Hampshire · England
Sand Mastic in Andover
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for householders, landlords and businesses in Andover. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Gaps where the frame meets the masonry
- Patchy fillers round a sash window
- Wind and rain getting in round a sash window
Aftercare tips
Once the sealant has cured, a few habits help it last:
- Don’t run silicone over sand mastic
- Avoid heavy scraping on the mastic joint
- Make sure water runs off the sill
- Plan mastic work ahead of painting
Look at the mastic when you look over the windows. Catching cracks early keeps repairs small.
Sound mastic protects the frame. Failed mastic lets water reach the timber, which can lead to rot.
About our sand mastic in Andover
Sand mastic suits most period window surrounds. Newer frames generally get a flexible sealant instead and we will explain which is best for yours. Typical jobs include open joints round the window box and weathered mastic on the most exposed windows, across timber door frames, period & listed homes and tenement windows.
Walls in Andover that face the prevailing wind take the most weather, and that’s normally where the sealant gives up first. It’s worth looking at every frame, not just the one that leaks.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Location
- Andover (SP10, SP11)
- Wider area
- Hampshire
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What we do, step by step
Most of a good job is in the preparation, and we don’t rush it. 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 Andover, 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 the window surrounds and agree which joints need renewing.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic isn’t too thick.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- We dress the surface so it sits neatly against the masonry.
Getting ready for the visit
- Mention if the joints have been sealed before
- Tell us if parking is tricky
- Mention any tricky access
How to get a quote
Need a quote? Please ring 0345 464 0079 or email us and tell us about the job. We’ll explain what we’d do and give you a clear price before any work starts.
Advice
Nearby places to Andover
Other services in Andover
DIY versus a professional finish
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it does not work out, we can still put it right.
Landlords, agents and businesses in Andover
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.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we’ll quote.
Signs you need sand mastic in Andover
Timber swells and shrinks with the weather. That movement opens up the mastic joint little by little.
Most people get in touch when they notice something like this:
- Old cement repairs round a window that have failed
- Failed mastic on an exposed elevation
- Window mastic to renew ahead of painting
- Gaps where the frame meets the masonry
Homes close to Church of St Mary include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Questions to ask before you book
- How the joint is cleaned and prepared
- Whether you can choose the colour
- What the cure time is
- How hidden problems are handled
Different surfaces, different methods
Period and listed homes
A traditional finish suits a period property, and sand mastic is one of them.
Tenement and terrace windows
Tenements and terraces often have many sash windows with ageing mastic. We can do one window or several.
Sand mastic in Andover: local notes
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For landlords with property near Andover station, older sash windows in a rental need their mastic kept sound to keep the weather out. If you look after a building such as St John the Baptist Catholic Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
Andover is about 17 miles west of Basingstoke, in Hampshire. Homes, rented property, offices and hotels in Andover can book us for sand mastic. Every job comes with our 12-month guarantee. Our area takes in 683 places across Hampshire. You can also see our page for Southampton, roughly 21 miles from Andover.
Postcode districts we cover here for sand mastic: SP10 and SP11. Whether your property is on High Street, Goddard Square and London Road or a nearby road, we can help. Andover is on the A303 and A342, which makes it straightforward to reach with everything needed for sand mastic. Other places close to Andover include Picket Twenty (1 mile east), East Anton (1 mile north-east), Knights Enham (1 mile north), Finkley Down (2 miles north-east) and Picket Piece (2 miles east). Further out, we also cover Winchester (13 miles south-east), Romsey (15 miles south), Hyde (12 miles south-east), Tidworth (8 miles west), Weeke (12 miles south-east) and Kempshott (15 miles east). As one of the bigger places in Hampshire, Andover has homes, rented property and businesses of every kind.
Around Andover
We work in homes and buildings around The Angel Inn, Winton Community Academy and Winton Community Academy and the streets around them. The nearest railway station is Andover station, roughly 0.5 miles west. Well-known places in the area include Andover War Memorial Hospital (0.7 miles north-west) and Andover Museum (within half a mile east). Green spaces nearby include Anton Lakes and Mill Lake.
Questions from Andover
Do you cover Andover for sand mastic?
Yes. We work across London and the South East, and Andover is part of that. You can phone 0345 464 0079 or email us and tell us what needs doing.
I let a flat near Andover station. Can you help?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can call 0345 464 0079 or email us with the details for a clear quote.
Do you have insurance?
Yes, we are fully insured for domestic and commercial work.
Should I check with the council before work on a listed or conservation-area home?
Your local planning authority is the one to ask. They’ll tell you if consent is needed.
Can sand mastic be painted?
Traditional guidance is not to paint over sand mastic. If you are redecorating the window, ask us first and we’ll advise.
How long does sand mastic take to harden?
It forms a skin fairly soon, then hardens over a longer period. The weather and joint depth both affect it.
Can I add another job to the visit?
Yes, and it often makes sense. Combining jobs makes good use of the visit.
Where is Mr Mastic based?
Our base is in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
What happens if it’s left?
A silicone bead can be quicker, but on period stone or brick it often looks out of place. Sand mastic is the traditional material and blends with the stone or brick. Around Andover, failed sealant lets water into hidden places, like the floor under a bath, the back of a panel or the inside of a wall. Left alone, that means rot, damp and a bigger repair.
No two jobs are quite the same, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all make a difference, and we’ll explain the quote if you ask.
Why Andover customers choose us
- ARBOMaster approved applicator
- Every job guaranteed for a year
- More than 20 years in sealant work
- Arbo and Everbuild products
Read our cost guide and our reviews.