Oxfordshire · England
Sand mastic for sash & case windows in Crawley, Oxfordshire
Sand mastic in Crawley from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Wind and rain getting in round a sash window
- Failed mastic on an exposed elevation
- Mastic that needs renewing before redecorating
Work for landlords, hotels and businesses
For anyone letting property in or around Crawley, jobs at different addresses can be quoted together. Send us the addresses and the work at each.
Hotels need rooms back in use, so we plan the work room by room. Hotel work is part of what we do, alongside homes and businesses.
About our sand mastic in Crawley
Across Crawley, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand, finished to suit the masonry. Typical jobs include gaps where the frame meets the masonry and draughty sash windows at the surround, on period & listed homes, stone surrounds and tenement windows.
Homes in small places like Crawley often stand in the open, with little to shelter their windows from wind and rain. That exposure dries out and cracks the mastic around frames and sills faster.
Big or small, you get the same 12-month guarantee in Crawley and across Oxfordshire.
- Place
- Crawley (OX29)
- Wider area
- Oxfordshire
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
How to look after the new joints
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Check the mastic when you check the paintwork
- Find out about consent before window work on a listed home
- Keep sills and gutters clear so water drains away
- Get any rot dealt with first
When preparing windows for paint, take care around the mastic. Hard scraping can loosen it.
Renewing mastic before redecorating saves doing it twice. Paint over cracked mastic only covers it up.
Crawley homes and the weather
With historic houses such as Minster Lovell Hall (about 1.1 miles west) nearby, there’s older building stock in the area around Crawley 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. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you look after a building such as Hailey Church of England Primary School, larger buildings have plenty of frames, and the mastic around each one ages. If you let a flat or house near Finstock station, any sash windows need sound mastic to keep draughts and rain out. For an older house near a landmark such as Church of St John the Evangelist, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Crawley is about 1 mile north-west of Witney, in Oxfordshire. Every kind of property in Crawley is covered for sand mastic. Every job comes with our one-year guarantee. Our Oxfordshire coverage runs to 443 places, Crawley among them. Our Oxford page covers work nearby (12 miles or so).
All of OX29 is covered for sand mastic. If you need sand mastic at a property on Witney Hill, Farm Lane and Foxburrow Lane or anywhere close by, we can help. Other places close to Crawley include Leafield (2 miles north-west), Swinbrook (4 miles west), Ascott d'Oyley (4 miles north-west), Ascott-under-Wychwood (5 miles north-west) and Ascott Earl (5 miles north-west). We also work in nearby towns such as Oxford (12 miles east), Abingdon-on-Thames (13 miles south-east), Carterton (5 miles south-west), Wantage (15 miles south), Grove (14 miles south) and Faringdon (11 miles south).
Near you in Crawley
In Crawley, that means homes and buildings near Wood Green School and The Lamb Inn, among other places. For rail, the closest station is Finstock station, about 3.6 miles north-east of the centre. Well-known places in the area include Cogges Manor Farm Museum (1.9 miles south-east). Green spaces nearby include Blenheim Farm.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and getting the depth right matters as much as the look.
What we cannot put right
We’ll always be straight with you, so here’s what sealant cannot fix:
- Decisions on consent for listed homes
- Damaged stone surrounds
- Sash cords, weights and draught-proofing of the sashes
If you are not sure, just call 0345 464 0079 or send us an email and we will give you a straight answer before booking.
What we seal
- Tenement windows
- Brick reveals
- Sash and case windows
- Timber door frames
- Period & listed homes
- Stone surrounds
How we quote for sand mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- How many areas need sealing
- Any mould that needs treating
- Whether the work is at height
- Any working-time requirements on site
Every job is a little different, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all play a part, and we will explain the quote if you ask.
Asking for a quote
Photos help, but a description is a good start. Try to tell us:
- Where the job is, and your postcode
- Pictures of the joints, sent by email
- How we’d reach the joints
- Roughly how big the job is
To get a quote, call 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. You will have a clear quote before any work starts.
Why it’s worth doing now in Crawley
Not every filler suits an old window surround. Sand mastic matches what was there, which can matter on listed and conservation-area homes. Older cottages and farmhouses around Crawley can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
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.
Why choose Mr Mastic in Crawley
- Every job guaranteed for a year
- 180+ five-star Google reviews
- Sanitary silicone with an anti-fungal additive in wet areas
- Any old sealant cut out fully, not covered over
The process
When we arrive, we start by going over the job with you. We protect the surfaces around the joints before any work starts. Most jobs take anything from a few hours to a full day, depending on how many windows. In a small place like Crawley, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, we look at the surrounds with you and agree what needs doing.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic is not too thick.
- The mastic is mixed, pressed into the joint by hand and shaped.
- We dress the surface so it sits neatly against the masonry.
Preparing for the visit
- Keep children and pets away from the work area
- Clear items away from the joints we are working on
- Try not to wet indoor joints just before the visit
Getting a quote
Need a quote? Please phone 0345 464 0079 or send us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Related advice
Your questions about sand mastic in Crawley
Do you cover Crawley for sand mastic?
Yes. We work across London and the South East, and Crawley is part of that. You can ring 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear price.
Do you work for landlords with property near Finstock station?
Yes, landlords and agents are among the people we work for. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we’ll give you a clear price.
Can I paint the new mastic?
It’s traditionally left unpainted, which is what traditional guidance recommends. Talk to us before any painting near it.
Is consent needed for window work on a listed home?
Check with your local planning authority. They decide whether consent is needed for work to your windows.
Is it worth trying it myself?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
Where is Mr Mastic based?
Our base is Crawley. We work across South East England, London and Scotland.
Can you replace silicone on a period window with sand mastic?
Yes, we do this often. All the old silicone is removed first so the mastic beds in well.
Which is right for my windows, sand mastic or modern sealant?
We’ll talk it through with you. Period homes often look best with sand mastic, and modern sealants suit newer frames.