Greater London · England
Sand mastic for sash & case windows in Bloomsbury, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homeowners, landlords and businesses in Bloomsbury. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Window mastic to renew ahead of painting
- Crumbling sand mastic round a window
- Wind and rain getting in round a sash window
How the job changes by surface
Period and listed homes
Materials matter on listed and conservation-area homes. Sand mastic is often the preferred finish.
Sash and case windows
Most of our sand mastic work is on sash windows. We renew the mastic round each box.
Sand mastic in Bloomsbury, done properly
Old sand mastic cracks, crumbles and falls out over time and gaps open up round the frame. Renewing it closes the gap so the surround looks right again. If you are dealing with patchy fillers round a sash window and mastic that needs renewing before redecorating, we can help.
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 Bloomsbury.
All of our work is guaranteed for twelve months.
- Where
- Bloomsbury (NW1W, W1T, NW1)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Places near Bloomsbury
Also in Bloomsbury
Bloomsbury questions
Can parking be tricky for a visit in Bloomsbury?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Is Bloomsbury in your area for sand mastic?
Yes, Bloomsbury is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear quote.
Will there be a smell?
That depends on the sealant. Some smell for a while, some hardly at all.
How do I get a quote for sand mastic in Bloomsbury?
We do not publish prices, because the cost depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Is it possible to take out silicone and use sand mastic instead?
Yes. The silicone is cut out and the joint cleaned, then point it with sand mastic.
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, and we’ll tell you how long to expect.
What is sand mastic?
It’s sand mixed with a linseed-oil-based binder for the joint between timber frames and masonry.
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.
Bloomsbury homes and the weather
In a converted house or block, who looks after the windows depends on the lease, so check that before you book. Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Homes close to St George the Martyr Holborn include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. As a London address, Bloomsbury can be tricky for parking: let us know about parking bays, permits or a driveway.
Bloomsbury is about 1 mile north-east of City of Westminster, in Greater London. For sand mastic in and around Bloomsbury, it’s easy to get a quote: please call 0345 464 0079 or email us. We are based in Crawley and cover Greater London. Our area takes in 764 places across Greater London.
Jobs for sand mastic in NW1W, W1T and NW1 is quoted and booked the same way as anywhere else. If you need sand mastic at a property on Drury Lane, Euston Road and Duke's Road or a nearby road, we can help. You’ll find Bloomsbury on the A401 and A501, so it’s easy for us to get to with everything needed for sand mastic. Other places close to Bloomsbury include St Pancras (1 mile north-east), Euston (1 mile north-west), Kings Cross (1 mile north), Holborn (1 mile east) and Fitzrovia (1 mile west). Within a short drive, we also cover Kensington (4 miles south-west), Walthamstow (6 miles north-east), Hampstead (3 miles north-west), Ruislip (13 miles west), Brompton (3 miles south-west) and Stockwell (4 miles south).
Landmarks near Bloomsbury
Around Bloomsbury, our work takes us to homes and buildings near Lincoln's Inn Fields, Pilsudski Institute of London and St George the Martyr Church of England Primary School. Other local landmarks include Queens Larder Public House (within half a mile south-east) and Maria Fidelis Catholic School FCJ (0.6 miles north-west). Bloomsbury’s nearest station is London Euston station, about 0.6 miles north-west of the centre. Well-known places in the area include Montfichet's Tower (1.2 miles south-east) and National Hospital for Neurology and Neurosurgery (within half a mile south-east). Green spaces nearby include Barnsbury Wood and Ludgate Hill.
What we are called out for in Bloomsbury
Timber frames move with the seasons. The movement cracks the mastic over time.
These are the problems we’re asked about most:
- Old sand mastic that has cracked, crumbled or fallen out
- Draughty sash windows at the surround
- Mastic round period door frames that has failed
- Patchy fillers round a sash window
Schools such as UCL School of Slavonic and East European Studies are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
What your quote should include
- Which colour the sealant will be
- Is VAT in the price?
- Whether all the old sealant comes out first
- Whether the sealant suits the joint
Why deal with it now?
Not every filler suits an old window surround. Sand mastic matches what was there and that can be important for listed homes. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
A few things move the cost up or down: 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 us?
- Trusted Arbo and Everbuild sealants
- 4.9 on Google from 180+ five-star reviews
- Old sealant always removed completely
- Fully insured
Read how sealant jobs are priced or our reviews.
The process
Once we are on site, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. Most jobs then take anything from a few hours to a full day, depending on how many windows. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Bloomsbury. It helps if you can point us to a visitor permit or a bay close to the door.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- We dress the finish so it sits neatly against the masonry.
Before we arrive
- Mention any sign-in or site rules at work premises
- Let us know about stairs, lifts or work at height
- Let us know about earlier repairs to the joints
How to get a quote
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job, and we will take it from there.
Advice
Work for landlords, hotels and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
What affects the quote in Bloomsbury
For a quick quote, just ask. What matters most is:
- The old material and how stubborn it is
- Any mould that needs treating
- Access and height
- Working hours on commercial sites
What you pay reflects the work, not guesswork. That is why we ask about the job first.
What we need to know
What to tell us when you ask for a quote:
- The type of property
- Where the job is, and your postcode
- Any previous sealing or DIY work
- A few pictures by email, if you can
Need a quote? Please ring 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.
Looking after it afterwards
Aftercare is simple, and it makes a real difference:
- Leave the new mastic unpainted
- Keep modern sealant off the mastic
- Check the mastic when you check the paintwork
- Keep sills and gutters clear so water drains away
Look at the mastic when you look over the windows. Small cracks are easier to deal with early.
Gaps round a sash box let in draughts and rain. The longer it’s left, the more the joint opens as more mastic falls out.