Kent · England
Sand Mastic in Southernden
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Southernden, with a one-year guarantee on every job. Call for a quick quote.
- Cement or filler used on old window joints that has cracked
- Wind and rain getting in round a sash window
- Gaps between timber frames and stone or brick
Sand mastic for homes and businesses in Southernden
Burnt sand mastic is a traditional material blends with stone and brick surrounds. It suits period and listed homes, where modern sealant can look out of place. We work on tenement windows, stone surrounds and period & listed homes, and the jobs we see most are weathered mastic on the most exposed windows and draughts and rain around sash boxes.
Outdoor sealant needs dry, clean surfaces, so work on frames around Southernden is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Where
- Southernden (TN27)
- Region
- Kent
- Cover
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
DIY versus a professional finish
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
Also near Southernden
More services for Southernden
Common questions in Southernden
Can you do sand mastic in Southernden?
Yes. Our work covers London and the South East, and Southernden is part of that. You can ring 0345 464 0079 or send us an email and tell us what needs doing.
Do you cover smaller places like Southernden?
Yes, Southernden is covered. Our work covers London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
Is it messy?
We keep the work tidy. Nearby surfaces are protected, and we clear up when we are done.
Should I check with the council before work on a listed or conservation-area home?
Check with your local planning authority. They decide whether consent is needed.
Can old silicone round a sash window be swapped for sand mastic?
Yes, we do this often. The old silicone has to come out completely so the mastic can sit properly.
What information do you need?
Where the job is, what the problem is and roughly how big it is. If you can, email a few photos.
Do you do commercial work?
Yes. Commercial and hotel work is a large part of what we do. Working times can be discussed when we quote.
Where do you work from?
We’re a Crawley-based firm. We work across South East England, London and Scotland.
What happens on the day
We work through the job in order: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours for a single window, longer for several. For a village or hamlet like Southernden, 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.
- Each surround is checked first.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic is not too thick.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
Getting ready for the visit
- For business premises, tell us about site rules or sign-in
- Try not to wet indoor joints just before the visit
- Keep children and pets away from the work area
Get a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints.
Related advice
Frames and glazing around Southernden
With historic houses such as Leeds Castle (about 4.8 miles north) nearby, there’s older building stock in the area around Southernden as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. 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.
Leeds Castle, about 4.8 miles north, is one of the historic houses in the wider area around Southernden. For landlords with property near Headcorn station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Southernden is about 8 miles south-east of Maidstone, in Kent. Wherever you are in the TN27 postcode area, we can carry out sand mastic at your property. We cover 922 towns and villages across Kent. You can also see our page for Crawley, roughly 37 miles from Southernden.
Every address in TN27 is covered for sand mastic. If you’re just outside Southernden, we cover Swift's Green (1 mile south), Smarden Bell (2 miles south), Headcorn (2 miles south-west), Hearnden Green (2 miles west) and Biddenden Green (2 miles south-east). Further out, we also cover Maidstone (8 miles north-west), Ashford (9 miles east), Sittingbourne (11 miles north), Faversham (13 miles north-east), Kings Hill (13 miles north-west) and Davington (13 miles north-east).
Landmarks near Southernden
The nearest railway station is Headcorn station, about 2.1 miles south-west of the centre. Nearby you will also find Coldbridge Castle (1.7 miles north-east) and Kent Firefighting Museum (3.8 miles south-west).
Aftercare tips
No joint lasts for ever, but care makes a real difference. Our tips:
- Go gently near the mastic when preparing windows
- Check the mastic when you check the paintwork
- Avoid patching sand mastic with silicone
- Renew mastic before redecorating the windows
Leave the new mastic alone while it firms up. It forms a skin fairly soon, but takes longer to harden fully.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry, so renewing it early is worth it.
For landlords and businesses
Landlords and agents in Southernden can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order before the next move-in.
From a single let to a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
What the job involves on each surface
Stone surrounds
Stone surrounds suit sand mastic well. The finish blends with the masonry.
Tenement and terrace windows
Where a building is shared, window work may involve neighbours, so check who is responsible first.
Quotes for sand mastic in Southernden
Every job gets its own quote. This is what makes a difference:
- The old material and how stubborn it is
- Working hours on commercial sites
- Whether the work is at height
- Which sealant suits the joint
Commercial jobs are quoted on the same basis as homes: how much there is to do, how we reach it and what it needs, along with when we can work on site. Ask us for a quote and we’ll explain what it covers.
Helping us quote
There’s no need for technical detail. It helps if you can tell us:
- A few pictures by email, if you can
- Whether it’s a home or a business
- The problem you’ve noticed
- Whether it has been sealed before
Every job is quoted individually, so start by telling us what you need. Just phone 0345 464 0079 or drop us an email with the details, and pictures are welcome.
Why act early in Southernden
Before painting the windows, it pays to renew the mastic. Paint over cracked mastic will not stop the gaps and traditional guidance is to leave the new mastic unpainted. Around Southernden, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
No two jobs are quite the same, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all play a part, and we will explain the quote if you ask.
Why us?
- We never seal over old sealant
- A 12-month guarantee on all work
- Domestic, commercial and hotel work
- Over 20 years’ experience