East Sussex · England
Sand mastic for sash & case windows in Lewes, East Sussex
Problem with your window and door surrounds in Lewes? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Draughty sash windows at the surround
- Patchy fillers round a sash window
- Window mastic to renew ahead of painting
When to call us in Lewes
Timber swells and shrinks with the weather. The movement cracks the mastic little by little.
People normally contact us when they notice something like this:
- Gaps between timber frames and stone or brick
- Mastic worn away on windows facing the weather
- Tired mastic found when preparing windows for paint
- Patchy fillers round a sash window
In the older streets around Church of St John sub Castro, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Questions to ask before you book
- What insurance they hold
- Whether they seal over old material or remove it
- How the colour is chosen
- How long to leave it before use
How we handle sand mastic in Lewes
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 period homes, it looks right where silicone wouldn’t. Typical jobs include mastic that needs renewing before redecorating and cracked mastic round a front door frame, on timber door frames, period & listed homes and stone surrounds.
In a town like Lewes, the windows on the most exposed side of a house take the brunt of the rain, and that is normally where the sealant gives up first. It’s worth looking at every frame, not just the one that leaks.
Whatever the size of the job, it’s backed by our one-year guarantee in Lewes and across East Sussex.
- Where
- Lewes (BN7, BN8, BN6, RH15)
- Region
- East Sussex
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Towns and villages near Lewes
Other services in Lewes
Questions from Lewes
Is sand mastic in Lewes guaranteed?
Every job comes with our one-year guarantee, wherever it is. We’re fully insured, and an ARBOMaster approved applicator.
I let a flat near Lewes station. Can you help?
Yes, we work for landlords and letting agents. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear quote.
What sealant do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Do I need to be at home?
It depends on the job. For work indoors, someone needs to let us in, and for outside work we will agree access with you when we book.
How long does sand mastic take?
It depends on the size of the job, but as a guide it takes anything from a few hours to a full day, depending on how many windows. We will tell you when we quote.
Where do you work from?
We work from Crawley. Our applicators cover Lewes, along with the rest of our area.
When will the new mastic be hard?
The surface skins quite quickly and it hardens fully over a longer time. Timing depends on the weather and the joint.
Can sand mastic be painted?
It’s traditionally left unpainted, which is what traditional guidance recommends. Ask us before decorating.
Why deal with it now?
Not every filler suits an old window surround. Sand mastic is the like-for-like choice, which can matter on listed and conservation-area homes. In Lewes, as anywhere, most leaks start as a small gap in a joint, and they’re far easier to fix early.
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, call 0345 464 0079 or email us for an honest opinion and a quote.
Why us?
- Full insurance on every job
- Anti-fungal sanitary silicone in wet areas
- Trusted Arbo and Everbuild sealants
- Over 20 years’ experience
Read how sealant jobs are priced and customer reviews.
For landlords and businesses
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
Letting agents and landlords in Lewes can book us as well as householders. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
How to look after the new joints
So the new joints stay in good condition:
- Renew mastic before redecorating the windows
- Go gently near the mastic when preparing windows
- Check with your local planning authority if your home is listed
- Avoid patching sand mastic with silicone
Check the mastic when you check the paintwork. Catching cracks early keeps repairs small.
Good mastic helps keep the frame dry. Failed mastic lets water reach the timber and timber that stays wet can rot.
How it works
Good joint work is mostly preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes a few hours for a single window, longer for several. For a job in Lewes, we need access to where the work is and somewhere nearby to park. If the job is outside, mention gates, side access and anything above ground floor.
- 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.
Preparing for the visit
- Tell us if parking is tricky
- Mention any leaks or damp you’ve noticed
- Let us know about earlier repairs to the joints
Get a quote
Every job is quoted individually, so the first step is telling us about yours. Simply phone 0345 464 0079 or drop us an email and describe the job.
Read more
Frames and glazing around Lewes
With historic houses such as Anne of Cleves House (about 0.6 miles south) nearby, there’s older building stock in the area around Lewes as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you let a flat or house near Lewes station, any sash windows need sound mastic to keep draughts and rain out. Schools such as Lewes Old Grammar School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
Lewes is about 7 miles north-east of Brighton, in East Sussex. Homes, rented property, offices and hotels in Lewes can book us for sand mastic, old or new, large or small. The work is guaranteed for a year. 289 places in East Sussex are on our list, from the larger towns to small villages. Our Brighton page covers work nearby.
Postcode districts we cover here for sand mastic: BN7, BN8, BN6 and RH15. Sand mastic is available to properties on Market Lane, Market Street and High Street. Main roads around Lewes include the A26 and A275, which makes travel easy. Close by, we work in South Malling (1 mile north-east), Southover (1 mile south-east), Cliffe (1 mile east), Offham (1 mile north-west) and Hamsey (1 mile north). Further out, we also cover Eastbourne (14 miles south-east), Seaford (8 miles south-east), Hailsham (11 miles east), Crowborough (14 miles north-east), Uckfield (8 miles north-east) and Newhaven (6 miles south). As one of the bigger places in East Sussex, Lewes has homes, rented property and businesses of every kind.
Local landmarks in Lewes
Around Lewes, our work takes us to homes and buildings near Priory School, St Pancras Catholic Primary School and Railway Land and the streets around them. The closest station to Lewes is Lewes station, roughly 0.6 miles south-east. A little further out are Lewes Victoria Hospital (0.5 miles west) and Museum of Agricultural Bygones (3.9 miles east). For a walk, there’s Offham Hill and Malling Down.
Surface by surface
Timber door frames
A neat sand mastic joint round a front door suits a period home.
Stone surrounds
Old stone surrounds are often uneven, so the gap isn’t the same all the way round. We shape it by hand to follow the stone.
What sealant work cannot fix
We’d rather tell you now than do work that won’t last, so these are the limits:
- Planning or listed building consent (your local planning authority decides)
- Rotten sashes, sills or window boxes (a joiner’s job)
- Broken panes
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Tenement windows
- Period & listed homes
- Sash and case windows
- Timber door frames
- Brick reveals
- Stone surrounds