West Sussex · England
Merston External Mastic
Professional external mastic in and around Merston, with old sealant always removed completely.
- Cracked joints where brick meets render or frames
- Damp patches traced to an open external joint
- Hard, crazed mastic that has stopped moving
About our external mastic in Merston
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 joints where the bead has come unstuck and moss and dirt in joints with no sealant left, we can put it right, whatever the surface.
Older homes in small places like Merston may be stone, brick or timber-framed, often with later extensions. The joints where those materials meet are the weak points.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Place
- Merston (PO20)
- Region
- West Sussex
- Guarantee
- One year on every job
- Quote
- A clear price before we start
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What the job involves on each surface
Joints between dissimilar materials
Different materials may need different primers. We prepare both faces so the sealant bonds properly.
Concrete and blockwork
The face of concrete or block is often dusty, so cleaning and priming matter. A primer goes on where the product requires one before the bead.
Leave it or put it right?
Done well, a resealed joint is a neat, straight line that suits the wall. A rushed bead with no backing looks untidy and doesn’t last. Older cottages and farmhouses around Merston can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Homes and businesses are quoted the same way: the amount of work, how we reach it and what it needs. Call for a quick quote and we will explain what it covers.
Why book with us
- We are fully insured
- Domestic, commercial and hotel work
- Trusted Arbo and Everbuild sealants
- A choice of colours where the product allows
Read what affects the cost and what customers say.
External mastic in Merston: local notes
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. Historic houses like Goodwood House (about 3.5 miles north) are a reminder that the area around Merston has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
If you live in an older home near Church of St Giles, the joints between older walls, newer extensions and the roofline need a sealant that can move. If you let a flat or house near Chichester station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Merston is about 3 miles south-east of Chichester, in West Sussex. For external mastic in and around Merston, it’s easy to get a quote: please call 0345 464 0079 or email us. We cover West Sussex from our Crawley base. Our West Sussex coverage runs to 371 places, Merston among them. There’s also a page for Portsmouth, roughly 15 miles from Merston.
Every address in PO20 is covered for external mastic. Nearby, we also carry out external mastic in Runcton (1 mile south-west), Colworth (1 mile east), Oving (1 mile north), North Mundham (1 mile west) and Lagness (1 mile south). Larger places within reach include Worthing (15 miles east), Bognor Regis (3 miles south-east), Chichester (3 miles north-west), Selsey (6 miles south), Littlehampton (9 miles east) and Emsworth (9 miles west).
Around Merston
In Merston, that means homes and buildings near Chichester High School For Girls. For rail, the closest station is Chichester station, about 2.3 miles west. Other landmarks nearby include The Chichester City Museum (2.3 miles north-west) and St Richard's Hospital (2.3 miles north-west).
FAQs for Merston
Do you cover Merston for external mastic?
Yes. Our work covers London and the South East, and Merston is part of that. You can call 0345 464 0079 or drop us an email and let us know what needs doing.
Can you help a landlord with a rental near Chichester station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear price.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status and we are fully insured too.
Will you leave a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
What is backing rod for?
Closed-cell backing rod sets the depth of the sealant and stops it sticking to the back of the joint. That way it bonds to the two sides only and can stretch.
Can a movement joint be filled with mortar?
No. Rigid materials cannot move with the wall. If it has already been filled, we can usually cut it out and reseal it.
Can you reach joints on upper floors?
It depends on the building. Tell us the height, the number of joints and what’s below them and we will confirm how they can be reached safely.
Does someone need to be in?
We need access to the joints, so we’ll agree that with you when we book. Indoors, that usually means someone at home.
Places near Merston
What else we do in Merston
Honest limits
It helps to know what we can’t do:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Loose or hollow render, which needs re-rendering
- Cracking across the wall rather than at a joint
If you’re not sure, just call 0345 464 0079 or email us and we will give you a straight answer before you book.
Surfaces we seal
- Joints between brick and frames
- Façade panels
- Copings & trims
- Render & cladding joints
- Concrete & block
- Brickwork movement joints
What happens on the day
We keep the work tidy and contained to the joints we are treating, so you can get on with your day. The job usually takes a few hours to a few days, depending on the length of joint and the access, and we explain the cure time before we leave. For a village or hamlet like Merston, the journey is planned in advance: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- First we look over the joints with you, agree which to renew and talk through access.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Preparing for the visit
- Let us know about stairs, lifts or work at height
- Mention any leaks or damp you’ve noticed
- For business premises, tell us about site rules or sign-in
Get a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and add pictures by email if you can.
Advice
When to call us in Merston
Every building moves. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
Common reasons people contact us are:
- Brick movement joints where the sealant has split
- Leaking joints around cladding and façade panels
- Moss and dirt in joints with no sealant left
- Sealant pulling away from one side of the joint
Schools such as North Mundham Primary School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing.
Questions to ask before you book
- How hidden problems are handled
- Whether they seal over old material or remove it
- Whether you can choose the colour
- What guarantee comes with the work
DIY sealant or a professional job?
If you’ve already had a go yourself, that is fine. We cut it out and start again, so tell us about it when you ask for a quote.
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Landlord and commercial work in Merston
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.