Greater London · England
Sand mastic for sash & case windows in Barnsbury, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homes and businesses in Barnsbury and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- A silicone bead on a sash window that spoils the look
- Cracked mastic round a front door frame
- Weathered mastic on the most exposed windows
Keeping the joints in good condition
So the new joints stay in good condition:
- Inspect the joints round the windows every year or so
- Find out about consent before window work on a listed home
- Leave the new mastic unpainted
- Get any rot dealt with first
Do not run silicone over the new mastic. If you see a crack, ask us to take a look before trying a quick fix.
Crumbling mastic lets rain into the joint. It can soak into the frame and the surrounding masonry so early renewal protects both.
About our sand mastic in Barnsbury
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. Common call-outs are for silicone on a period window that looks wrong and old cement repairs round a window that have failed, across tenement windows, brick reveals and period & listed homes.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. Over the years, the sealant around them shrinks, cracks and pulls away, which is when draughts and damp patches appear in homes in Barnsbury.
Our work is backed for twelve months.
- Place
- Barnsbury (N1, N1P, N7)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What the job involves on each surface
Stone surrounds
Sand mastic sits naturally against stone. The finish blends with the masonry.
Tenement and terrace windows
Windows above ground floor need the right access. Tell us the height and we will confirm what’s needed.
What we’re called out for in Barnsbury
Decorating can disturb tired mastic. It’s often found when windows are being prepared for paint.
If you can see any of these, it’s time to have the joints looked at:
- Modern sealant on a period surround
- Mastic that needs renewing before redecorating
- Cement or filler used on old window joints that has cracked
- Wind and rain getting in round a sash window
As a London address, Barnsbury can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Before booking anyone
- How the colour is chosen
- What happens if they find a problem under the old sealant
- Whether all the old sealant comes out first
- What preparation is included
How we quote for sand mastic
There’s no set price list. The quote depends on:
- Mould in or behind the old joints
- Access and height
- The number of rooms or windows
- The type of sealant required
The cost depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before we start.
Asking for a quote
Photos by email are helpful but not essential. Please mention:
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
- Whether it has been sealed before
- Any access issues, like height or stairs
Every job is quoted individually, so the first step is telling us about yours. Simply phone 0345 464 0079 or email us and describe the job and send pictures if you have them.
Barnsbury questions
Can parking be tricky for a visit in Barnsbury?
In much of London, parking needs planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Can you help a landlord with a rental near Caledonian Road & Barnsbury station?
Yes, landlords and agents are among the people we work for. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we will give you a clear quote.
Can you quote for more than one area?
Yes. Several rooms, windows or areas can go on one quote.
Which products do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We explain the product when we quote.
Will the old sealant be removed?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
Are you fully insured?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Are you an approved applicator?
Yes. We’re an ARBOMaster approved applicator, which is run for the Arbo sealant brand.
Is it possible to paint over sand mastic?
The usual advice is to leave sand mastic unpainted. Ask us before you decorate around it and we will talk you through it.
The process
There’s no need to move everything out before we come, just the space around the work. Everything nearby is protected, and the work takes a few hours per window, depending on the condition of the joints for a typical job. In Barnsbury, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We look at the surrounds with you and agree the joints to renew.
- 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.
- The surface is finished to suit the stone or brick.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Keep pets and children clear of the area while we work
- Let us know about earlier repairs to the joints
Getting a quote
Need a quote? Please phone 0345 464 0079 or drop us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Advice
What sealant work cannot fix
We will always be straight with you, so here’s what new sealant won’t do:
- Damaged stone surrounds
- Sashes that rattle, stick or will not open
- Putty and glazing repairs
If you’re not sure, just ring 0345 464 0079 or drop us an email and we’ll give you a straight answer before you book.
Joints and surfaces we work on
- Period & listed homes
- Sash and case windows
- Timber door frames
- Tenement windows
- Brick reveals
- Stone surrounds
Why act early in Barnsbury
Before painting the windows, it pays to renew the mastic. Painting over failed mastic does not seal it, and the new mastic is traditionally left unpainted. In London conversions, one flat’s bathroom is often above another flat’s ceiling, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble for homes in Barnsbury.
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
Why choose Mr Mastic in Barnsbury
- Domestic, commercial and hotel work
- Rated 4.9 stars on Google
- 12-month guarantee on every job
- We leave the area clean and tidy
Take a look at our cost guide and our reviews.
Towns and villages near Barnsbury
Also in Barnsbury
Sand mastic in Barnsbury: local notes
With historic houses such as Dr Johnson's House (about 2.1 miles south) nearby, there’s older building stock in the area around Barnsbury 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’s traditional sand mastic. In a converted house or block, who looks after the windows depends on the lease, so check that before booking.
For an older house near a landmark such as Former Church of St Clement, 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 Caledonian Road & Barnsbury station, any sash windows need sound mastic to keep draughts and rain out.
Barnsbury is about 1 mile north of St Pancras, in Greater London. Every kind of property in Barnsbury is covered for sand mastic. Every job comes with our one-year guarantee. Barnsbury is one of 764 towns and villages in Greater London where we work for sand mastic.
All of N1, N1P and N7 is covered for sand mastic. If you need sand mastic at a property on Cliff Road, Lough Road and North Road or a nearby road, we can help. Barnsbury sits on or near the A5200 and A5203, which makes travel easy. Other places close to Barnsbury include Lower Holloway (1 mile north), Islington (1 mile south-east), Agar Town (1 mile south-west), Pentonville (1 mile south-east) and Holloway (1 mile north). Within a short drive, we also cover London (3 miles south), City of Westminster (3 miles south-west), Kensington (5 miles south-west), Walthamstow (5 miles north-east), Whitechapel (3 miles south-east) and Hampstead (3 miles west).
Local landmarks in Barnsbury
Around Barnsbury, our work takes us to homes and buildings near Vaughan Williams Memorial Library, St Mary Magdalene Academy and Bingfield Park, among other places. Other local landmarks include Musical Theatre Academy (0.5 miles north-east) and The White Horse Public House (within half a mile north-west). Barnsbury has its own railway station: Caledonian Road & Barnsbury station. Other landmarks nearby include Brunswick Centre (1.4 miles south) and Montfichet's Tower (2.2 miles south). Green spaces nearby include Dartmouth Park Hill and Barnsbury Wood.