Isle of Wight · England
Dunsbury Window Mastic
Window mastic for Dunsbury, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Gaps between the frame and the inside reveal
- Water coming in at the bottom corners of a door
- Whistling draughts around closed windows
Different surfaces, different methods
Composite doors
An exposed front door gets wind-driven rain. We pay most attention there.
Aluminium frames
Metal frames expand in the sun and are often slim, with little room for error. A tidy bead in anthracite grey, black or a matching colour keeps the clean look.
How we handle window mastic in Dunsbury
A cold draught around a closed window often comes from the frame edge. A new joint stops the air getting through and quietens the whistle on windy days. Where the air is getting in through the window itself, we will say so. We work on aluminium frames, uPVC windows and patio & French doors, and common reasons people get in touch are draughty joints inside around the window and mastic that has split away from the wall.
Homes in small places like Dunsbury often stand in the open, with little to shelter their windows from wind and rain. That exposure dries out and cracks the mastic around frames and sills faster.
A 12-month guarantee comes as standard.
- Where
- Dunsbury (PO30)
- Region
- Isle of Wight
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Looking after it afterwards
Simple care keeps the joints in good condition. We recommend:
- Keep jet washers away from the mastic
- Air rooms to keep condensation down around windows
- Keep paint and stain on wooden frames in good order
- Look round the frames every year or so
Most silicone sealants will not take paint, so mention any painting plans before work begins. We can use a paintable sealant where that matters.
Water trapped behind a failed joint can start rot in timber frames and sills. Rotten timber needs a joiner, not a sealant, so early resealing is worth it.
What affects the cost of window mastic
The quote reflects the job in front of us. We look at:
- The old material and how stubborn it is
- How many rooms, windows or areas are involved
- Mould in or behind the old joints
- Which sealant suits the joint
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
Helping us quote
There’s no need for technical detail. It helps if you can tell us:
- Whether it has been sealed before
- How many joints, rooms or windows are involved
- Whether it’s a home or a business
- Photos by email, if that is easy
We quote each job on its own, so the first step is telling us about yours. Simply phone 0345 464 0079 or send us an email and describe the job, and pictures are welcome.
How the visit works
On the day, there’s very little for you to do. Point us to the joints and we will get on with it. The work itself takes a few hours for a few frames, or a day or more for a whole house. For a village or hamlet like Dunsbury, 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.
- We check how each frame can be reached safely.
- Old, cracked mastic is removed completely, along with any loose debris.
- The surfaces are cleaned and left dry, and primed where the sealant calls for it.
- Deep voids are backed, then the sealant is gunned in.
- The joint is shaped to shed water and the area tidied.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Tell us if parking is tricky
- On commercial sites, let us know about site rules
How to get a quote
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.
Advice
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
Windows and doors in Dunsbury
Dunsbury is within about 1 mile 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 the mastic around window and door frames, which can dry out and crack sooner where a building faces the weather. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Around Dunsbury, as everywhere, window mastic is only as good as the preparation behind it.
Dunsbury is about 7 miles south-west of Newport, in the Isle of Wight. Anywhere in PO30, our applicators can take on window mastic. Our area takes in 125 places across the Isle of Wight, from the larger towns to small villages. We also work in Southampton, around 18 miles away.
Every address in PO30 is covered for window mastic. Other places close to Dunsbury include Brook (1 mile south), Hulverstone (1 mile south-east), Brookgreen (1 mile south-east), Shalcombe (1 mile north-east) and Chilton Green (2 miles south-east). We also work in nearby towns such as Newport (7 miles north-east), Ryde (14 miles east), Cowes (9 miles north-east), Sandown (13 miles east), Shanklin (12 miles east) and Ventnor (12 miles east). Remote and island addresses need a little more planning, so tell us where you are when you ask for a quote.
Near you in Dunsbury
Other landmarks nearby include Yarmouth Castle (3.9 miles north-west) and Calbourne Water Mill And Rural Museum (2.3 miles north-east). Not far away are Westover Down.
Honest limits
We will not take on work that will not last, so these are the limits:
- Broken hinges, locks or handles
- Draughts through the window seals rather than the frame
- Rotten timber, which needs a joiner first
If you are not sure, just call 0345 464 0079 or send us an email and we’ll give you a straight answer.
Surfaces we seal
- Composite doors
- Patio & French doors
- Aluminium frames
- Window sills
- Timber windows & doors
- uPVC windows
Common problems we fix in Dunsbury
Timber windows bring their own problems. Old mastic gets painted over and cracks under the paint, and the wood moves with damp as well as heat.
It’s worth asking for a quote if you see:
- Mastic that is falling out in pieces
- Draughts coming in around windows and doors
- Rain getting in at the frame or under the sill
- Cracked internal joints between frame and plaster
For an older house near a landmark such as St. Mary's Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
What to look for in a quote
- Which sealant they’ll use, and why
- How much experience the applicator has
- Whether you can choose the colour
- Whether they seal over old material or remove it
Dunsbury questions
Does living near the coast affect window mastic in Dunsbury?
Coastal homes put outside sealant through more weather than inland ones, so the choice of sealant and the preparation matter even more. Walls facing the sea are generally the first to need attention.
Do you cover smaller places like Dunsbury?
Yes. Dunsbury is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
How do I get a quote for window mastic in Dunsbury?
There’s no set price, as it depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
Can you do several jobs on one visit?
Yes. Tell us about everything you’d like done and you’ll get one quote.
Is it OK to seal over old sealant?
No. Fresh sealant does not stick to old sealant, and it traps any mould or water underneath. We remove it all first.
What do you put in the joint?
Each joint gets the product that suits it. Where it moves, gets wet or faces the weather makes a difference.
Should I try DIY first?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Where do you work from?
Our base is in Crawley, and we cover South East England, London and all of Scotland.