Buckinghamshire · England
Calvert Sand Mastic
We cover Calvert for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Mastic dropping out of the joint
- Modern sealant on a period surround
- Cracked mastic round a front door frame
How we handle sand mastic in Calvert
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 and built up by hand. On period homes, it looks right where silicone wouldn’t. If you’re dealing with mastic round period door frames that has failed and draughty sash windows at the surround, we can help, on timber door frames, sash and case windows and stone surrounds alike.
Homes in small places like Calvert often stand in the open, with little to shelter their windows from wind and rain. Exposed frames and sills lose their mastic sooner than sheltered ones.
You’re covered for a year from the day we finish. If there’s a problem with it, please phone 0345 464 0079 or drop us an email.
- Location
- Calvert (MK18)
- Wider area
- Buckinghamshire
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
How we quote for sand mastic
Every job gets its own quote. This is what makes a difference:
- How much there is to do
- Any mould that needs treating
- When we can work, for business premises
- How many areas need sealing
The cost depends on the size of the job, how much old material has to come out and access to the work. You’ll have a clear quote before any work starts.
Helping us quote
To make quoting easier, please include:
- Whether it’s a home or a business
- Any access issues, like height or stairs
- Where the job is, and your postcode
- Roughly how big the job is
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that is easy.
DIY sealant or a professional job?
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so just mention it when you contact us.
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.
Places near Calvert
Other services in Calvert
What sealant work cannot fix
Sealant is not the answer to every problem, and we’ll tell you before any work starts. Sealant will not put right:
- Whether work needs listed building consent
- Broken panes
- Crumbling stone or brickwork round the window
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly.
Where we work in Calvert
- Period & listed homes
- Sash and case windows
- Brick reveals
- Stone surrounds
- Tenement windows
- Timber door frames
Calvert homes and the weather
Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Claydon House (about 2.1 miles east) nearby, there’s older building stock in the area around Calvert as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
If you live in an older home near Church of St Michael, frames set in older brick or stone need a sealant that suits the wall as well as the frame. In and around Calvert, as anywhere, good sand mastic starts with a clean, dry, properly prepared joint.
Calvert is about 6 miles south of Buckingham, in Buckinghamshire. Whether you are in the middle of Calvert or further out, sand mastic is available for homes and businesses alike. Calvert is one of 263 towns and villages in Buckinghamshire where we work. You can also see our page for Oxford, about 15 miles away.
Our applicators cover all of MK18 for sand mastic and the streets around it. If you need sand mastic at a property on Heathers Close, Rustics Close and Sandy Road or a nearby road, we can help. Other places close to Calvert include Charndon (1 mile west), Twyford (2 miles north-west), Poundon (3 miles west), Marsh Gibbon (3 miles west) and Hillesden (3 miles north). We also work in nearby towns such as Aylesbury (10 miles south-east), Buckingham (6 miles north), Elmhurst (10 miles south-east), Southcourt (11 miles south-east), Princes Risborough (15 miles south-east) and Haydon Hill (9 miles south-east).
Near you in Calvert
For a walk, there’s Calvert Jubilee.
Keeping the joints in good condition
Good habits help new joints last longer. Our tips:
- Ask the planning authority about consent for listed or conservation-area homes
- Make sure water runs off the sill
- Go gently near the mastic when preparing windows
- Leave the new mastic unpainted
Avoid sealing over the mastic with silicone. If you see a crack, ask us to take a look rather than patching it.
It’s best to renew mastic before painting the windows. Paint over cracked mastic only covers it up.
What the job involves on each surface
Stone surrounds
Stone surrounds suit sand mastic well. It finishes to look like part of the surround.
Brick reveals
Gaps between frame and brick let in rain and draughts. New mastic seals the gap.
Your questions about sand mastic in Calvert
What guarantee comes with sand mastic in Calvert?
All our work, in Calvert and everywhere else, comes with a 12-month guarantee. We’re fully insured, and an ARBOMaster approved applicator.
Can you do sand mastic in Calvert?
Yes, Calvert is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or drop us an email and tell us what needs doing, and we will send you a clear quote.
Can you seal over the old sealant?
No, because it fails. The old sealant always comes out first.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint before resealing.
Can sand mastic be painted?
Sand mastic is normally left unpainted, which is what traditional guidance recommends. Talk to us before any painting near it.
Do you work for hotels and businesses?
Yes. Commercial and hotel work is a large part of what we do. Working times can be discussed when we quote.
Should I try DIY first?
It depends on the job. High-level, external movement and fire-rated joints are professional jobs.
Which products do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
What happens on the day
All our tools and materials come with us in the van. Once we’ve agreed what’s being done, we protect the area and start. Most jobs take a few hours per window, depending on the condition of the joints. For a village or hamlet like Calvert, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- The surface is finished to suit the stone or brick.
Before we arrive
- Mention if the joints have been sealed before
- Mention any tricky access
- Clear items away from the joints we’re working on
Getting a quote
If you are in Calvert and need sand mastic, call 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
Related advice
What happens if it’s left?
A silicone bead can be quicker, but it can look wrong on a period surround. Sand mastic is the traditional material and finishes neatly against the masonry. Where a wall is exposed, as many are in small places like Calvert, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or send us an email.
What you get with us
- 4.9 on Google from 180+ five-star reviews
- Trusted Arbo and Everbuild sealants
- Full insurance on every job
- Every job guaranteed for a year
See our cost guide or our reviews.