Greater London · England
Sand mastic for sash & case windows in Blackfriars, Greater London
We cover Blackfriars for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Old sand mastic that has cracked, crumbled or fallen out
- Modern sealant on a period surround
- Gaps between timber frames and stone or brick
About our sand mastic in Blackfriars
On many period windows, sand mastic looks right and suits the building. On modern frames we’d normally use a flexible sealant and we’ll explain which is best for yours. If you are dealing with mastic round period door frames that has failed and draughts and rain around sash boxes, we can put it right, on sash and case windows, tenement windows and brick reveals alike.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
The work is covered for a year after we finish. If anything isn’t right with it, ring 0345 464 0079 or email us.
- Where
- Blackfriars (SE1, EC1M, EC1N)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
DIY sealant or a professional job?
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. 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.
What affects the quote in Blackfriars
We don’t publish a price list. The quote depends on:
- How many areas need sealing
- The size of the job
- Whether old sealant or filler has to be cut out
- The type of sealant required
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, along with when we can work on site. Ask us for a quote and we will go through it with you.
What to tell us for a quote
To help us quote quickly, please include:
- Access, such as stairs, a lift or height
- Roughly how big the job is
- What’s wrong with the joints now
- A few photos by email, if you can
Want a quote for sand mastic? Please call 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and give you a clear quote before work begins.
What sand mastic looks like in Blackfriars
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. With historic houses such as Dr Johnson's House (about 0.2 miles north-west) nearby, there’s older building stock in the area around Blackfriars as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
As a London address, Blackfriars can be tricky for parking: let us know about parking bays, permits or a driveway. In the older streets around St Ann Blackfriars, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Blackfriars is about 1 mile north-west of London, in Greater London. Blackfriars gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. Blackfriars is one of 764 places in Greater London where we work for sand mastic.
We work across SE1, EC1M and EC1N for sand mastic and the streets around it. If you need sand mastic at a property on Oat Lane, Bear Lane and Shoe Lane or anywhere close by, we can help. Blackfriars sits on or near the A4 and A40, which makes travel easy. Other places close to Blackfriars include Temple (1 mile west), Temple Bar (1 mile west), Bankside (1 mile south-east), Smithfield (1 mile north) and Clare Market (1 mile 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 (3 miles south).
Landmarks near Blackfriars
In Blackfriars, that means homes and buildings near Barts Health Archives, St Mary-at-Hill and St Alban's Church of England Primary School and the streets around them. Nearby too are Bernie Spain Gardens (less than half a mile south-west), London Nautical School (0.5 miles south-west) and The Black Friar pub (less than half a mile south-east). Blackfriars has its own railway station: London Blackfriars station. Well-known places in the area include Montfichet's Tower (within half a mile north-east) and St Brides Crypt Museum (within half a mile north-west). Not far away are Barnsbury Wood and St. James's Park Lake.
What we’re called out for in Blackfriars
Rain on the window surround works into any crack and pushes it out. Exposed elevations generally fail first.
Look out for these signs:
- Draughty sash windows at the surround
- Patchy fillers round a sash window
- Mastic that needs renewing before redecorating
- Modern sealant on a period surround
For landlords with property near London Blackfriars station, any sash windows need sound mastic to keep draughts and rain out.
What your quote should include
- Are they insured?
- How long to leave it before use
- How long the guarantee is
- Which colour the sealant will be
What we can’t put right
In fairness, there are a few things sealant won’t fix:
- Sashes that need overhauling
- Timber that has rotted
- Whether work needs listed building consent
If in doubt, call 0345 464 0079 or drop us an email and we’ll say what we think.
Surfaces we seal
- Stone surrounds
- Sash and case windows
- Brick reveals
- Timber door frames
- Tenement windows
- Period & listed homes
Also near Blackfriars
More services for Blackfriars
Different surfaces, different methods
Stone surrounds
Stone surrounds suit sand mastic well. It finishes to look like part of the surround.
Sash and case windows
On a sash window, the mastic joint shows on the outside, so a neat, even finish matters.
Why deal with it now?
A silicone bead can be quicker, but on period stone or brick it often looks out of place. Sand mastic suits the building and blends with the stone or brick. Damp from a failed joint spreads quietly in older London brickwork and timber, and once it shows in Blackfriars, the repair is bigger than a sealant job.
Rather than a set price list, we look at what your job involves: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Why book with us
- Old sealant always removed completely
- Quality sealants from Arbo and Everbuild
- Over 20 years’ experience
- Approved under the ARBOMaster scheme
Read our cost guide and what customers say.
Blackfriars: your questions answered
I let a flat near London Blackfriars station. Can you help?
Yes, we work for landlords and agents. Just phone 0345 464 0079 or email us and tell us about the property, and we will send you a clear quote.
Is parking an issue for sand mastic in Blackfriars?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Are you an approved applicator?
Yes. We’re approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
What should I tell you?
Only a few details: the address or postcode, what’s wrong and any access issues. Then ring 0345 464 0079 or drop us an email.
Are you fully insured?
Yes, we are fully insured.
How long will you be here?
Typically it takes a few hours for a single window, longer for several. Larger jobs naturally take longer, and we will say how long yours will take.
Can I add another job to the visit?
Yes. Just list everything you need and we’ll quote it together.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. Once we have agreed the job, you don’t need to watch us work.
How it works
At the end, we look at the finished work together. The visit itself normally takes a few hours per window, depending on the condition of the joints, depending on how much there is to do. For a job in Blackfriars, parking and access are the things to plan: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- First we agree which joints need doing.
- 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.
Before we arrive
- Keep pets and children clear of the area while we work
- Let us know about earlier repairs to the joints
- Move anything stored near the joints
Getting a quote
For sand mastic in Blackfriars, ring 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and we’ll agree the price before any work begins.