Surrey · England
Sand mastic for sash & case windows in St John's, Surrey
We cover St John's for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- Gaps where the frame meets the masonry
- Mastic round period door frames that has failed
- Weathered mastic on the most exposed windows
Sand mastic in St John's
Traditional burnt sand mastic that sits naturally against stone and brick. It’s a good fit for period properties, where modern sealant can look out of place. We are often asked to deal with wind and rain getting in round a sash window and a silicone bead on a sash window that spoils the look, on period & listed homes, stone surrounds and sash and case windows.
Houses in smaller places like St John's can stand more in the open than those in a built-up town, so exposed windows and doors face the weather head on. The mastic around frames on those walls tends to age faster.
The work is covered for a year after we finish. If anything isn’t right with it, ring 0345 464 0079 or drop us an email.
- Where
- St John's (GU21, GU22)
- Region
- Surrey
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly.
What happens on the day
There’s no need to move everything out before we come, only the area right around the joints. We protect the rest, and the work takes anything from a few hours to a full day, depending on how many windows for a typical job. In a smaller place like St John's, parking is seldom the issue; lanes, gates and long drives are worth mentioning. For outside work, side access and the height of the joints help us plan.
- Each surround is checked first.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic isn’t too thick.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
How to prepare
- Mention any leaks or damp you’ve noticed
- Tell us about access, such as stairs, a lift or high-level joints
- Where the joints are inside, avoid wetting them before we arrive
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.
Advice
Different surfaces, different methods
Stone surrounds
The stone is treated with care when the old mastic comes out.
Timber door frames
Sand mastic is used round timber door frames too. The method is the same as for windows.
St John's homes and the weather
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you look after a building such as The Winston Churchill School A Specialist Sports College, larger buildings have plenty of frames, and the mastic around each one ages. Letting a property close to Woking station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about. If you live in an older home near St John's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
St John's is about 1 mile west of Woking, in Surrey. For sand mastic in and around St John's, it’s easy to get a quote: please phone 0345 464 0079 or email us. We cover Surrey from our Crawley base, St John's included. We cover 395 towns and villages across Surrey, large and small. You can also see our page for Reading, roughly 19 miles from St John's.
Work in GU21 and GU22 is quoted and booked the same way as anywhere else. That includes homes and businesses on Pond Road, Copse Road and Raglan Road. You will find St John's on the A324, which makes it straightforward to reach. If you’re just outside St John's, we cover Goldsworth Park (1 mile north-east), Woking (1 mile east), Westfield (2 miles south-east), Horsell (2 miles north-east) and Mimbridge (2 miles north). Larger places within reach include Guildford (5 miles south), Camberley (6 miles west), Epsom (14 miles east), Farnham (11 miles south-west), Ewell (15 miles east) and Egham (8 miles north).
What’s near St John's
Typical jobs here are in homes near Hoe Valley School, The Oaktree School and Royal Oak pub and the streets around them. St John's’s nearest station is Woking station, about 1.6 miles east of the centre. A little further out are Brookwood Hospital (1 mile west) and The Peacocks (1.6 miles east). Open spaces near St John's include Brookwood Lye.
Landlords, agents and businesses in St John's
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
For anyone letting property in or around St John's, several properties can be quoted together. Send us the addresses and the work at each.
St John's: your questions answered
Do you work for landlords with property near Woking station?
Yes. We work for landlords and letting agents as well as householders. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Can you do sand mastic in St John's?
Yes, St John's is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or email us and tell us what needs doing.
Do you work for hotels and businesses?
Yes. We can plan bigger jobs in stages to suit the site.
Do you hold any approvals?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
What should I tell you?
Just the basics: where it is, what you’ve noticed and how we reach it. Then call 0345 464 0079 or send us an email.
What does sand mastic cost?
We do not publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. You will get a clear quote before we start.
Should I use sand mastic or silicone?
For period timber windows in stone or brick, sand mastic is often the better fit. On modern frames, we’d normally use a flexible sealant.
Can old silicone round a sash window be swapped for sand mastic?
Often, yes. Once the silicone is out and the joint prepared, sand mastic is applied by hand.
Nearby places to St John's
What else we do in St John's
What sealant work can’t fix
Some problems need a builder, plumber or other trade rather than us:
- Decisions on consent for listed homes
- Rotten sashes, sills or window boxes (a joiner’s job)
- Putty and glazing repairs
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we’ll tell you honestly before you book.
Surfaces we seal
- Sash and case windows
- Tenement windows
- Timber door frames
- Brick reveals
- Period & listed homes
- Stone surrounds
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Renew mastic before redecorating the windows
- Find out about consent before window work on a listed home
- Take care around the mastic when scraping paint
- Inspect the joints round the windows every year or so
Avoid sealing over the mastic with silicone. If you see a crack, ask us to take a look before trying a quick fix.
Good mastic helps keep the frame dry. Once it fails, water can sit against the timber, which can lead to rot.
Why deal with it now?
Filling over old, loose mastic doesn’t last. Raking out and preparing the joint gives it a sound base so the new work lasts. Around St John's, water from a failed joint in an older home can soak into timber and plaster, which is far harder to put right than the sealant itself.
There are no prices on our website, because the cost depends so much on the job itself. For a quick quote, please ring 0345 464 0079 or drop us an email and we will talk you through it.
Why choose Mr Mastic in St John's
- Any old sealant cut out fully, not covered over
- 20+ years of sealant experience
- Trusted Arbo and Everbuild sealants
- Full insurance on every job
Read our cost guide and what customers say.