Milton Keynes · England
Sand mastic for sash & case windows in Great Horwood, Milton Keynes
Problem with your window and door surrounds in Great Horwood? We cut out the old, prepare the joints and apply the right sealant, with a one-year guarantee.
- Patchy fillers round a sash window
- Crumbling sand mastic round a window
- Weathered mastic on the most exposed windows
About our sand mastic in Great Horwood
Sand mastic is the traditional way to point the gap between a timber window frame and the stone or brick around it. It’s a mix of sand and a linseed-oil-based binder and built up by hand. On older homes, it suits the building far better than silicone. We’re often asked to deal with mastic that needs renewing before redecorating and crumbling sand mastic round a window, on period & listed homes, sash and case windows and stone surrounds.
Homes in small places like Great Horwood 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.
A one-year guarantee comes as standard.
- Where
- Great Horwood (MK17)
- Wider area
- Milton Keynes
- Guarantee
- 12 months on all our work
- Quote
- A clear price before we start
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Common problems we fix in Great Horwood
Decorating can disturb tired mastic. It’s often found when windows are being prepared for paint, which is a good time to renew it.
The most common problems we see are:
- Draughty sash windows at the surround
- Cracked mastic round a front door frame
- Failed mastic on an exposed elevation
- Window mastic to renew ahead of painting
For an older house near a landmark such as Church of St James, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Comparing quotes
- Who turns up on the day
- How long the guarantee is
- What product goes in the joint
- How long to leave it before use
Also near Great Horwood
Other services in Great Horwood
The process
On the day, we start by going over the job with you, so you know exactly what we’re doing. We protect the surfaces around the joints before any work begins. Most jobs take a few hours per window, depending on the condition of the joints. For a village or hamlet like Great Horwood, the journey is planned in advance: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- We look at the surrounds with you and agree the joints to renew.
- Old mastic and any loose material are raked out.
- 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
- Let us know about earlier repairs to the joints
- On commercial sites, let us know about site rules
- Mention any tricky access
Get a quote
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job.
Advice
What happens if it’s left?
Cement-based fillers and modern sealants don’t always suit a period surround. Sand mastic matches what was there, which can matter on listed and conservation-area homes. Older cottages and farmhouses around Great Horwood can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
We don’t show prices on the website, because each job is priced on what it involves. Call for a quick quote and we’ll talk you through it.
Why choose Mr Mastic in Great Horwood
- Arbo and Everbuild products
- 4.9 on Google from 180+ five-star reviews
- Anti-fungal silicone where joints get wet
- Any old sealant cut out fully, not covered over
Sand mastic in Great Horwood: local notes
Historic houses like Claydon House (about 4.9 miles south-west) are a reminder that the area around Great Horwood has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. 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.
Managing a site like Great Horwood Church of England School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Great Horwood is about 5 miles east of Buckingham, in Milton Keynes. Whether you’re in the middle of Great Horwood or further out, we cover sand mastic for every kind of property. 73 places in Milton Keynes are on our list, large and small. We also work in Oxford, around 22 miles away.
All of MK17 is covered for sand mastic. Whether your property is on High Street, The Green and Willow Road or anywhere close by, our applicators can take on the job. Neighbouring places we cover for sand mastic include Little Horwood (1 mile east), Nash (2 miles north), Winslow (2 miles south), Whaddon (3 miles north-east) and Swanbourne (3 miles south-east). Within a short drive, we also cover Milton Keynes (6 miles north-east), Bletchley (6 miles east), Newport Pagnell (10 miles north-east), Bletchley and Fenny Stratford (7 miles east), Furzton (5 miles north-east) and Whitehouse (5 miles north-east).
Near you in Great Horwood
Typical jobs here are in homes near Sir Thomas Fremantle School and The Crown pub and the streets around them. A little further out are Buckingham Community Hospital (5 miles north-west) and Drayton Parslow Mound (4.2 miles south-east). The countryside around Great Horwood includes Buckingham Sand Pit.
Aftercare tips
How long the joints last depends on use and care. We suggest:
- Make sure water runs off the sill
- Find out about consent before window work on a listed home
- Do not paint over the new mastic
- Take care around the mastic when scraping paint
When preparing windows for paint, take care around the mastic. It can be damaged by heavy scraping.
An open joint round the box lets weather through. The longer it’s left, the more the joint opens as more mastic falls out.
Can I do it myself?
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
What the job involves on each surface
Tenement and terrace windows
In shared buildings, the windows may be part of a wider repair, so check who is responsible first.
Timber door frames
Period doors in stone or brick openings are often pointed with sand mastic. We renew it the same way as on windows.
What sealant work can’t fix
In fairness, there are a few things sealant won’t fix:
- Rotten sashes, sills or window boxes (a joiner’s job)
- Whether work needs listed building consent
- Sash cords, weights and draught-proofing of the sashes
If you are not sure, just phone 0345 464 0079 or drop us an email and we will give you a straight answer before booking.
Where we work in Great Horwood
- Tenement windows
- Timber door frames
- Stone surrounds
- Brick reveals
- Sash and case windows
- Period & listed homes
Questions from Great Horwood
Is sand mastic in Great Horwood guaranteed?
All our work, in Great Horwood and everywhere else, comes with a 12-month guarantee. We are also fully insured and ARBOMaster approved.
Is Great Horwood in your area for sand mastic?
Yes. We work across London and the South East, and Great Horwood is part of that. You can ring 0345 464 0079 or send us an email and tell us what needs doing.
Will it make a mess?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
Is sand mastic better than silicone for my windows?
We will talk it through with you. Period homes often look best with sand mastic, and modern sealants suit newer frames.
Can you quote for more than one area?
Yes, and it often makes sense. Doing several areas at once is generally more efficient, so mention them when you ask for a quote.
Do you remove the old sealant?
Yes, every time. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
Is it possible to paint over sand mastic?
Sand mastic is normally left unpainted, as guidance on traditional windows advises. Ask us before decorating.
What information do you need?
Let us know what needs doing and where, with photos by email if possible. We’ll ask anything else we need to know.