East Sussex · England
Sand mastic for sash & case windows in Offham, East Sussex
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homes and businesses in Offham and across East Sussex. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Weathered mastic on the most exposed windows
- Crumbling sand mastic round a window
- Draughts and rain around sash boxes
What happens if it’s left?
Silicone might seem the quicker option, but it can look wrong on a period surround. Sand mastic is the traditional material and blends with the stone or brick. In a small place like Offham, homes can be exposed to wind and rain, which finds any gap, and damp in older walls is slow to dry out.
Combining jobs into one visit usually makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. We will give you a clear price for the lot.
Why book with us
- Trusted Arbo and Everbuild sealants
- Domestic, commercial and hotel work
- We never seal over old sealant
- ARBOMaster approved applicator
Read our cost guide and our reviews.
How we handle sand mastic in Offham
Sand mastic is the traditional way to point the gap between a timber window frame and the stone or brick around it. It’s a mix of sand and a linseed-oil-based binder, applied by hand. On older homes, it suits the building far better than silicone. If you have draughty sash windows at the surround and gaps round a timber door in stone or brick, we can put it right.
Outdoor sealant needs dry, clean surfaces, so work on frames around Offham is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Place
- Offham (BN7)
- Region
- East Sussex
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Work for landlords, hotels and businesses
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.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
Common problems we fix in Offham
Over the years, sand mastic weathers. It hardens, cracks and starts to come away on the stone or timber.
The problems people usually mention when they call include:
- Cracked mastic round a front door frame
- Window mastic to renew ahead of painting
- Cement or filler used on old window joints that has cracked
- Mastic worn away on windows facing the weather
If you live in an older home near Church of St Peter, the joint between an old wall and a newer frame is usually the first place rain gets in.
Questions to ask before you book
- Whether they’re fully insured
- What preparation is included
- How long the guarantee is
- Whether they seal over old material or remove it
What the job involves on each surface
Stone surrounds
The stone is treated with care when the old mastic comes out.
Sash and case windows
Most of our sand mastic work is on sash windows. We renew the mastic round each box.
How the visit works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours per window, depending on the condition of the joints, and the area is left clean. Somewhere as small as Offham, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- Deep gaps are packed so the mastic sits at the right depth.
- The sand mastic is mixed and pressed into the joint by hand.
- We dress the finish so it sits neatly against the masonry.
Before we arrive
- Mention any leaks or damp you’ve noticed
- Tell us about access, such as stairs, a lift or high-level joints
- Tell us about any previous sealing or DIY attempts
How to get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we will explain what’s involved before giving you a price.
Advice
Should I try it myself first?
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so just mention it when you contact us.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
How we quote for sand mastic
There’s no set price list, because no two jobs are the same. What we look at:
- The size of the job
- Whether old sealant or filler has to be cut out
- Whether there’s mould to deal with
- Whether the work is at height
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Asking for a quote
There’s no need for technical detail. It helps if you can tell us:
- How we’d reach the joints
- Where the job is, and your postcode
- The problem you’ve noticed
- How many joints, rooms or windows are involved
There’s no standard price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or send us an email.
FAQs for Offham
Will you come out to Offham?
Yes, we do. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Do you work for landlords with property near Cooksbridge 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 will give you a clear price.
Are you insured?
Yes. We are fully insured.
Can new sealant go over the old?
No, because it fails. The old sealant always comes out first, so the new joint bonds to clean surfaces.
Is it possible to paint over sand mastic?
It’s traditionally left unpainted, as guidance on traditional windows advises. Talk to us before any painting near it.
Do I need permission for sand mastic on a listed building?
Checking first is sensible. Your local planning authority can say if consent is needed for work on a listed home or in a conservation area.
What is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It’s made with sand and a linseed-oil-based binder.
What sealant do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We will tell you what we’re using and why.
Offham homes and the weather
With historic houses such as Anne of Cleves House (about 1.7 miles south-east) nearby, there’s older building stock in the area around Offham as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. 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 Cooksbridge 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 Wallands Community Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Offham is about 1 mile north-west of Lewes, in East Sussex. Jobs in Offham get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. 289 places in East Sussex are on our list, from the larger towns to small villages. We also work in Brighton, about 7 miles from Offham.
We cover every part of BN7 for sand mastic. We also cover Hamsey (1 mile north-east), Lewes (1 mile south-east), South Malling (1 mile south-east), Southover (2 miles south-east) and Cliffe (2 miles south-east). Further out, we also cover Eastbourne (15 miles south-east), Seaford (10 miles south-east), Hailsham (12 miles east), Crowborough (14 miles north-east), Uckfield (7 miles north-east) and Newhaven (7 miles south).
What’s near Offham
In Offham, that means homes and buildings near Railway Land, The Blacksmiths Arms and Lewes Old Grammar School and the streets around them. Offham’s nearest station is Cooksbridge station, roughly 0.9 miles north. Nearby you’ll also find Brighton And Hove Albion Football Club Museum (3.8 miles south-west) and Lewes Castle (1.5 miles south-east). Open spaces near Offham include Malling Down and Offham Hill.