West Sussex · England
Sand Mastic in Thorney Island
Our applicators work in Thorney Island on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly.
- Modern sealant on a period surround
- Old sand mastic that has cracked, crumbled or fallen out
- Gaps round a timber door in stone or brick
Honest limits
We’ll always be straight with you, so here’s what new sealant won’t do:
- Putty and glazing repairs
- Decisions on consent for listed homes
- Timber that has rotted
If in doubt, call 0345 464 0079 or send us an email and we’ll say what we think before you book.
Surfaces we seal
- Sash and case windows
- Stone surrounds
- Period & listed homes
- Tenement windows
- Brick reveals
- Timber door frames
Sand mastic in Thorney Island, done properly
Burnt sand mastic is a traditional material that sits naturally against stone and brick. It suits period and listed homes where a modern sealant bead would stand out. We work on period & listed homes, tenement windows and timber door frames, and the jobs we see most are mastic round period door frames that has failed and tired mastic found when preparing windows for paint.
In a village or hamlet like Thorney Island, older cottages and farmhouses often have timber windows set in stone or brick. Not every older frame suits a modern silicone bead, so the sealant has to be chosen to suit the building.
A 12-month guarantee comes with the work, just as it does everywhere we cover.
- Place
- Thorney Island (PO10)
- Region
- West Sussex
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Thorney Island: your questions answered
Can you help a landlord with a rental near Southbourne station?
Yes, we work for landlords and agents. Just phone 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear quote.
Is Thorney Island within the area you cover?
Yes, Thorney Island is covered. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Can new sealant go over the old?
No. We remove every bit of old sealant first.
Can sand mastic be painted?
The usual advice is to leave sand mastic unpainted. If you’re redecorating the window, ask us first and we will talk you through it.
Which is right for my windows, sand mastic or modern sealant?
We will help you decide. Sand mastic suits many period homes, and modern sealants suit newer frames.
Will the old sealant be removed?
Yes, every time. New sealant will not bond properly to old, so any old material comes out before anything new goes in.
Do you offer different sealant colours?
In most cases you can choose. We’ll tell you which colours the right product comes in and agree one before any work starts.
Can old silicone round a sash window be swapped for sand mastic?
Yes, we do this often. All the old silicone is removed first so the mastic can sit properly.
Landlords, agents and businesses in Thorney Island
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can be quoted together.
Quotes for sand mastic in Thorney Island
Every job gets its own quote. This is what makes a difference:
- How much there is to do
- Mould in or behind the old joints
- The product the joint needs
- Any working-time requirements on site
Combining jobs into one visit generally makes better use of the time than several visits, so tell us about everything that needs sealing. We will give you a clear price for the lot.
What we need to know
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- What’s wrong with the joints now
- Access, such as stairs, a lift or height
- If someone has resealed it before
- Photos by email, if that’s easy
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Windows and doors in Thorney Island
Thorney Island 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 older windows and doors, 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, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Rented homes near Southbourne station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about. Schools such as Thorney Island Community Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. Homes close to The Parish Church of St Nicholas include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Thorney Island is about 4 miles south-east of Havant, in West Sussex. Anywhere in PO10, we cover sand mastic for homes and businesses. Across West Sussex, we cover 371 places, and Thorney Island is one of them. Our Portsmouth page covers work nearby, about 7 miles away.
Our applicators cover all of the PO10 postcode area for sand mastic. We cover properties on Hunter Road, Emsworth Road and Spartan Close and the roads around them. Neighbouring places we cover for sand mastic include West Thorney (1 mile south-east), North Hayling (1 mile west), Tye (1 mile south-west), Northney (1 mile west) and Emsworth (2 miles north). Further out, we also cover Bognor Regis (11 miles east), Chichester (7 miles east), Selsey (9 miles south-east), Portfield (7 miles east), Yapton (14 miles east) and East Wittering (5 miles south-east).
What’s near Thorney Island
In Thorney Island, that means homes and buildings near Bourne Community College and Eames Farm, among other places. For rail, the closest station is Southbourne station, about 1.8 miles north-east. Nearby you will also find Havant War Memorial Hospital (3.2 miles north-west) and Emsworth Museum (1.6 miles north). Open spaces near Thorney Island include Nutborne Marshes.
Leave it or put it right?
Replacing sash windows is a big decision for a period home and on a listed home, consent may be needed. Where the frames are in good order, new mastic seals the surround. Where a wall is exposed, as many are in small places like Thorney Island, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
The cost reflects the work involved, not a rough estimate. That is why we ask a few questions first.
Why book with us
- Old sealant always removed completely
- 4.9 on Google from 180+ five-star reviews
- An ARBOMaster approved applicator
- A 12-month guarantee on all work
Read our cost guide and our reviews.
What we do, step by step
There isn’t much for you to do on the day. Show us the job and we will take it from there. The job generally takes anything from a few hours to a full day, depending on how many windows. For a village or hamlet like Thorney Island, 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 look at the surrounds with you and agree the joints to renew.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- We dress the finish so it sits neatly against the masonry.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Where the joints are inside, avoid wetting them before we arrive
- Mention any tricky access
How to get a quote
Need a quote? Please call 0345 464 0079 or drop us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Related advice
Different surfaces, different methods
Period and listed homes
A traditional finish suits a period property.
Timber door frames
A neat sand mastic joint round a front door suits a period home.
Nearby places to Thorney Island
More services for Thorney Island
DIY sealant or a professional job?
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.
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly.