East Sussex · England
St Helen's Sand Mastic
Our applicators work in St Helen's on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly and a 12-month guarantee.
- Gaps where the frame meets the masonry
- Draughts and rain around sash boxes
- Mastic worn away on windows facing the weather
What we do, step by step
There’s no need to move everything out, only the area right around the joints. Everything nearby is protected, and the job takes a few hours per window, depending on the condition of the joints in most cases. A visit to St Helen's is planned like any other: the time, the access and where to park are agreed in advance. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We check the window surrounds and agree which joints need renewing.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic isn’t too thick.
- The mastic is mixed, pressed into the joint by hand and shaped.
- The mastic is finished to sit tidily against the stone or brick.
Preparing for the visit
- On commercial sites, let us know about site rules
- For indoor joints, keep the area dry beforehand if you can
- Let us know about stairs, lifts or work at height
Ask for a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.
Advice
Sand mastic in St Helen's, done properly
Sand mastic has long been used to fill the joint between timber frames and masonry. It’s made from sand and a linseed-oil-based binder and built up by hand. On period homes, it looks right where silicone wouldn’t. We work on sash and case windows, stone surrounds and brick reveals, and the jobs we see most are gaps round a timber door in stone or brick and modern sealant on a period surround.
Around St Helen's, conservatories, garden rooms and patio doors are often part of the house. Those joints need the same attention as the main windows.
The work is guaranteed for twelve months. If something isn’t right with it in that time, tell us and we will put it right.
- Where
- St Helen's (TN34, TN37)
- Wider area
- East Sussex
- Guarantee
- 12 months on all our work
- Price
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
For landlords and businesses
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. We can quote for more than one property at once.
Housing providers, facilities teams and property managers book us too in St Helen's and across East Sussex. We can quote a run of properties together.
How the job changes by surface
Period and listed homes
Period homes look their best with traditional materials.
Sash and case windows
The mastic round a sash window is on show, so a neat, even finish matters.
When it is not the sealant
We will always be straight with you, so here’s what new sealant will not do:
- Damaged stone surrounds
- Sashes that need overhauling
- Cracked or broken glass
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think.
What we seal
- Tenement windows
- Period & listed homes
- Brick reveals
- Timber door frames
- Stone surrounds
- Sash and case windows
Sand mastic in St Helen's: local notes
St Helen's is within about 2 miles 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. London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Letting a property close to Ore station? Then older sash windows in a rental need their mastic kept sound to keep the weather out. If you look after a building such as Ark Blacklands Primary Academy, larger buildings have plenty of frames, and the mastic around each one ages. In the older streets around St Peter & St Paul, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
St Helen's is about 1 mile north-east of Hastings, in East Sussex. For sand mastic in and around St Helen's, please phone 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover East Sussex, St Helen's included. Our area takes in 289 places across East Sussex. You can also see our page for Brighton, roughly 31 miles from St Helen's.
All of TN34 and TN37 is covered for sand mastic, from the main roads to the quietest streets. That includes homes and businesses on Park Avenue, Keppel Road and Down's Road. If you’re just outside St Helen's, we cover Blacklands (1 mile south), Hastings (1 mile south-west), Silverhill (1 mile south-west), Belmont (1 mile south-east) and Hollington (1 mile west). Within a short drive, we also cover Eastbourne (14 miles south-west), Bexhill-on-Sea (5 miles west), Hailsham (14 miles west), Polegate (15 miles west), Old Town (15 miles south-west) and Heathfield (15 miles north-west).
Landmarks near St Helen's
In St Helen's, that means homes and buildings near William Parker Sports College, University School and The Duke pub, among other places. For rail, the closest station is Ore station, about 0.8 miles south-east. Other landmarks nearby include Priory Meadow Shopping Centre (1.2 miles south) and Hastings Old Town Hall Museum (1.3 miles south-east). Green spaces nearby include Church Wood and Robsack Wood and Senlac Hill.
Your questions about sand mastic in St Helen's
Is St Helen's within the area you cover?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Is sand mastic in a coastal place like St Helen's any different?
Near the sea, outside joints face more wind, rain and salt than they would inland, so preparation and the right sealant matter all the more. It’s worth checking the walls that face the sea first.
Should I try DIY first?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. If it does not work out, we can redo it.
Can you match the sealant colour?
Yes. Sealants come in white, clear, grey and other colours for many products, and we agree the colour with you before any work starts.
Do you hold any approvals?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
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.
Can I paint the new mastic?
Traditional guidance is not to paint over sand mastic. If you are redecorating the window, ask us first and we will advise.
Do you work for letting agents?
Yes. Domestic, commercial and hotel work are all part of what we do, and we are fully insured.
DIY sealant or a professional job?
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Also near St Helen's
More services for St Helen's
Why it’s worth doing now in St Helen's
Silicone might seem the quicker option, but on period stone or brick it often looks out of place. Sand mastic is the traditional material and blends with the stone or brick. In an older home around St Helen's, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
Why book with us
- 4.9 on Google from 180+ five-star reviews
- We never seal over old sealant
- A 12-month guarantee on all work
- Tidy, careful work
See our cost guide or customer reviews.
Keeping the joints in good condition
Aftercare is simple, and it makes a real difference:
- Sort the mastic before the decorators arrive
- Check the mastic when you check the paintwork
- Don’t run silicone over sand mastic
- Ask a joiner to look at soft timber first
Avoid painting over the new mastic, which is the traditional advice. Ask us before any decorating around it.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.