Greater London · England
Sand mastic for sash & case windows in Farringdon, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for householders, landlords and businesses in Farringdon. Fully insured, ARBOMaster approved and guaranteed for a year.
- Draughts and rain around sash boxes
- Mastic round period door frames that has failed
- Window mastic to renew ahead of painting
What affects the cost of sand mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- The size of the job
- The type of sealant required
- Whether the work is at height
- How many areas need sealing
We don’t show prices on the website, because the cost depends so much on the job itself. Call for a quick quote.
Helping us quote
There’s no need for technical detail. Just tell us:
- Where the job is, and your postcode
- If someone has resealed it before
- What’s wrong with the joints now
- How we’d reach the joints
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we’ll explain what’s involved.
Sand mastic in Farringdon, done properly
Burnt sand mastic is a traditional material that sits naturally against stone and brick. It suits period and listed homes where a modern sealant bead would stand out. We work on period & listed homes, brick reveals and tenement windows, and people most often call us about patchy fillers round a sash window and gaps round a timber door in stone or brick.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. The mastic around them dries out and cracks with age, which is when draughts and damp patches appear in homes in Farringdon.
The work is covered for a year after we finish. If anything isn’t right with it, ring 0345 464 0079 or send us an email.
- Place
- Farringdon (EC1V, EC1R, EC1P)
- Region
- Greater London
- Guarantee
- One year on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Ask us before painting near the mastic
- Look over the window mastic once a year
- Ask a joiner to look at soft timber first
- Keep modern sealant off the mastic
Leave the new mastic alone while it firms up. It skins over quickly, but takes longer to harden fully.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.
Also near Farringdon
What else we do in Farringdon
DIY versus a professional finish
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly.
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.
What we can’t put right
Before you book, it’s worth knowing the limits too:
- Damaged stone surrounds
- Decisions on consent for listed homes
- Putty and glazing repairs
If in doubt, phone 0345 464 0079 or email us and we will say what we think before you book.
Surfaces we seal
- Stone surrounds
- Sash and case windows
- Brick reveals
- Period & listed homes
- Timber door frames
- Tenement windows
What we do, step by step
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes anything from a few hours to a full day, depending on how many windows and we leave things clean and tidy. In a London area like Farringdon, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- Deep gaps are packed so the mastic sits at the right depth.
- The sand mastic is mixed and pressed into the joint by hand.
- We dress the finish so it sits neatly against the masonry.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Let us know about parking restrictions
- Let us know if you’ve seen damp or leaks
Getting a quote
There’s no standard price list, because every job is different. Instead, we give you a clear price for your job. To get started, ring 0345 464 0079 or send us an email.
Advice
Sand mastic in Farringdon: local notes
In London conversions and blocks, the lease decides who is responsible for the frames, so check that before booking. Historic houses like Dr Johnson's House (about 0.4 miles south-west) are a reminder that the area around Farringdon has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
Homes close to St John Clerkenwell include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you let a flat or house near Farringdon station, cracked sand mastic around sash windows lets in the draughts tenants complain about. Farringdon is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Farringdon is about 2 miles north of London, in Greater London. If you need sand mastic in Farringdon, it’s easy to get a quote: please call 0345 464 0079 or drop us an email. We cover Greater London from our Crawley base. Across Greater London, we cover 764 places, and Farringdon is one of them.
Every address in EC1V, EC1R and EC1P is within our area for sand mastic. Whether your property is on Oat Lane, Shoe Lane and Long Lane or anywhere close by, our applicators can take on the job. Being close to the A1 and A4, Farringdon is easy for our applicators to reach for sand mastic. We also cover the places around Farringdon: Smithfield (1 mile south), Clerkenwell (1 mile north), Holborn (1 mile west), Blackfriars (1 mile south) and Temple Bar (1 mile south-west). We also work in nearby towns such as Kensington (4 miles west), Walthamstow (6 miles north-east), Hampstead (4 miles north-west), Ruislip (14 miles west), Brompton (3 miles south-west) and Stockwell (4 miles south).
Landmarks near Farringdon
Typical jobs here are in homes near The Castle Public House, St Mary-at-Hill and Barts Health Archives and the streets around them. You’ll also find St Peter and St Paul RC Primary School (under half a mile north), Barbican Conservatory (less than half a mile east) and Central Foundation Boys' School (0.8 miles east). Farringdon has its own railway station: Farringdon station. A little further out are Museum of the Order of St John (under half a mile north-east) and Gabriel's Wharf (0.9 miles south). Not far away are Ludgate Hill and Barnsbury Wood.
Leave it or put it right?
Draughts round a sash window aren’t always the sashes. Open mastic joints round the box can let air in, and renewing the mastic closes them. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Farringdon, the repair is bigger than the sealant job would have been.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
Why book with us
- Fully insured
- An ARBOMaster approved applicator
- Domestic, commercial and hotel work
- Sanitary silicone with an anti-fungal additive in wet areas
Take a look at our cost guide or our reviews.
For landlords and businesses
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
We work for landlords and letting agents as well as householders. Sealant work between tenants keeps a property looking cared for.
Your questions about sand mastic in Farringdon
Do you cover Farringdon for sand mastic?
Yes, Farringdon is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Can you help a landlord with a rental near Farringdon station?
Yes. We work for letting agents and landlords as well as homeowners. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we’ll give you a clear quote.
Do you work for hotels and businesses?
Yes, regularly. We can plan bigger jobs in stages to suit the site.
Is it OK to seal over old sealant?
No, because it fails. The old sealant always comes out first, so the new joint bonds to clean surfaces.
What do you put in the joint?
We choose the sealant for the joint, not the other way round. Where it moves, gets wet or faces the weather makes a difference, and we will tell you what we’re using.
Can I choose the sealant colour?
Most of the time, yes. We will explain which colours are available and agree one before work begins.
How long will you be here?
Typically it takes anything from a few hours to a full day, depending on how many windows. Larger jobs naturally take longer.
Is it worth trying it myself?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. If it does not work out, we can redo it.