Hampshire · England
Sand mastic for sash & case windows in Alton, Hampshire
Professional sand mastic in and around Alton, with old sealant always removed completely and a 12-month guarantee.
- Gaps where the frame meets the masonry
- Gaps round a timber door in stone or brick
- Wind and rain getting in round a sash window
Alton questions
Do you work for landlords with property near Alton station?
Yes. We work for landlords and agents as well as householders. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we’ll send you a clear quote.
Is there a guarantee on sand mastic in Alton?
All our work, in Alton and everywhere else, comes with a 12-month guarantee. We’re also fully insured and ARBOMaster approved.
What sealant do you use?
Products from Arbo and Everbuild, among others, chosen to suit the joint. We’ll tell you what we’re using and why.
Should I try DIY first?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
Do you do commercial work?
Yes, regularly. Larger jobs can be planned room by room or area by area to suit the site.
Are you an approved applicator?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
Where is Mr Mastic based?
We work from Crawley. We cover Alton and the rest of Hampshire.
Do I need permission for sand mastic on a listed building?
Check with your local planning authority. They’ll tell you if consent is needed.
About our sand mastic in Alton
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, applied by hand. On period homes, it looks right where silicone wouldn’t. We work on stone surrounds, period & listed homes and sash and case windows, and people most often call us about open joints round the window box and mastic worn away on windows facing the weather.
In a town like Alton, older houses sit alongside newer estates, with windows of every age. In every case, the joint between frame and wall is what keeps water out.
All of our work is guaranteed for twelve months, and the guarantee is the same wherever you are.
- Location
- Alton (GU34)
- Region
- Hampshire
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Landlords, agents and businesses in Alton
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.
Failed sealant is one of the commonest items on a check-out report, and it’s quick to put right between tenancies. We can quote for more than one property at once.
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 Alton, as anywhere, most leaks start as a small gap in a joint, and they’re far easier to fix early.
The cost reflects the work involved, not guesswork. That is why we ask about the job first and agree the price before starting.
Why choose Mr Mastic in Alton
- 180+ five-star Google reviews
- Anti-fungal sanitary silicone in wet areas
- Any old sealant cut out fully, not covered over
- Experience in homes, commercial sites and hotels
Frames and glazing around Alton
Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Bentworth Hall (about 3.2 miles west) are a reminder that the area around Alton has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
For landlords with property near Alton station, any sash windows need sound mastic to keep draughts and rain out. If you look after a building such as Saint Lawrence Church of England Primary School, its window and door frames need their mastic kept sound, just like a home’s. In the older streets around Church of St Lawrence, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Alton is about 10 miles south-east of Basingstoke, in Hampshire. For sand mastic in and around Alton, please ring 0345 464 0079 or send us an email for a quick quote. We cover Hampshire from our Crawley base, Alton included. Our area takes in 683 places across Hampshire, from the larger towns to small villages. You can also see our page for Reading, roughly 21 miles from Alton.
We cover every part of the GU34 postcode area for sand mastic and the streets around it. If you need sand mastic at a property on High Street, Station Road and Goswell Square or anywhere close by, we can help. Alton sits on or near the A339 and B3004. Neighbouring places we cover for sand mastic include Chawton (1 mile south-west), Holybourne (2 miles north-east), Neatham (2 miles north-east), East Worldham (2 miles south-east) and Golden Pot (2 miles north). We also work in nearby towns such as Basingstoke (10 miles north-west), Farnborough (13 miles north-east), Fleet (10 miles north-east), Aldershot (11 miles north-east), Petersfield (10 miles south) and Yateley (14 miles north-east).
What’s near Alton
Typical jobs here are in homes near Amery Hill School, Treloar School and The 'Baker's Arms' Public House. Alton has its own railway station: Alton station. A little further out are Allen Gallery (within half a mile east) and Alton Community Hospital (0.9 miles south-west). Not far away are Holybourne Hill.
What affects the cost of sand mastic
For a quick quote, just ask. What matters most is:
- The size of the job
- Whether the work is at height
- Mould in or behind the old joints
- How many areas need sealing
A failed joint rarely gets cheaper to fix by waiting. If you’re not sure whether it needs doing, phone 0345 464 0079 or email us and we will give you an honest view and a quote.
What to tell us for a quote
Before you ask for a quote, have a think about:
- Photos by email, if that is easy
- What’s wrong with the joints now
- How we’d reach the joints
- The address or postcode of the job
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll explain how we’d tackle it. When it suits you, phone 0345 464 0079 or email us.
How it works
A visit follows a simple pattern: we check the joints, mask and protect the surrounding surfaces, carry out the job and clear up. Most jobs take anything from a few hours to a full day, depending on how many windows. In Alton, parking is rarely complicated, though it helps to know about driveways or restrictions, and mention if the work is upstairs, in a flat or high on the outside.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic isn’t too thick.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Before we arrive
- Plan for the work area to be out of bounds to pets and children
- Let us know about earlier repairs to the joints
- Tell us if parking is tricky
Getting 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
What the job involves on each surface
Timber door frames
Round a period front door, sand mastic gives the right look.
Tenement and terrace windows
In shared buildings, the windows may be part of a wider repair so it’s worth checking responsibilities.
Places near Alton
What else we do in Alton
When it isn’t the sealant
Sealant isn’t the answer to every problem, and we’d rather say so up front. It won’t solve:
- Broken panes
- Crumbling stone or brickwork round the window
- Rotten sashes, sills or window boxes (a joiner’s job)
Not sure which it is? You can phone 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Sash and case windows
- Brick reveals
- Tenement windows
- Timber door frames
- Period & listed homes
- Stone surrounds
Aftercare tips
Joint life depends on how it’s used and looked after. We suggest:
- Avoid patching sand mastic with silicone
- Make sure water runs off the sill
- Find out about consent before window work on a listed home
- Avoid heavy scraping on the mastic joint
Check the mastic when you check the paintwork. Catching cracks early keeps repairs small.
Once mastic starts to crumble, rain gets in. That water can reach the timber frame and the wall so early renewal protects both.