East Sussex · England
Sand mastic for sash & case windows in Twelve Oaks, East Sussex
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Twelve Oaks, backed by a one-year guarantee. Call for a quick quote.
- Mastic worn away on windows facing the weather
- Gaps where the frame meets the masonry
- Old cement repairs round a window that have failed
How we handle sand mastic in Twelve Oaks
For a listed home or one in a conservation area, ask your local planning authority if consent is needed before window work. Like-for-like sand mastic is often the preferred finish. If you’re dealing with weathered mastic on the most exposed windows and cement or filler used on old window joints that has cracked, we can help.
Mastic can only go onto a dry, clean joint, so window work in Twelve Oaks is booked around the forecast. Tell us about access to every side of the house, including upper-floor windows.
We stand behind the work with a one-year guarantee.
- Where
- Twelve Oaks (TN32)
- Region
- East Sussex
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Keeping the joints in good condition
Aftercare is simple, and it makes a real difference:
- Find out about consent before window work on a listed home
- Get any rot dealt with first
- Keep sills and gutters clear so water drains away
- Take care around the mastic when scraping paint
Don’t run silicone over the new mastic. If anything cracks, get it looked at rather than patching it.
Good mastic helps keep the frame dry. Once it fails, water can sit against the timber, which can lead to rot.
Twelve Oaks homes and the weather
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Bateman's (about 2.4 miles north-west) are a reminder that the area around Twelve Oaks has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
If you let a flat or house near Robertsbridge station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Twelve Oaks is about 8 miles north of Bexhill-on-Sea, in East Sussex. If you need sand mastic in Twelve Oaks, please ring 0345 464 0079 or drop us an email for a quick quote. We are based in Crawley and cover East Sussex, Twelve Oaks included. 289 places in East Sussex are on our list, from the larger towns to small villages. For nearby work, see our Brighton page, about 25 miles away.
We work across TN32 for sand mastic and the streets around it. Neighbouring places we cover for sand mastic include Hollingrove (1 mile north-east), Brightling (1 mile north), Oxley's Green (1 mile north), Netherfield (2 miles south-east) and Penhurst (2 miles south). Within a short drive, we also cover Eastbourne (13 miles south-west), Hastings (9 miles south-east), Bexhill-on-Sea (8 miles south), Hailsham (9 miles south-west), Crowborough (12 miles north-west) and St Leonards (10 miles south-east).
What’s near Twelve Oaks
The nearest railway station is Robertsbridge station, about 3.4 miles north-east. Well-known places in the area include Old Castle (2.3 miles west). For a walk, there’s Senlac Hill.
When to call us in Twelve Oaks
Timber frames move with the seasons. The movement cracks the mastic over time.
Any of these means the joints need attention:
- Old cement repairs round a window that have failed
- Wind and rain getting in round a sash window
- Silicone on a period window that looks wrong
- Tired mastic found when preparing windows for paint
Homes close to The Parish Church of St Thomas A Becket include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Comparing quotes
- What the quote includes, VAT included or not
- Whether the sealant suits the joint
- What guarantee comes with the work
- How the joint is cleaned and prepared
Also near Twelve Oaks
Other services in Twelve Oaks
Different surfaces, different methods
Stone surrounds
Sand mastic sits naturally against stone. It finishes to look like part of the surround.
Brick reveals
Brick reveals round timber windows are often pointed with sand mastic. It gives a traditional finish.
The process
On the day, we start by going over the job with you, so there are no surprises. Surfaces next to the work are protected before any work begins. Most jobs take a few hours for a single window, longer for several. Somewhere as small as Twelve Oaks, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, we look at the surrounds with you and agree what needs doing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- We pack any deep gaps so the mastic sits at the right depth.
- The mastic is mixed, pressed into the joint by hand and shaped.
- We dress the surface so it sits neatly against the masonry.
Getting ready for the visit
- Mention any leaks or damp you’ve noticed
- On commercial sites, let us know about site rules
- Tell us about access, such as stairs, a lift or high-level joints
How to get a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and add photos by email if you can.
Related advice
Why it’s worth doing now in Twelve Oaks
Before painting the windows, it pays to renew the mastic. Painting over failed mastic does not seal it, and the new mastic is traditionally left unpainted. Older cottages and farmhouses around Twelve Oaks can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Combining jobs into one visit usually makes better use of the time than several visits. We’ll give you a clear price for the lot.
Why Twelve Oaks customers choose us
- Fully insured
- One-year guarantee on every job
- An ARBOMaster approved applicator
- Any old sealant cut out fully, not covered over
Read how sealant jobs are priced and our reviews.
What sealant work can’t fix
Sealant is not the answer to every problem, and we’ll tell you before any work starts. Sealant won’t put right:
- Masonry that needs repairing
- Planning or listed building consent (your local planning authority decides)
- Sashes that rattle, stick or won’t open
If you’re not sure, just call 0345 464 0079 or email us and we will give you a straight answer.
Surfaces we seal
- Tenement windows
- Sash and case windows
- Brick reveals
- Stone surrounds
- Period & listed homes
- Timber door frames
DIY sealant or a professional job?
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.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
Common questions in Twelve Oaks
Do you work for landlords with property near Robertsbridge station?
Yes. We work for landlords and letting agents as well as homeowners. Just phone 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear quote.
Is Twelve Oaks in your area for sand mastic?
Yes. Our work covers London and the South East, and Twelve Oaks is part of that. You can phone 0345 464 0079 or email us and tell us what needs doing.
Are you an approved applicator?
Yes. We are an ARBOMaster approved applicator, which is run for the Arbo sealant brand.
Do you guarantee sand mastic work?
Our one-year guarantee covers every job, sand mastic included.
Should I use sand mastic or silicone?
We will talk it through with you. Period homes often look best with sand mastic and newer frames suit modern sealant.
Is it possible to paint over sand mastic?
The usual advice is to leave sand mastic unpainted. If you are redecorating the window, ask us first and we will advise.
Are you insured?
Yes. We are fully insured, and we can confirm the details when we quote.
Do I need permission for sand mastic on a listed building?
Speak to your local planning authority before work starts. Like-for-like sand mastic is often the preferred finish, but they decide.