Buckinghamshire · England
Sand mastic for sash & case windows in Longwick, Buckinghamshire
We cover Longwick for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- A silicone bead on a sash window that spoils the look
- Mastic worn away on windows facing the weather
- Draughts and rain around sash boxes
Should I try it myself first?
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
Sand mastic in Longwick, done properly
Our applicators renew the sand mastic around sash and case windows and doors in stone and brick. Out comes the old, loose mastic, and new mastic is applied and shaped by hand. If you have mastic that needs renewing before redecorating and silicone on a period window that looks wrong, we can help, whatever the surface.
Around Longwick, conservatories, garden rooms and patio doors are often part of the house. Those joints need the same attention as the main windows.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Where
- Longwick (HP27)
- Region
- Buckinghamshire
- Cover
- One year on every job
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
What sand mastic looks like in Longwick
Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For an older house near a landmark such as Owlswick Chapel, frames set in older brick or stone need a sealant that suits the wall as well as the frame. If you let a flat or house near Monks Risborough station, cracked sand mastic around sash windows lets in the draughts tenants complain about.
Longwick is about 5 miles east of Thame, in Buckinghamshire. Whether you’re in the middle of Longwick or further out, sand mastic is available for homes and businesses alike. Longwick is one of 263 towns and villages in Buckinghamshire where we work for sand mastic. Oxford is on our list too, around 16 miles away.
Postcode districts we cover here for sand mastic: HP27. Whether your property is on Headland End, Wickfields and Furrow Drive or anywhere close by, our applicators can take on the job. We also cover the places around Longwick: Owlswick (1 mile north), Alscot (1 mile east), Pitch Green (1 mile south-west), Ilmer (1 mile north-west) and Horsenden (1 mile south). We also work in nearby towns such as Aylesbury (6 miles north), High Wycombe (9 miles south-east), Chesham (11 miles east), Marlow (12 miles south), Amersham (12 miles east) and Beaconsfield (13 miles south-east).
Local landmarks in Longwick
Around Longwick, our work takes us to homes and buildings near Princes Risborough School and The Red Lion Public House and the streets around them. The closest station to Longwick is Monks Risborough station, about 1.3 miles east of the centre. Nearby you’ll also find Great Kimble Dial Hill (2.4 miles east) and St John's Hospital (4.6 miles north). Not far away are Brush Hill Local Nature Reserve and Beacon Hill.
Aftercare tips
Aftercare is simple:
- Inspect the joints round the windows every year or so
- Find out about consent before window work on a listed home
- Get any rot dealt with first
- Leave the new mastic unpainted
When preparing windows for paint, take care around the mastic. Hard scraping can loosen it.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry so early renewal protects both.
Signs you need sand mastic in Longwick
Most of it is simply age. Even well-laid mastic needs renewing in time and how long it lasts depends on the weather it faces.
Keep an eye out for any of the following:
- A silicone bead on a sash window that spoils the look
- Weathered mastic on the most exposed windows
- Gaps between timber frames and stone or brick
- Mastic round period door frames that has failed
If you look after a building such as Longwick Church of England Combined School, the mastic around its windows and doors needs looking after like any other building’s.
Comparing quotes
- How the colour is chosen
- Who does the work, and how experienced they are
- Is the old sealant removed completely?
- Which sealant they’ll use, and why
FAQs for Longwick
I let a flat near Monks Risborough station. Can you help?
Yes. We work for landlords and letting agents as well as householders, and several properties can be quoted together. You can phone 0345 464 0079 or email us with the details for a clear quote.
Do you cover Longwick for sand mastic?
Yes, Longwick is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job.
Does someone need to be in?
For indoor joints, yes, someone needs to let us in. Once we’ve agreed the job, you do not need to watch us work.
Do you do commercial work?
Yes. We can plan bigger jobs in stages.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
Is there any odour?
There can be a smell while the sealant cures, which fades as it sets. Opening a window helps.
Where is Mr Mastic based?
We work from Crawley. Our applicators cover Longwick, along with the rest of our area.
Do you remove the old sealant?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
Different surfaces, different methods
Brick reveals
Brick reveals round timber windows are often pointed with sand mastic. It gives a traditional finish.
Tenement and terrace windows
Upper-floor windows need access planning. Let us know the floor and we’ll confirm access.
Quotes for sand mastic in Longwick
Every job gets its own quote. This is what makes a difference:
- How easy the joints are to reach
- The old material and how stubborn it is
- Any working-time requirements on site
- Whether there’s mould to deal with
Combining jobs into one visit is generally more efficient than separate visits. We’ll send you a clear quote for the lot.
What we need to know
To make quoting easier, let us know:
- Where the job is, and your postcode
- What the problem is, such as mould, gaps, leaks or cracking
- Photos by email, if that is easy
- The type of property
If you are in Longwick and need sand mastic, call 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you’ll get a clear quote before any work starts.
What we do, step by step
On the day, we start by going over the job with you, so you know exactly what we are doing. Surfaces next to the work are protected before work begins. Most jobs take a few hours per window, depending on the condition of the joints. In a smaller place like Longwick, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Getting ready for the visit
- Mention any leaks or damp you’ve noticed
- Let us know about stairs, lifts or work at height
- Keep children and pets away from the work area
Ask for a quote
Every job is quoted individually, so the first step is telling us about yours. Simply call 0345 464 0079 or send us an email and describe the job.
Advice
Why act early in Longwick
New sash windows are a major, costly change and on a listed home, consent may be needed. Where the frames are in good order, new mastic seals the surround. Around Longwick, water from a failed joint in an older home can soak into timber and plaster, and that is a much bigger job than renewing the sealant.
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
What you get with us
- A 12-month guarantee on all work
- Anti-fungal sanitary silicone in wet areas
- Full insurance on every job
- Over 20 years’ experience
Take a look at how sealant jobs are priced and what customers say.