Hertfordshire · England
Sand mastic for sash & case windows in Oxhey, Hertfordshire
We cover Oxhey 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 and a 12-month guarantee.
- Wind and rain getting in round a sash window
- Mastic dropping out of the joint
- Open joints round the window box
How we handle sand mastic in Oxhey
Across Oxhey, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand for a neat, traditional finish. If you are dealing with draughty sash windows at the surround and crumbling sand mastic round a window, we can help, on tenement windows, brick reveals and sash and case windows alike.
Homes around Oxhey range from older properties to newer houses, and their windows range just as widely. Each frame material needs the right sealant against the right wall.
You’re covered for a year from the day we finish. If there’s a problem with it, please ring 0345 464 0079 or email us.
- Place
- Oxhey (WD23, WD19, WD17)
- Wider area
- Hertfordshire
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
What we are called out for in Oxhey
Paint, silicone or cement used over old mastic causes problems. They don’t suit the joint and we normally remove them.
Keep an eye out for these signs:
- Mastic round period door frames that has failed
- Old cement repairs round a window that have failed
- Weathered mastic on the most exposed windows
- Draughts and rain around sash boxes
Schools such as Bushey Manor Junior School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s.
What your quote should include
- What happens if they find a problem under the old sealant
- Who does the work, and how experienced they are
- How the joint is cleaned and prepared
- What insurance they hold
Oxhey questions
Will you come out to Oxhey?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Do you work for landlords with property near Bushey station?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before work begins.
Can you replace silicone on a period window with sand mastic?
Yes. We remove the silicone and clean the joint before the sand mastic goes in.
Can sand mastic be painted?
It’s traditionally left unpainted, as guidance on traditional windows advises. Ask us before decorating.
Is it OK to seal over old sealant?
No, and we never do. It may look fine at first, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Can you match the sealant colour?
Yes. White, clear and grey are common, and other colours are available for many products, and we agree the colour with you before work begins.
What information do you need?
Just the basics: the address or postcode, what’s wrong and any access issues. After that, simply phone 0345 464 0079 or email us.
Should I check with the council before work on a listed or conservation-area home?
It’s best to ask your local planning authority first. Sand mastic is often favoured as like for like, but they decide.
Oxhey homes and the weather
Historic houses like Headstone Manor (about 3.7 miles south) are a reminder that the area around Oxhey has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. 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.
Rented homes near Bushey station change hands often, and older sash windows in a rental need their mastic kept sound to keep the weather out. In the older streets around Church of St James, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Oxhey is about 1 mile west of Bushey, in Hertfordshire. Across the WD23 area, our applicators can take on sand mastic. Our area takes in 381 places across Hertfordshire. There’s also a page for London, roughly 16 miles from Oxhey.
We work across the WD23, WD19 and WD17 postcode area for sand mastic and the streets around it. You will find streets such as Cow Lane, Vale Road and Park Road, and we cover them all. Oxhey sits on or near the A4008, which makes travel easy. Nearby, we also carry out sand mastic in Watford Heath (1 mile south-west), Bushey (1 mile east), Carpenders Park (1 mile south), Watford (2 miles north-west) and Bushey Heath (2 miles south-east). We also work in nearby towns such as Hemel Hempstead (8 miles north-west), St Albans (8 miles north), Welwyn Garden City (13 miles north-east), Harpenden (12 miles north), Cheshunt (15 miles east) and Hatfield (10 miles north-east).
Around Oxhey
We work in homes and buildings around St. Hilda's School, Oxhey Park and The Bushey Academy, among other places. Oxhey has its own railway station: Bushey station. A little further out are Hertfordshire Fire Brigade Museum (0.7 miles north-west) and Harlequin Centre (1 mile north-west). Not far away are Harrow Weald Common.
More services for Oxhey
Why act early in Oxhey
Replacing sash windows is a big decision for a period home and on a listed home, consent may be needed. If the frames are sound, renewing the mastic deals with gaps and draughts at the surround. Around Oxhey, 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.
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
Why Oxhey clients choose us
- Over 20 years’ experience
- Rated 4.9 stars on Google
- Approved under the ARBOMaster scheme
- Anti-fungal sanitary silicone in wet areas
Take a look at our cost guide and our reviews.
Work for landlords, hotels and businesses
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
Housing providers, facilities teams and property managers book us too in Oxhey and across Hertfordshire. We can quote a run of properties together, and we’re fully insured.
What we do, step by step
There’s no need to move everything out before we come, only the area right around the joints. We protect the rest, and the job takes a few hours per window, depending on the condition of the joints in most cases. Parking around Oxhey is normally easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- First we agree which joints need doing.
- 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.
- We dress the finish so it sits neatly against the masonry.
Preparing for the visit
- Mention any leaks or damp you’ve noticed
- Keep pets and children clear of the area while we work
- Clear the area around the work
Getting a quote
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 pictures if that’s easy.
Advice
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Honest limits
Honest advice matters more to us than a booking, so here’s what sealant can’t fix:
- Timber that has rotted
- Sashes that need overhauling
- Whether work needs listed building consent
If in doubt, call 0345 464 0079 or email us and we’ll say what we think before booking.
Where we work in Oxhey
- Stone surrounds
- Timber door frames
- Period & listed homes
- Tenement windows
- Sash and case windows
- Brick reveals
Different surfaces, different methods
Stone surrounds
Stone openings are rarely perfectly straight, so the joint varies in width. We shape it by hand to follow the stone.
Timber door frames
Doors face weather and wear, so their mastic can fail sooner. We rake it out and renew it.