Isle of Wight · England
Cowes External Mastic
Our applicators work in Cowes on sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and every job guaranteed for a year.
- Failed seals between different materials
- Joints pointed up with cement by mistake
- Plants rooting in failed movement joints
DIY sealant or a professional job?
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
How we handle external mastic in Cowes
For buildings in Cowes, we reseal external joints of all kinds, from brick movement joints to cladding panels. Every joint gets the same careful preparation: clean, sound faces and a controlled depth. If you are dealing with failed sealant between panels on a façade and old sealant gone brittle and cracked, we can help, on render & cladding joints, façade panels and concrete & block alike.
Extensions are a common sight on houses around Cowes, and the line where an extension meets the original house is a common leak point. Getting the joint depth right matters as much as the sealant itself.
You get a one-year guarantee, the same in Cowes as everywhere else we work.
- Location
- Cowes (PO31)
- Region
- Isle of Wight
- Cover
- One year on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What the job involves on each surface
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. The old joint is removed and a sealant that bonds to both sides goes in.
Cladding and façade panels
Panels heat up and cool down quickly, so the joints work hard every day. We choose the product to suit.
Keeping the joints in good condition
Once the sealant has cured, a few habits help it last:
- Ask before painting over external sealant
- Act on the first splits you see
- Keep movement joints as flexible joints, not mortar
- Keep high-pressure jets off the joints
Avoid pressure-washing straight into the joints. A strong jet can damage the edges of the bead.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage.
Landlord and commercial work in Cowes
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements.
Mouldy or split sealant often shows up at the end of a tenancy. Several properties can be quoted together.
Walls and rooflines in Cowes
Cowes is within about 2 miles of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. 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.
Managing a site like Cowes Primary School? Then its movement joints, gutters and trims need looking after like any other building’s. For an older house near a landmark such as St. Faith's Church, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Cowes is about 8 miles south-west of Gosport, in the Isle of Wight. From the centre of Cowes to the outskirts, external mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Across the Isle of Wight, we cover 125 places, and Cowes is one of them. Our Portsmouth page covers work nearby.
All of PO31 is within our area for external mastic, from the main roads to the quietest streets. We cover properties on Church Road, Market Hill and High Street. Main roads around Cowes include the A3020 and B3320. Neighbouring places we cover for external mastic include Gurnard (1 mile west), Northwood (1 mile south), Rew Street (1 mile south-west), Noke Common (3 miles south) and Parkhurst (3 miles south). Further out, we also cover Newport (4 miles south), Ryde (7 miles east), Sandown (10 miles south-east), Shanklin (10 miles south-east), Ventnor (12 miles south) and Oakfield (7 miles east). Cowes is one of the larger places we cover in the Isle of Wight. Remote and island addresses need a little more planning, so tell us where you are when you ask for a quote.
Near you in Cowes
In Cowes, that means homes and buildings near The Painters Arms, Isle of Wight Studio School and Cowes Enterprise College. Well-known places in the area include Isle of Wight Natural History Centre (0.5 miles south-west) and West Cowes Castle (0.7 miles north). Green spaces nearby include Briddlesford Nature Reserve and Mill Hill.
FAQs for Cowes
What guarantee comes with external mastic in Cowes?
Every job comes with our 12-month guarantee, wherever it is. We are also fully insured and ARBOMaster approved.
Does the coastal weather in Cowes affect outside sealant?
Near the sea, outside joints face more wind, rain and salt than they would inland, so preparation and the right sealant matter all the more. Walls facing the sea are normally the first to need attention.
How long does the job take?
As a guide, most jobs take anything from a few hours to several days, depending on the building. Larger jobs naturally take longer, and we’ll tell you how long to expect.
When will the joints need doing again?
It varies from wall to wall: sunny, exposed elevations and busy joints wear faster. A yearly look will tell you when they need doing. Our work comes with a one-year guarantee.
Is it worth trying it myself?
It depends on the job. High-level, external movement and fire-rated joints are professional jobs.
Why do you put foam in the joint first?
We fit closed-cell backing rod wherever the joint depth needs controlling. It sets the sealant depth and prevents three-sided bonding.
What colours does the sealant come in?
The aim is a neat, even joint in a colour that suits the wall. We will talk through colour options before any work starts, matched as closely as the range allows.
Can I add another job to the visit?
Yes, we can. More than one area can be quoted together.
Leave it or put it right?
The longer a joint stays open, the more water the wall takes in. In cold weather, frost can damage wet brick and render, so the problem grows beyond the joint itself. In Cowes, as anywhere, most leaks start as a small gap in a joint, and early is when they’re cheapest and quickest to sort.
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.
Why book with us
- Sealant colour chosen to suit
- We leave the area clean and tidy
- We never seal over old sealant
- 4.9 on Google from 180+ five-star reviews
Take a look at our cost guide or what customers say.
Nearby places to Cowes
More services for Cowes
What happens on the day
On the day, there’s very little for you to do. Point us to the joints and we’ll get on with it. The job generally takes a few hours to a few days, depending on the length of joint and the access. For a job in Cowes, we need access to where the work is and somewhere nearby to park. If the job is outside, mention gates, side access and anything above ground floor.
- 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.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Tell us about any water getting in
- Move anything stored near the joints
- Plan for the work area to be out of bounds to pets and children
Ask for a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will explain what’s involved and give you a clear quote.
Related advice
What we cannot put right
In fairness, there are a few things sealant won’t fix:
- Walls that need new movement joints cut into them
- Cracking across the wall rather than at a joint
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
If you’re not sure, just call 0345 464 0079 or email us and we will give you a straight answer before booking.
What we seal
- Façade panels
- Copings & trims
- Render & cladding joints
- Joints between brick and frames
- Brickwork movement joints
- Concrete & block