East Sussex · England
Sand mastic for sash & case windows in St Leonards, East Sussex
Sand mastic across St Leonards and nearby, with every bit of old sealant taken out first.
- Modern sealant on a period surround
- Patchy fillers round a sash window
- Weathered mastic on the most exposed windows
Sand mastic for homes and businesses in St Leonards
Traditional burnt sand mastic that sits naturally against stone and brick. It suits period and listed homes where a modern sealant bead would stand out. If you have mastic round period door frames that has failed and failed mastic on an exposed elevation, we can help.
In a town like St Leonards, the windows on the most exposed side of a house take the brunt of the rain, and that’s usually where the sealant gives up first. It’s worth looking at every frame, not just the one that leaks.
Your job is guaranteed for a year, as with all our work.
- Place
- St Leonards (TN38, TN37, TN34)
- Region
- East Sussex
- Cover
- 12 months on all our work
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Why deal with it now?
Not every draught comes from the sashes themselves. Open mastic joints round the box can let air in, and renewing the mastic closes them. Gaps in sealant and mould in the bead never get better on their own, and in a busy home in St Leonards 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, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
Why book with us
- Full insurance on every job
- One-year guarantee on every job
- 20+ years of sealant experience
- Anti-fungal silicone where joints get wet
See our cost guide and customer reviews.
St Leonards homes and the weather
St Leonards is within about 1 mile 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 older windows and doors, which can dry out and crack sooner where a building faces the weather. Compared with the north and west, the South East gets less rain, 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 Leonard's Church of England Primary Academy, the mastic around its windows and doors needs looking after like any other building’s. If you live in an older home near St John the Evangelist's Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
St Leonards is about 1 mile south-west of Hastings, in East Sussex. Whether you are in the middle of St Leonards or further out, sand mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Across East Sussex, we cover 289 places, and St Leonards is one of them. We also work in Brighton, around 30 miles away.
Every address in TN38, TN37 and TN34 is covered for sand mastic. We cover properties on Sea Road, Fern Road and Dane Road. St Leonards is on the A259 and A2102, so it’s easy for us to get to with everything needed for sand mastic. Close by, we work in Silverhill (1 mile north), Hastings (1 mile north-east), America Ground (1 mile east), Bulverhythe (1 mile west) and Hollington (1 mile north). Further out, we also cover Eastbourne (13 miles south-west), Bexhill-on-Sea (4 miles west), Hailsham (13 miles west), Polegate (13 miles west), Old Town (14 miles south-west) and Heathfield (15 miles north-west). As one of the bigger places in East Sussex, St Leonards has every kind of property, from flats to offices.
Near you in St Leonards
Around St Leonards, our work takes us to homes and buildings near University School, Horse And Groom Public House and Summerfields Wood and the streets around them. St Leonards has its own railway station: St Leonards Warrior Square station. Other landmarks nearby include Priory Meadow Shopping Centre (1.2 miles east) and Conquest Hospital (2.2 miles north). Not far away are Church Wood and Robsack Wood and Senlac Hill.
Should I try it myself first?
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so just mention it when you contact us.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
What happens on the day
On the day, there’s very little for you to do. Point us to the joints and we’ll get on with it. The job generally takes a few hours for a single window, longer for several. A visit in St Leonards needs access to the work and a place to park close by. For outside work, let us know about side access, gates and any upper-floor joints.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Before we arrive
- Let us know about stairs, lifts or work at height
- Mention any sign-in or site rules at work premises
- Keep children and pets away from the work area
How to get a quote
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or send us an email.
Read more
When something else is needed
It helps to know what we cannot do too:
- Whether work needs listed building consent
- Putty and glazing repairs
- Sash cords, weights and draught-proofing of the sashes
If in doubt, call 0345 464 0079 or send us an email and we’ll say what we think before booking.
What we seal
- Stone surrounds
- Brick reveals
- Period & listed homes
- Timber door frames
- Sash and case windows
- Tenement windows
What we are called out for in St Leonards
Paint, silicone or cement used over old mastic causes problems. They don’t move with the timber, and they usually need raking out.
Look out for any of the following:
- Mastic round period door frames that has failed
- Mastic dropping out of the joint
- Failed mastic on an exposed elevation
- Tired mastic found when preparing windows for paint
Letting a property close to St Leonards Warrior Square station? Then older sash windows in a rental need their mastic kept sound to keep the weather out.
What your quote should include
- Which sealant they’ll use, and why
- How long to leave it before use
- How the joint is cleaned and prepared
- What insurance they hold
Towns and villages near St Leonards
Also in St Leonards
Quotes for sand mastic in St Leonards
For a quick quote, just ask. The main things that affect it are:
- Any mould that needs treating
- How many areas need sealing
- Which sealant suits the joint
- Whether old sealant or filler has to be cut out
Rather than a set price list, we look at what your job involves: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
What to tell us for a quote
Before you ask for a quote, have a think about:
- The type of property
- Where the job is, and your postcode
- Access, such as stairs, a lift or height
- The problem you’ve noticed
To get a quote, ring 0345 464 0079 or drop us an email with the location and a short description of the problem. You’ll have a clear quote before work begins.
How the job changes by surface
Stone surrounds
We take care not to mark the stone when the old mastic comes out.
Period and listed homes
Many older homes were built with sand mastic round the windows. On listed buildings, check with your planning authority first.
Questions from St Leonards
Does the coastal weather in St Leonards affect outside sealant?
Near the sea, outside joints face more wind, rain and salt than they would inland, so the choice of sealant and the preparation matter even more. Walls facing the sea are usually the first to need attention.
Can you help a landlord with a rental near St Leonards Warrior Square station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear quote.
Is sand mastic better than silicone for my windows?
Sand mastic usually suits period timber windows best. Modern frames normally suit a flexible sealant.
Are you fully insured?
Yes. Mr Mastic is fully insured.
Are you ARBOMaster approved?
Yes. Mr Mastic is an ARBOMaster approved applicator and we’re fully insured too.
Will the old sealant be removed?
Yes, always, and completely. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. Once we have agreed the job, you do not need to watch us work.
What sealant do you use?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we will tell you what we’re using.