Hampshire · England
Sand mastic for sash & case windows in St Leonards, Hampshire
Sand mastic across St Leonards and nearby, with old sealant always removed completely.
- Draughty sash windows at the surround
- Window mastic to renew ahead of painting
- Mastic worn away on windows facing the weather
Sand mastic in St Leonards, done properly
Sand mastic is the traditional way to point the gap between a timber window frame and the stone or brick around it. It’s made from sand and a linseed-oil-based binder and built up by hand. On older homes, it suits the building far better than silicone. We work on sash and case windows, tenement windows and brick reveals, and common reasons people get in touch are mastic dropping out of the joint and old cement repairs round a window that have failed.
Many houses in smaller places like St Leonards have conservatories, garden rooms or patio doors. Those joints need the same attention as the main windows.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Location
- St Leonards (BH24)
- Region
- Hampshire
- Cover
- A year, on every job
- Quote
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What the job involves on each surface
Period and listed homes
A traditional finish suits a period property, and sand mastic is one of them.
Sash and case windows
On a sash window, the mastic joint shows on the outside, so a neat, even finish matters.
Nearby places to St Leonards
What else we do in St Leonards
How the visit works
Before we leave, we go over the finished joints with you and explain the cure time. The visit itself generally takes anything from a few hours to a full day, depending on how many windows, depending on the size of the job. For a job in St Leonards, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- Each surround is checked first.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic isn’t too thick.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Preparing for the visit
- Mention any parking rules near the property
- For business premises, tell us about site rules or sign-in
- Mention if the joints have been sealed before
Ask for a quote
If you’re in St Leonards and need sand mastic, ring 0345 464 0079 or drop us an email. Tell us what the problem is and where, and we’ll agree the price before any work begins.
Related advice
Do you need sand mastic in St Leonards?
Previous repairs in cement or silicone often trap water or crack away. They do not suit the joint, and they generally need raking out.
Signs it’s time to call us include:
- Patchy fillers round a sash window
- Weathered mastic on the most exposed windows
- A silicone bead on a sash window that spoils the look
- Cracked mastic round a front door frame
Homes close to All Saints include some older properties, and the joint between an old wall and a newer frame is usually the first place rain gets in.
Before booking anyone
- How the surfaces are prepared before sealing
- Whether the sealant suits the joint
- Whether you can choose the colour
- What happens if the job turns out different
Quotes for sand mastic in St Leonards
The quote reflects the job in front of us. We take into account:
- The old material and how stubborn it is
- Which sealant suits the joint
- The number of rooms or windows
- The amount of work
Homes and businesses are quoted the same way: the amount of work, the access and the products needed. Ask us for a quote and we’ll go through it with you.
Asking for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- A few photos by email, if you can
- If someone has resealed it before
- How many joints, rooms or windows are involved
- The problem you’ve noticed
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. Whenever you’re ready, phone 0345 464 0079 or email us.
When it is not the sealant
Honest advice matters more to us than a booking, so here’s what sealant cannot fix:
- Sash cords, weights and draught-proofing of the sashes
- Planning or listed building consent (your local planning authority decides)
- Damaged stone surrounds
If in doubt, phone 0345 464 0079 or send us an email and we’ll say what we think.
Where we work in St Leonards
- Tenement windows
- Brick reveals
- Sash and case windows
- Stone surrounds
- Period & listed homes
- Timber door frames
Questions from St Leonards
Can you do sand mastic in St Leonards?
Yes, St Leonards is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or email us with a few details of the job.
What guarantee comes with sand mastic in St Leonards?
Every job comes with our one-year guarantee, wherever it is. We are fully insured, and an ARBOMaster approved applicator.
Do you have insurance?
Yes. We are fully insured.
Can you work on commercial sites?
Yes. Hotels, offices and other businesses use us, and we are fully insured.
Can you seal over the old sealant?
No. New silicone won’t bond to old silicone, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
Should I use sand mastic or silicone?
We’ll talk it through with you. Period homes often look best with sand mastic, and modern sealants suit newer frames.
Should I check with the council before work on a listed or conservation-area home?
Yes, it’s worth checking. Ask your local planning authority whether consent is needed for work on a listed home or in a conservation area.
How long does sand mastic take to go off?
It forms a skin fairly soon and it hardens fully over a longer time. The weather and joint depth both affect it.
Should I try it myself first?
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.
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. We can quote for more than one property at once.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements.
What sand mastic looks like in St Leonards
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.
For site and facilities teams at buildings such as St Ives Primary & Nursery School, larger buildings have plenty of frames, and the mastic around each one ages.
St Leonards is in Hampshire. St Leonards gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. We cover 683 towns and villages across Hampshire, from the larger towns to small villages. For nearby work, see our Southampton page, about 21 miles away.
Work in BH24 is quoted and booked the same way as anywhere else. You’ll find streets such as Cedar Avenue, Birch Close and Malmesbury Road, and we cover them all. If you’re just outside St Leonards, we cover Ashley Heath (1 mile north), St Ives (1 mile north-east), Matchams (1 mile south-east) and Avon Castle (2 miles east). We also work in nearby towns such as Lymington (14 miles east), New Milton (10 miles south-east), Ringwood (3 miles north-east), Barton on Sea (10 miles south-east), Ashley (10 miles south-east) and Milford on Sea (13 miles south-east).
What’s near St Leonards
Locally, jobs take us to homes and businesses close to Avon Heath Country Park. Nearby you’ll also find St Leonard's Hospital (0.9 miles south-west) and Stapehill Abbey (3.9 miles south-west). The countryside around St Leonards includes Linbrook Lake and Blashford Lakes.