Surrey · England
Sand mastic for sash & case windows in Hersham, Surrey
Sand mastic for Hersham and the surrounding area: careful preparation, the right product and tidy work. Call for a quick quote.
- Draughty sash windows at the surround
- Weathered mastic on the most exposed windows
- A silicone bead on a sash window that spoils the look
About our sand mastic in Hersham
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 have failed mastic on an exposed elevation and window mastic to renew ahead of painting, we can put it right.
Homes around Hersham range from older properties to newer houses, and their windows range just as widely. The right sealant depends on the frame and on what it sits in.
All our work is covered by our 12-month guarantee.
- Location
- Hersham (KT12)
- Wider area
- Surrey
- Guarantee
- 12 months on all our work
- Price
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Hersham homes and the weather
With historic houses such as The Homewood (about 1.4 miles south-east) nearby, there’s older building stock in the area around Hersham as well as newer homes. 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. 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.
Letting a property close to Walton-On-Thames station? Then any sash windows need sound mastic to keep draughts and rain out. Managing a site like Bell Farm Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages. Homes close to Church of St Peter include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Hersham is about 1 mile south of Walton-on-Thames, in Surrey. Hersham gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. 395 places in Surrey are on our list. You can also see our page for London, roughly 16 miles from Hersham.
Our applicators cover all of the KT12 postcode area for sand mastic and the streets around it. Sand mastic is available to properties on Police Station Road, Queensway South and Queensway and the roads around them. Main roads around Hersham include the A244. Neighbouring places we cover for sand mastic include Burwood Park (1 mile south-west), Walton-on-Thames (1 mile north), Whiteley Village (2 miles south-west), St George's Hill (2 miles west) and Weybridge (2 miles west). Further out, we also cover Guildford (11 miles south-west), Woking (8 miles south-west), Camberley (14 miles west), Epsom (6 miles east), Redhill (14 miles south-east) and Ewell (6 miles east).
What’s near Hersham
Typical jobs here are in homes near The Barley Mow Public House, West End Common and Three Rivers Academy. Hersham’s nearest station is Walton-On-Thames station, about 0.6 miles north-west of the centre. Well-known places in the area include No. 2 New Zealand General Hospital (1.6 miles north-west) and Chessington Castle Hill (4.8 miles east). Open spaces near Hersham include Claremont Lake and Jubilee Wood.
Honest limits
We won’t take on work that won’t last, so here’s what sealant can’t put right:
- Broken panes
- Rotten sashes, sills or window boxes (a joiner’s job)
- Sash cords, weights and draught-proofing of the sashes
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think before booking.
Surfaces we seal
- Sash and case windows
- Timber door frames
- Tenement windows
- Stone surrounds
- Brick reveals
- Period & listed homes
DIY versus a professional finish
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it lifts and traps water and mould underneath. Everything old must be removed first.
FAQs for Hersham
Is Hersham in your area for sand mastic?
Yes. We work across London and the South East, and Hersham is part of that. You can call 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear price.
Can you help a landlord with a rental near Walton-On-Thames station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just ring 0345 464 0079 or send us an email with the address and what needs doing, and we will send you a clear quote.
What does sand mastic cost?
Every job is different, so each one gets its own quote. To get one, call 0345 464 0079 or drop us an email and tell us what needs doing and where.
Can I do it myself?
It depends on the job. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional.
Does someone need to be in?
It depends on the job. For work indoors, someone needs to let us in.
Is it OK to seal over old sealant?
No. New silicone won’t bond to old silicone, and it traps any mould or water underneath. It all has to come out first.
Do you do commercial work?
Yes. Commercial and hotel work is a large part of what we do. Working times can be discussed when we quote.
Are you fully insured?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
How we quote for sand mastic
There’s no set price list. The quote depends on:
- How much old sealant there is and how hard it is to remove
- Working hours on commercial sites
- Any mould that needs treating
- The type of sealant required
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all make a difference.
What we need to know
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Where the property is
- What the problem is, such as mould, gaps, leaks or cracking
- Pictures of the joints, sent by email
- Any access issues, like height or stairs
Need a quote? Please call 0345 464 0079 or email us with a few details. We’ll explain what we’d do and give you a clear quote before we start.
What happens if it’s left?
Not every draught comes from the sashes themselves. Open mastic joints round the box can let air in, and renewing the mastic closes them. In a smaller place like Hersham, wherever a wall is exposed, a failed outside joint is a real source of damp. Inside, a split seal lets water into floors and panels just as it would anywhere.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed. Call for a quick quote and we’ll explain what it covers.
What you get with us
- More than 20 years in sealant work
- Fully insured
- Quality sealants from Arbo and Everbuild
- Approved under the ARBOMaster scheme
See what affects the cost and our reviews.
How to look after the new joints
Joint life depends on how it’s used and looked after. We suggest:
- Keep sills and gutters clear so water drains away
- Ask a joiner to look at soft timber first
- Inspect the joints round the windows every year or so
- Keep modern sealant off the mastic
Look at the mastic when you look over the windows. Small cracks are easier to deal with early.
Fine cracks show the mastic is starting to fail. It’s easier to renew it before it drops out.
How the job changes by surface
Sash and case windows
Most of our sand mastic work is on sash windows. Each joint round the box is raked out and renewed.
Tenement and terrace windows
Tenements and terraces often have many sash windows with ageing mastic. We can do one window or several.
How the visit works
There isn’t much for you to do on the day. Point us to the joints and we’ll get on with it. The job generally takes a few hours for a single window, longer for several from start to finish. For a job in Hersham, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Preparing for the visit
- Let us know if you’ve seen damp or leaks
- Let us know about stairs, lifts or work at height
- Mention if the joints have been sealed before
Ask for a quote
Getting a quote is simple: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job, and we’ll come back to you with a quote.