Isle of Wight · England
Cowes Window Mastic
We cover Cowes for mastic around window and door frames, sills and patio doors. Old material cut out, joints cleaned and sealed neatly and a one-year guarantee.
- Hard, cracked sealant around windows
- Gaps between the frame and the inside reveal
- Cracked sealant at the sill ends
What we do, step by step
You do not need to clear the whole room or building before we come, only the area right around the joints. Everything nearby is protected, and the work takes anything from an hour or two to a full day, depending on how many frames there are for a typical job. Parking in a town like Cowes is normally straightforward, but tell us if there’s a driveway or any restrictions, and mention if the work is upstairs, in a flat or high on the outside.
- First we look at every frame and agree the list.
- The old mastic is cut out and the surfaces cleaned back.
- We fit backing rod in deep gaps so the sealant is the right depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Finally we tidy up and check each joint.
How to prepare
- Tell us about any water getting in
- For business premises, tell us about site rules or sign-in
- Mention any parking rules near the property
Get a quote
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we will talk you through the work and give you a clear quote.
Advice
Window mastic for homes and businesses in Cowes
Over two decades of sealing frames has taught us which products suit which walls. We’re fully insured ARBOMaster approved applicators, and we give a 12-month guarantee on the work. If you’re dealing with damp patches on the reveal after heavy rain and gaps between the frame and the inside reveal, we can help.
Walls in Cowes that face the prevailing wind take the most weather, and that is generally where the sealant gives up first. It’s worth looking at every frame, not just the one that leaks.
Every job is covered by a 12-month guarantee.
- Place
- Cowes (PO31)
- Wider area
- Isle of Wight
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Places near Cowes
More services for Cowes
DIY sealant or a professional job?
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Why act early in Cowes
Draughts and leaks don’t always mean new windows. Where the frames are sound, new mastic generally deals with draughts and leaks at the edges. Problems with the glass or gaskets are for a window company, and we will say so. Black mould and gaps in sealant don’t fix themselves, and in a busy home in Cowes they get worse with every use. Now is the easy time to put it right.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why book with us
- Arbo and Everbuild products
- White, clear, grey or coloured to suit, where the product allows
- Neat joints and a tidy finish
- Old sealant always removed completely
See our cost guide or customer reviews.
Surface by surface
Patio & French doors
The joints around patio doors run a long way, top, sides and threshold. Most leaks start at the bottom corners, so they get particular care.
uPVC windows
uPVC expands and contracts noticeably with temperature, so the joint needs a low-modulus sealant that stays flexible. We match white, brown, anthracite grey and black frames.
What window mastic looks like in Cowes
Cowes is within about 2 miles of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on the mastic around window and door frames, which can dry out and crack sooner where a building faces the weather. Historic houses like Osborne House (about 1.7 miles east) are a reminder that the area around Cowes has older buildings as well as new. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
In the older streets around St. Faith's Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Cowes is about 8 miles south-west of Gosport, in the Isle of Wight. For window mastic in and around Cowes, it’s easy to get a quote: please phone 0345 464 0079 or email us. We are based in Crawley and cover the Isle of Wight, Cowes included. Across the Isle of Wight, we cover 125 places, and Cowes is one of them. We also work in Portsmouth, about 11 miles from Cowes.
Here we cover the PO31 postcode area for window mastic. If you need window mastic at a property on Church Road, Market Hill and High Street or a nearby road, our applicators can take on the job. With the A3020 and B3320 close by, Cowes is simple for us to get to. Neighbouring places we cover for window 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). Within a short drive, 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. For island and remote addresses, the job takes a little more planning, so mention it when you ask for a quote.
Around Cowes
We work in homes and buildings around The Painters Arms, Isle of Wight Studio School and Cowes Enterprise College, among other places. Other landmarks nearby include Isle of Wight Natural History Centre (0.5 miles south-west) and West Cowes Castle (0.7 miles north). The countryside around Cowes includes Briddlesford Nature Reserve and Mill Hill.
Keeping the joints in good condition
So the new joints stay in good condition:
- Paint up to the joint, not over it
- Look round the frames every year or so
- Ventilate rooms so frames do not stay wet inside
- Avoid harsh chemicals near the mastic
Try not to touch the new joint while it cures, following the cure time we give you. Keep jet washers away from the frames.
A failed joint lets water into the wall a little at a time. You might not see it until plaster blows or a damp patch appears inside. Early resealing stops it reaching that point.
Cowes: your questions answered
Is window mastic in Cowes guaranteed?
All our work, in Cowes and everywhere else, comes with a 12-month guarantee. We’re fully insured, and an ARBOMaster approved applicator.
Do you cover Cowes for window mastic?
Yes, Cowes is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or drop us an email and tell us what needs doing.
Will it make a mess?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
Do you seal inside as well as outside?
Yes. Outside is the weather seal; inside closes the gap to the plaster. We can do either or both.
Is it OK to seal over old sealant?
No, because it fails. We remove every bit of old sealant first, so the new joint bonds to clean surfaces.
Are you insured?
Yes, we’re fully insured for every job we do.
How long before the joint can be used?
Different products cure at different speeds, so please follow the time we give you.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done and you will get one quote.
For landlords and businesses
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. We can quote for more than one property at once.
We also work for property managers and facilities teams in Cowes and across the Isle of Wight. We can quote a run of properties together, and we’re fully insured for the work.
Common problems we fix in Cowes
Some failures date back to when the windows were fitted. Sealant run over dust, wet brick or loose mortar never bonded as it should, and it lets go sooner than it should.
It’s worth asking for a quote if you see:
- Mastic that has split away from the wall
- Gaps where the sill meets the wall
- Untidy mastic left by window fitters
- Gaps between the frame and the inside reveal
Schools such as Cowes Primary School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
What to look for in a quote
- What happens if the job turns out different
- What preparation is included
- Is VAT in the price?
- Which sealant they’ll use, and why