West Sussex · England
External & façade joints in Keynor Estate, West Sussex
Our applicators work in Keynor Estate on sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and a one-year guarantee.
- Sealant that has lost its bond to the brick or render
- Plants rooting in failed movement joints
- Rigid filler in a joint that should flex
What happens on the day
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes anything from a few hours to several days, depending on the building. Somewhere like Keynor Estate needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- The old mastic and anything lodged in the joint is removed.
- 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.
Getting ready for the visit
- For indoor joints, keep the area dry beforehand if you can
- On commercial sites, let us know about site rules
- Let us know if you’ve seen damp or leaks
How to get a quote
For a quick quote, get us on the phone, or email us if that’s easier. Tell us about the joints that need doing and we’ll talk you through the work and send you a clear quote.
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External mastic in Keynor Estate, done properly
External mastic is a job where short cuts show quickly. New sealant over old, joints packed with mortar and beads with no backing rarely last long. We take the old material out and do it properly. Common call-outs are for panel joints letting water in and failed seals between different materials, on copings & trims, brickwork movement joints and concrete & block.
External sealant needs dry, clean surfaces, so work around Keynor Estate is planned for dry weather. Tell us about access to all sides of the building, including outbuildings and garages.
Each job carries a 12-month guarantee.
- Where
- Keynor Estate (PO20)
- Wider area
- West Sussex
- Cover
- A year, on every job
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Honest limits
A few problems are outside what sealant work can do:
- Damp that isn’t coming from the joint
- Movement that is more than a sealant joint can take
- Cracks in the bricks or render themselves, away from the joints
Not sure which it is? You can ring 0345 464 0079 or send us an email and we will tell you honestly before booking.
What we seal
- Render & cladding joints
- Concrete & block
- Joints between brick and frames
- Façade panels
- Brickwork movement joints
- Copings & trims
Also near Keynor Estate
Other services in Keynor Estate
Keynor Estate: your questions answered
Do you work for landlords with property near Chichester station?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Does living near the coast affect external mastic in Keynor Estate?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. The right product, a clean joint and the right depth all help it cope.
Is it OK to fill a movement joint with cement?
No. Mortar locks the joint solid, so the wall cracks somewhere else instead. It needs a flexible sealant over backing rod.
Do you use backing rod?
We fit closed-cell backing rod wherever the joint depth needs controlling. It sets the sealant depth and prevents three-sided bonding so the bead can stretch.
Are you insured?
Yes, we are fully insured for every job we do.
How long does external mastic take?
Most jobs take a few hours for a handful of joints, longer for a whole elevation, including preparation and clearing up. We will confirm how long when we quote.
What should I tell you?
The location, the problem and the rough size of the job. If you can, email a few photos.
What’s an expansion joint in brickwork?
A vertical gap in a long brick wall is generally a movement joint. It gives the wall room to move, and it should be sealed with a flexible sealant.
Walls and rooflines in Keynor Estate
Keynor Estate is close to 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. 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.
For an older house near a landmark such as St Mary Our Lady Sidlesham, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Letting a property close to Chichester station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Keynor Estate is about 2 miles north of Selsey, in West Sussex. Wherever you are in the PO20 postcode area, we can carry out external mastic at your property. We cover 371 towns and villages across West Sussex. Our Portsmouth page covers work nearby (13 miles or so).
Jobs for external mastic in PO20 works the same way as everywhere else we cover. If you need external mastic at a property on Chalk Lane and Cow Lane or anywhere close by, our applicators can take on the job. Other places close to Keynor Estate include Sidlesham (1 mile north-east), Street End (1 mile north), Church Norton (2 miles south-east), Sidlesham Common (2 miles north) and Pagham (2 miles east). Within a short drive, we also cover Bognor Regis (5 miles east), Chichester (5 miles north), Littlehampton (12 miles east), Emsworth (8 miles north-west), Rustington (13 miles east) and Angmering (14 miles east).
Landmarks near Keynor Estate
Around Keynor Estate, our work takes us to homes and buildings near The Academy, among other places. The closest station to Keynor Estate is Chichester station, about 4.4 miles north of the centre. Nearby you will also find Selsey Lifeboat Museum (2.9 miles south) and St Richard's Hospital (5.2 miles north).
Landlord and commercial work in Keynor Estate
We work for landlords and agents as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Why deal with it now?
Resealing a run of joints in one go is usually better than patching one at a time. Joints of the same age tend to fail together. Older cottages and farmhouses around Keynor Estate can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
What it costs depends on the amount of work, how hard the old material is to remove and access to the work. We give a clear quote before work begins, so you know where you stand.
Why book with us
- A choice of colours where the product allows
- Any old sealant cut out fully, not covered over
- Domestic, commercial and hotel work
- 180+ five-star Google reviews
Read what affects the cost and customer reviews.
Do you need external mastic in Keynor Estate?
Weeds, moss and debris in a joint are a sign the sealant has gone. Dirt and roots then trap moisture in the joint.
Common reasons people contact us include:
- Weathered mastic that no longer stretches
- Joints with sealant missing in places
- Water getting into walls through failed joints
- Sealant pulling away from one side of the joint
Schools such as Sidlesham Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
What your quote should include
- How long to leave it before use
- The length of the guarantee
- How the colour is chosen
- What happens if the job turns out different
How to look after the new joints
Aftercare is simple:
- Make sure movement joints are not pointed over
- Wash walls gently around the sealant
- Have failed joints looked at early
- Ask before painting over external sealant
Only paint over the joint if we’ve confirmed the sealant can take paint. Paint can crack on a flexible joint and spoil the finish.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
Quotes for external mastic in Keynor Estate
Jobs vary more than people expect. The main factors:
- Access and height
- The amount of work
- The number of rooms or windows
- Any mould that needs treating
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you are unsure, ring 0345 464 0079 or drop us an email for an honest opinion and a quote.
Asking for a quote
Before you ask for a quote, have a think about:
- How many joints, rooms or windows are involved
- A few photos by email, if you can
- Where the property is
- What’s wrong with the joints now
Want a quote for external mastic? Please phone 0345 464 0079 or email us with a few details. We’ll explain what we’d do and give you a clear price before any work starts.