Kent · England
Sand mastic for sash & case windows in Bonnington, Kent
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homeowners, landlords and businesses in Bonnington. Fully insured, ARBOMaster approved and guaranteed for a year.
- Mastic dropping out of the joint
- Draughty sash windows at the surround
- Weathered mastic on the most exposed windows
Sand mastic in Bonnington
Sand mastic skins over fairly quickly but full hardening takes longer. Traditional guidance is not to paint over it, so ask us before you decorate. If you have crumbling sand mastic round a window and tired mastic found when preparing windows for paint, we can help, whatever the surface.
Somewhere as small as Bonnington, older homes often have timber frames set in stone or brickwork. Not every older frame suits a modern silicone bead, so the sealant has to be chosen to suit the building.
The work is guaranteed for twelve months. If something isn’t right with it in that time, tell us and we’ll put it right.
- Where
- Bonnington (TN25)
- Wider area
- Kent
- Cover
- A year, on every job
- Quote
- A clear price before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What the job involves on each surface
Brick reveals
Gaps between frame and brick let in rain and draughts. Renewing the mastic closes it.
Sash and case windows
Sash windows are where we do most sand mastic work. We renew the mastic round each box.
Also near Bonnington
More services for Bonnington
Leave it or put it right?
Filling over old, loose mastic doesn’t last. Raking out and preparing the joint gives it a sound base so the new work lasts. Older cottages and farmhouses around Bonnington can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
Doing several joints on one visit normally makes better use of the time than several visits. We’ll give you a clear quote for the lot.
Why choose Mr Mastic in Bonnington
- Experience in homes, commercial sites and hotels
- More than 20 years in sealant work
- Approved under the ARBOMaster scheme
- Fully insured
Read how sealant jobs are priced and our reviews.
Work for landlords, hotels and businesses
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can be quoted together.
Landlords and letting agents in Bonnington can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order before the next move-in.
Bonnington questions
Do you work for landlords with property near Ham Street station?
Yes, rental work is part of what we do. You can call 0345 464 0079 or send us an email with the address and a few details, and we will give you a fixed price before we start.
Do you cover smaller places like Bonnington?
Yes. Bonnington is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
What’s sand mastic made of?
Sand mastic is a traditional material for pointing round windows and doors. It combines sand with a linseed-oil-based binder.
Do you have insurance?
Yes. We are fully insured.
Do I have to be there?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
What guarantee comes with the work?
Every job comes with our 12-month guarantee.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
When will the new mastic be hard?
The surface skins quite quickly and it hardens fully over a longer time. Timing depends on the weather and the joint.
What affects the cost of sand mastic
The quote reflects the job in front of us. We look at:
- Working hours on commercial sites
- The product the joint needs
- The old material and how stubborn it is
- Whether the work is at height
The cost depends on how much there is to do, how hard the old material is to remove and access to the work. We give a clear quote before any work starts, so you know where you stand.
What we need to know
There’s no need for technical detail. It helps if you can tell us:
- A few photos by email, if you can
- What the problem is, such as mould, gaps, leaks or cracking
- Where the property is
- How many joints, rooms or windows are involved
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints.
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Do not run silicone over sand mastic
- Do not paint over the new mastic
- Ask the planning authority about consent for listed or conservation-area homes
- Ask a joiner to look at soft timber first
Leave the new mastic unpainted, which is the traditional advice. Ask us before any decorating around it.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.
DIY sealant or a professional job?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so just mention it when you contact us.
What sand mastic looks like in Bonnington
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. With historic houses such as Westenhanger Castle (about 4.4 miles east) nearby, there’s older building stock in the area around Bonnington 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.
For an older house near a landmark such as Church of St Rumwold, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you let a flat or house near Ham Street station, any sash windows need sound mastic to keep draughts and rain out. Managing a site like Aldington Primary School? Then its window and door frames need their mastic kept sound, just like a home’s.
Bonnington is about 5 miles south-east of Ashford, in Kent. Homes, rented property, offices and hotels in Bonnington is covered for sand mastic. Every job comes with our one-year guarantee. Our area takes in 922 places across Kent, large and small. Crawley is on our list too, around 49 miles away.
Work in TN25 works the same way as everywhere else we cover. Whether your property is on Cherry Orchard Lane and Bourne Road or anywhere close by, our applicators can take on the job. Other places close to Bonnington include Aldington (1 mile north-east), Clap Hill (1 mile north-east), Aldington Frith (1 mile north-west), Stonestreet Green (1 mile north-east) and Postling Green (1 mile east). Within a short drive, we also cover Ashford (5 miles north-west), Canterbury (15 miles north-east), Folkestone (10 miles east), Hythe (7 miles east), Hawkinge (10 miles east) and Wincheap (14 miles north-east).
What’s near Bonnington
Typical jobs here are in homes near Poulton Wood and Walnut Tree Inn. Bonnington’s nearest station is Ham Street station, about 3.6 miles west of the centre. Nearby you’ll also find William Harvey Hospital (3.8 miles north) and Lympne Castle (4.2 miles east). For a walk, there’s Hatch Park.
The process
We keep the work tidy and contained to the area we’re working on. The job generally takes anything from a few hours to a full day, depending on how many windows, and we tell you how long to leave it before we go. In a small place like Bonnington, access is generally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- First, we look at the surrounds with you and agree what needs doing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Deep voids are packed so the mastic is the right thickness.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- We dress the surface so it sits neatly against the masonry.
Preparing for the visit
- Tell us if parking is tricky
- For business premises, tell us about site rules or sign-in
- Tell us about any previous sealing or DIY attempts
Get a quote
Asking for a quote is easy: tell us what needs doing and where and its rough size. A few photos by email make the job easier to understand.