Greater London · England
Sand mastic for sash & case windows in Cowley, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homeowners, landlords and businesses in Cowley. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- A silicone bead on a sash window that spoils the look
- Mastic worn away on windows facing the weather
- Cracked mastic round a front door frame
Sand mastic for homes and businesses in Cowley
Burnt sand mastic is a traditional material that sits naturally against stone and brick. It’s a good fit for period properties, where modern sealant can look out of place. We work on brick reveals, tenement windows and period & listed homes, and the jobs we see most are modern sealant on a period surround and mastic dropping out of the joint.
Many London homes are flats, with windows high above the street. Who looks after the outside of the frames can depend on the lease, so check that first.
A 12-month guarantee comes with the work, just as it does everywhere we cover.
- Place
- Cowley (UB8, UB7, UB10)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
How we quote for sand mastic
We do not publish a price list, because no two jobs are the same. The quote depends on:
- Whether there’s mould to deal with
- The type of sealant required
- Any working-time requirements on site
- How easy the joints are to reach
We don’t show prices on the website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or drop us an email and we’ll talk you through it.
What we need to know
Before you ask for a quote, have a think about:
- Any access issues, like height or stairs
- The address or postcode of the job
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it has been sealed before
Want a quote for sand mastic? Please ring 0345 464 0079 or email us with a few details. You will know what we plan to do, and what it will cost, before any work begins.
Cowley: your questions answered
I let a flat near West Drayton station. Can you help?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can ring 0345 464 0079 or send us an email with the details for a clear quote.
Is Cowley in your area for sand mastic?
Yes, Cowley is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we will give you a clear price.
Do the sealants smell?
There can be a smell while the sealant cures, but it fades. Opening a window helps.
Are you insured?
Yes. We’re fully insured.
Do you guarantee sand mastic work?
All our work has a one-year guarantee.
Will the old sealant be removed?
Yes. All of the old material is cut out and the joint cleaned.
Can I add another job to the visit?
Of course. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Does someone need to be in?
If the work is inside, we need someone to let us in. Once we have agreed the job, you don’t need to watch us work.
The process
On the day, there’s very little for you to do. Show us the job and we will take it from there. The job generally takes a few hours per window, depending on the condition of the joints. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Cowley. A visitor permit or a nearby bay makes the visit run more smoothly.
- We look at the surrounds with you and agree the joints to renew.
- We remove the old, loose mastic.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- The surface is finished to suit the stone or brick.
Preparing for the visit
- Clear the area around the work
- Let us know about earlier repairs to the joints
- Tell us if parking is tricky
Get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Read more
For landlords and businesses
Failed sealant is one of the commonest items on a check-out report. We can quote for more than one property at once.
Letting agents often deal with us directly. Tell us the address, the job and how access works and we’ll quote.
Towns and villages near Cowley
More services for Cowley
What sand mastic looks like in Cowley
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. With historic houses such as Ickenham Hall (about 2.9 miles north-east) nearby, there’s older building stock in the area around Cowley 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.
For site and facilities teams at buildings such as Cowley St Laurence CofE Primary School, its window and door frames need their mastic kept sound, just like a home’s. Cowley is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Cowley is about 2 miles south-west of Hillingdon, in Greater London. From the centre of Cowley to the outskirts, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. Our Greater London coverage runs to 764 places, Cowley among them. There’s also a page for London, about 17 miles away.
We work across the UB8, UB7 and UB10 postcode area for sand mastic. Sand mastic is available to properties on Iver Lane, High Road and The Avenue. We also cover Uxbridge (1 mile north), Yiewsley (1 mile south-east), Hillingdon (2 miles north-east), Thorney (2 miles south) and New Denham (2 miles north). Larger places within reach include City of Westminster (14 miles east), Marylebone (14 miles east), Kensington (12 miles east), Hampstead (13 miles east), Ruislip (5 miles north-east) and Brompton (14 miles east).
Local landmarks in Cowley
We work in homes and buildings around The Crown pub, Uxbridge High School and West Middlesex College. For rail, the closest station is West Drayton station, about 1.3 miles south. Nearby you will also find British Airways Heritage Collection (0.7 miles north-west) and The Chimes (1.3 miles north). Open spaces near Cowley include Uxbridge Moor and Northala Fields.
Aftercare tips
No joint lasts for ever, but care makes a real difference. Our tips:
- Ask a joiner to look at soft timber first
- Check the mastic when you check the paintwork
- Go gently near the mastic when preparing windows
- Avoid patching sand mastic with silicone
Check the mastic when you check the paintwork. Small cracks are easier to deal with early.
It’s best to renew mastic before painting the windows. Paint over cracked mastic only covers it up.
When to call us in Cowley
Decorating can disturb tired mastic. Many people find it crumbling when they prepare the windows.
It’s worth asking for a quote if you see:
- Tired mastic found when preparing windows for paint
- Draughty sash windows at the surround
- Crumbling sand mastic round a window
- Modern sealant on a period surround
If you let a flat or house near West Drayton station, any sash windows need sound mastic to keep draughts and rain out.
Questions to ask before booking
- How long to leave it before use
- How long the guarantee is
- Whether you can choose the colour
- What happens if the job turns out different
What sealant work can’t fix
Before booking, it’s worth knowing the limits too:
- Cracked or broken glass
- Damaged stone surrounds
- Sashes that rattle, stick or will not open
If you’re not sure, just call 0345 464 0079 or send us an email and we will give you a straight answer before you book.
Where we work in Cowley
- Stone surrounds
- Period & listed homes
- Brick reveals
- Timber door frames
- Tenement windows
- Sash and case windows