Isle of Wight · England
Sand mastic for sash & case windows in Dunsbury, Isle of Wight
Sand mastic across Dunsbury and nearby, with every bit of old sealant taken out first.
- Weathered mastic on the most exposed windows
- Old cement repairs round a window that have failed
- Open joints round the window box
Sand mastic in Dunsbury, done properly
Old sand mastic cracks, crumbles and falls out over time, leaving gaps round the window. Renewing it closes the gap so the surround looks right again. If you have crumbling sand mastic round a window and old cement repairs round a window that have failed, we can help.
Somewhere as small as Dunsbury, older homes often have timber frames set in stone or brickwork. Older buildings like these do not always suit modern silicone, and sometimes a traditional sand mastic is the better choice.
Your job is guaranteed for a year, as with all our work.
- Where
- Dunsbury (PO30)
- Region
- Isle of Wight
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens on the day
Good joint work is mostly preparation, so that’s where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it normally takes a few hours for a single window, longer for several. In a small place like Dunsbury, access is normally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- Each surround is checked first.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic is not too thick.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Before we arrive
- Mention any leaks or damp you’ve noticed
- Keep children and pets away from the work area
- For business premises, tell us about site rules or sign-in
Getting 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 pictures by email if you can.
Related advice
How to look after the new joints
How long the joints last depends on use and care. Here’s what we suggest:
- Take care around the mastic when scraping paint
- Don’t run silicone over sand mastic
- Sort the mastic before the decorators arrive
- Find out about consent before window work on a listed home
Leave the new mastic unpainted, as traditional guidance advises. Ask us before any decorating around it.
Fine cracks show the mastic is starting to fail. Renewing it then is simpler than waiting until it falls out.
What happens if it’s left?
An open joint round the frame lets weather in. Water can get to the frame and the masonry, so dealing with it now protects both. Around Dunsbury, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. You’ll know the price before we begin.
Why choose Mr Mastic in Dunsbury
- One-year guarantee on every job
- We never seal over old sealant
- We’re fully insured
- Neat joints and a tidy finish
See our cost guide or what customers say.
Windows and doors in Dunsbury
Dunsbury is close to 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 older windows and doors, which can dry out and crack sooner where a building faces the weather. Historic houses like Mottistone Manor (about 1.2 miles east) are a reminder that the area around Dunsbury has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
Homes close to St. Mary's Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. In and around Dunsbury, as anywhere, good sand mastic starts with a clean, dry, properly prepared joint.
Dunsbury is about 7 miles south-west of Newport, in the Isle of Wight. Every kind of property in Dunsbury is covered for sand mastic, old or new, large or small. Every job comes with our one-year guarantee. Dunsbury is one of 125 places in the Isle of Wight we cover for sand mastic. You can also see our page for Southampton, roughly 18 miles from Dunsbury.
Jobs for sand mastic in PO30 works the same way as everywhere else we cover. 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). Island and remote addresses take a little more planning, so tell us where you are when you ask for a quote.
Landmarks near Dunsbury
Nearby you’ll also find 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.
What sealant work can’t fix
Some problems need a builder, plumber or other trade rather than us:
- Whether work needs listed building consent
- Timber that has rotted
- Sash cords, weights and draught-proofing of the sashes
If you are not sure, just call 0345 464 0079 or email us and we’ll give you a straight answer.
What we seal
- Sash and case windows
- Brick reveals
- Period & listed homes
- Tenement windows
- Timber door frames
- Stone surrounds
What the job involves on each surface
Stone surrounds
Stone openings are rarely perfectly straight, so the joint varies in width. We shape it by hand to follow the stone.
Brick reveals
We rake out the old mastic and pack deep voids before the new mastic goes in.
Landlords, agents and businesses in Dunsbury
Whether it’s one flat or a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
If you manage several properties in or around Dunsbury, jobs at different addresses can be quoted together. Send us the addresses and the work at each.
Common questions in Dunsbury
Is sand mastic in a coastal place like Dunsbury any different?
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.
Will you come out to Dunsbury?
Yes, we do. Our work covers London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
What does sand mastic cost?
Size, access and the old material all affect the cost. Call for a quick quote.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done.
Where do you work from?
Mr Mastic is based in Crawley. Our applicators cover Dunsbury, along with the rest of our area.
When will the new mastic be hard?
It skins over fairly quickly but takes longer to harden fully. We’ll explain what to expect before we leave.
I’m a tenant. Can you help?
We’re happy to deal with the tenant, landlord or agent. Just make sure your landlord agrees.
Is it OK to seal over old sealant?
No, and we never do. It can look neat for a few weeks, but the new layer lifts away from the old one. The old sealant has to come out completely.
Places near Dunsbury
Other services in Dunsbury
Can I do it myself?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.