutter end, a garage door frame or where an extension meets the house.
We stand behind the work with a one-year guarantee, so you are covered after we have gone.
- Location
- Portslade (BN41, BN3, BN42)
- Region
- West Sussex
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. 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.
A careful DIYer can reseal a simple joint, 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.
How it works
Before we leave, we go over the finished joints with you and explain the cure time. The visit itself generally takes a few hours to a few days, depending on the length of joint and the access, depending on how much there is to do. A visit to Portslade is planned like any other: the time, the access and where to park are agreed in advance. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
Getting ready for the visit
- Try not to wet indoor joints just before the visit
- Mention any leaks or damp you’ve noticed
- Keep children and pets away from the work area
Ask for a quote
Need a quote? Please phone 0345 464 0079 or send us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
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FAQs for Portslade
Can you help a landlord with a rental near Fishersgate station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear quote.
Is Portslade within the area you cover?
Yes, Portslade 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.
Can a movement joint be filled with mortar?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose and can lead to cracking. A flexible sealant is the right fill.
Are you fully insured?
Yes. We are fully insured, and we can confirm the details when we quote.
Can I do it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Can you reach joints on upper floors?
It depends on the building. Where joints can be reached safely, we will do them. Give us some details and we will confirm the access.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint.
How long should I leave it?
It depends on the product and the conditions. We tell you how long to leave it before we go.
Leave it or put it right?
A properly done movement joint is an even line in a colour that suits the wall. A rushed bead with no backing looks untidy and does not last. Homes in smaller places like Portslade can face more weather, and failed outside joints let damp into walls. Indoors, a failed seal lets water into floors and panels as it would anywhere.
Doing several joints on one visit is usually more efficient than separate visits. You’ll get one clear quote for the whole job.
Why Portslade customers choose us
- Sealant colour chosen to suit
- White, clear, grey or another colour, product permitting
- A 12-month guarantee on all work
- Full insurance on every job
See our cost guide and our reviews.
Quotes for external mastic in Portslade
We quote each job individually. These are the things that affect it:
- How many rooms, windows or areas are involved
- Mould in or behind the old joints
- How much old sealant there is and how hard it is to remove
- Access and height
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. You’ll know the price before we begin.
What to tell us for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- How many joints, rooms or windows are involved
- Photos by email, if that is easy
- Where the job is, and your postcode
- If someone has resealed it before
For external mastic in Portslade, phone 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
How the job changes by surface
Copings and trims
A failed coping joint lets water into the top of the wall. Resealing them is a small job that protects a lot.
Render joints
Render is weaker at the surface than brick, so a low-modulus sealant is kinder to the joint edges. Priming is done where the sealant calls for it.
Nearby places to Portslade
Other services in Portslade
What external mastic looks like in Portslade
Portslade is within about 1 mile of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That is 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.
If you live in an older home near St Nicolas Church, older walls, gutters and the joints where extensions meet them need a flexible sealant. Managing a site like Peter Gladwin Primary School? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. If you let a flat or house near Fishersgate station, split movement joints are easy to miss on a rental until damp shows inside.
Portslade is about 1 mile west of Brighton and Hove, in West Sussex. Wherever you are in the BN41 postcode area, we cover external mastic for homes and businesses. Across West Sussex, we cover 371 places, Portslade among them.
Here we cover the BN41, BN3 and BN42 postcode area for external mastic. We cover properties on Mill Lane, Crown Road and Drove Road and the roads around them. With the A293 close by, Portslade is simple for us to get to. Neighbouring places we cover for external mastic include Hangleton (1 mile north-east), Southwick (1 mile south-west), Kingston by Sea (1 mile west), Shoreham-by-Sea (2 miles west) and Old Shoreham (3 miles west). Within a short drive, we also cover Worthing (8 miles west), Haywards Heath (12 miles north-east), Burgess Hill (9 miles north-east), Littlehampton (14 miles west), Lancing (5 miles west) and Rustington (13 miles west).
Around Portslade
We work in homes and buildings around King's School, Benfield Hill and The Mill House. For rail, the closest station is Fishersgate station, roughly 0.7 miles south. Nearby you’ll also find British Engineerium (1.8 miles east) and Southlands Hospital (1.8 miles west). The countryside around Portslade includes Shoreham Beach and Thundersbarrow Hill.
Honest limits
To be straight with you, there are a few things sealant will not fix:
- Loose or hollow render, which needs re-rendering
- Cracked brickwork or render that needs a builder or plasterer
- Subsidence or other structural problems
If in doubt, call 0345 464 0079 or drop us an email and we will say what we think before you book.
Joints and surfaces we work on
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
- Façade panels
- Copings & trims
- Joints between brick and frames