West Sussex · England
External Mastic in Cocking
External mastic for Cocking, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Movement joints filled with mortar instead of sealant
- Moss and dirt in joints with no sealant left
- Brick movement joints where the sealant has split
How we handle external mastic in Cocking
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 where a rigid filler would soon crack. We are often asked to deal with plants rooting in failed movement joints and damp patches traced to an open external joint, across joints between brick and frames, façade panels and render & cladding joints.
Older homes in small places like Cocking may be stone, brick or timber-framed, often with later extensions. The joints where those materials meet are the weak points, and they need the right sealant at the right depth.
Our work is backed for twelve months, in Cocking and everywhere else we cover.
- Place
- Cocking (GU29)
- Wider area
- West Sussex
- Guarantee
- A year, on every job
- Price
- A clear price before we start
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Landlords, agents and businesses in Cocking
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we will give you a quote.
Letting agents and landlords in Cocking can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
Cocking: your questions answered
Is external mastic in Cocking guaranteed?
All our work, in Cocking and everywhere else, comes with a 12-month guarantee. We’re fully insured, and an ARBOMaster approved applicator.
Do you cover Cocking for external mastic?
Yes. Our work covers London and the South East, and Cocking is part of that. Just ring 0345 464 0079 or drop us an email with a few details of the job.
Do you seal joints where cladding meets other materials?
Yes. Different materials move at different rates, so the joint between them must be flexible. We choose one that suits both surfaces.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint.
How do you reach high-level joints?
It depends on the building. We work on joints that can be reached safely. Tell us about the building and we will confirm what access is needed.
What is backing rod for?
Backing rod controls the sealant depth and keeps it off the back of the joint. That way it bonds to the two sides only and can stretch.
Is it OK to seal over old sealant?
No, and we never do. It may look fine at first, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Is there any odour?
Possibly a little. It fades as the sealant cures, and ventilation helps.
What we cannot put right
To be straight with you, some problems need a different trade:
- Structural movement, which needs a surveyor or engineer
- Cracked brickwork or render that needs a builder or plasterer
- Rising or penetrating damp from elsewhere in the wall
If in doubt, phone 0345 464 0079 or send us an email and we will say what we think before you book.
Surfaces we seal
- Concrete & block
- Render & cladding joints
- Brickwork movement joints
- Façade panels
- Copings & trims
- Joints between brick and frames
Walls and rooflines in Cocking
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Cowdray House (about 2.6 miles north) are a reminder that the area around Cocking has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
Homes close to St Catherine of Siena Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant.
Cocking is about 8 miles north of Chichester, in West Sussex. Every kind of property in Cocking is covered for external mastic. The work is guaranteed for a year. Our West Sussex coverage runs to 371 places, Cocking among them. For nearby work, see our Portsmouth page (17 miles or so).
Work in GU29 works the same way as everywhere else we cover. That includes homes and businesses on Bell Lane, The Croft and Cherry Close. We also cover the places around Cocking: Bepton (1 mile north-west), Heyshott Green (1 mile north-east), Cocking Causeway (1 mile north), Heyshott (1 mile east) and Bepton Common (2 miles north). Within a short drive, we also cover Bognor Regis (12 miles south), Chichester (8 miles south), Selsey (15 miles south), Littlehampton (14 miles south-east), Emsworth (11 miles south-west) and Rustington (14 miles south-east).
Around Cocking
Nearby you’ll also find Midhurst Community Hospital (3 miles north) and Midhurst Museum (2.5 miles north). Green spaces nearby include Levin Down and Iping and Stedham Commons.
Common problems we fix in Cocking
Sometimes a movement joint was filled with mortar or a rigid filler by mistake. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Signs it’s time to call us include:
- Brick movement joints where the sealant has split
- Failed seals between different materials
- Leaking joints around cladding and façade panels
- Movement joints filled with mortar instead of sealant
Around Cocking, as everywhere, external mastic is only as good as the preparation behind it.
What your quote should include
- How hidden problems are handled
- Is VAT in the price?
- What guarantee comes with the work
- Are they insured?
Aftercare tips
Looking after new joints is easy:
- Ask before painting over external sealant
- Wash walls gently around the sealant
- Keep water from gutters off the wall
- Never let anyone fill a movement joint with mortar
Have a quick look at the joints each spring. Watch for splits, edges coming away or growth in the joint.
If you can see gaps, plants or bare sections in a joint, have it checked. Early work is quicker and leaves a better finish.
What we do, step by step
On the day, we look over the joints with you first, so you know exactly what we are doing. We protect the surfaces around the joints before any work begins. Most jobs take anything from a few hours to several days, depending on the building. Somewhere as small as Cocking, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- The old mastic and anything lodged in the joint is removed.
- Both sides are cleaned back to sound material and primed if needed.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
How to prepare
- Mention any tricky access
- For indoor joints, keep the area dry beforehand if you can
- Clear items away from the joints we are working on
Get a quote
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. A few photos by email make the job easier to understand, and we will take it from there.
Related advice
How the job changes by surface
Brickwork movement joints
People sometimes point up a brick movement joint by mistake. Where one has been mortared, we cut it out and reseal it with sealant where it can be done safely.
Render joints
The face of render can be soft, so a low-modulus sealant is kinder to the joint edges. We prime where the product needs it.
What affects the quote in Cocking
You’ll get a clear quote before work begins. It takes into account:
- Any working-time requirements on site
- How much old sealant there is and how hard it is to remove
- Mould in or behind the old joints
- The size of the job
Doing several joints on one visit normally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. You will get one clear quote for the whole job.
Helping us quote
You do not need to know the technical terms. It helps if you can tell us:
- Pictures of the joints, sent by email
- What’s wrong with the joints now
- How we’d reach the joints
- Any previous sealing or DIY work
We do not publish a price list. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or drop us an email.