Greater London · England
Sand mastic for sash & case windows in Millbank, Greater London
Specialist sand mastic for Millbank: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Silicone on a period window that looks wrong
- Mastic that needs renewing before redecorating
- Gaps round a timber door in stone or brick
How we handle sand mastic in Millbank
Fresh sand mastic forms a skin quite soon, but it takes longer to harden fully. Traditionally, sand mastic is left unpainted, so ask us before you decorate. We work on stone surrounds, brick reveals and sash and case windows, and common reasons people get in touch are modern sealant on a period surround and draughts and rain around sash boxes.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. The mastic around them dries out and cracks with age, letting in draughts and water.
There’s a 12-month guarantee on every job, large or small.
- Place
- Millbank (SW1P, W1J, SW1V)
- Wider area
- Greater London
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What happens if it’s left?
New sash windows are a major, costly change, and in listed buildings it may need consent. If the frames are sound, renewing the mastic deals with gaps and draughts at the surround. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Millbank, the repair is bigger than a sealant job.
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote and we will talk you through it.
Why us?
- Sanitary silicone with an anti-fungal additive in wet areas
- Old sealant always removed completely
- Quality sealants from Arbo and Everbuild
- Full insurance on every job
Towns and villages near Millbank
More services for Millbank
What we’re called out for in Millbank
Sand mastic slowly weathers. It dries out, cracks and loses its grip on the stone or timber.
People usually contact us when they notice one of these:
- Mastic that needs renewing before redecorating
- Wind and rain getting in round a sash window
- Silicone on a period window that looks wrong
- Open joints round the window box
If you let a flat or house near London Victoria station, older sash windows in a rental need their mastic kept sound to keep the weather out.
What your quote should include
- What the quote includes, VAT included or not
- Who does the work, and how experienced they are
- What product goes in the joint
- What happens if they find a problem under the old sealant
Surface by surface
Period and listed homes
On a listed home or in a conservation area, the right material matters. Sand mastic is often the preferred finish.
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We work on single windows or whole elevations.
Should I try it myself first?
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
If you’re set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Aftercare tips
Once the sealant has cured, a few habits help it last:
- Make sure water runs off the sill
- Renew mastic before redecorating the windows
- Find out about consent before window work on a listed home
- Keep modern sealant off the mastic
Leave the new mastic alone while it firms up. It skins over quickly but needs longer to fully harden.
Once mastic starts to crumble, rain gets in. That water can reach the timber frame and the wall, so renewing it early is worth it.
What sealant work can’t fix
Some problems need a builder, plumber or other trade rather than us:
- Masonry that needs repairing
- Sash cords, weights and draught-proofing of the sashes
- Cracked or broken glass
If you’re not sure, just call 0345 464 0079 or send us an email and we’ll give you a straight answer before booking.
Joints and surfaces we work on
- Brick reveals
- Tenement windows
- Stone surrounds
- Sash and case windows
- Period & listed homes
- Timber door frames
Millbank homes and the weather
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Schools such as Harris Westminster Sixth Form are buildings too, and its window and door frames need their mastic kept sound, just like a home’s. Millbank is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Millbank is about 1 mile south-east of City of Westminster, in Greater London. Every kind of property in Millbank is covered for sand mastic, old or new, large or small. Every job comes with our one-year guarantee. We cover 764 towns and villages across Greater London.
We cover every part of the SW1P, W1J and SW1V postcode area for sand mastic and the streets around it. If you need sand mastic at a property on Eaton Lane, Wilton Road and Castle Lane or a nearby road, our applicators can take on the job. Millbank is on the A4 and A202, which makes it straightforward to reach. Nearby, we also carry out sand mastic in Westminster (1 mile north), Victoria (1 mile south-west), Pimlico (1 mile south), Vauxhall (1 mile south-east) and Lambeth (1 mile south-east). Within a short drive, we also cover Kensington (3 miles west), Shoreditch (3 miles north-east), Walthamstow (8 miles north-east), Hoxton (3 miles north-east), Whitechapel (3 miles north-east) and Hampstead (4 miles north-west).
Local landmarks in Millbank
Around Millbank, our work takes us to homes and buildings near Blewcoat School, St Matthew's School and London Library and the streets around them. Nearby too are St James's Park (under half a mile north) and Grafton Arms (less than half a mile south). For rail, the closest station is London Victoria station, roughly 0.6 miles south-west. A little further out are Westminster Hospital (under half a mile east) and Kingly Court (0.9 miles north). Open spaces near Millbank include St. James's Park Lake and Ludgate Hill.
Your questions about sand mastic in Millbank
Do you work for landlords with property near London Victoria station?
Yes, rental work is part of what we do. You can call 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before any work starts.
Is parking a problem for a job in Millbank?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Can you quote for more than one area?
Of course. Doing several areas at once is normally more efficient, so mention them when you ask for a quote.
Do you hold any approvals?
Yes. Mr Mastic is an ARBOMaster approved applicator.
Where are you based?
Our base is in Crawley, and we work across South East England, London and Scotland.
Can old silicone round a sash window be swapped for sand mastic?
Often, yes. Once the silicone is out and the joint prepared we point it with sand mastic.
Do I have to be there?
We need access to the joints, so we will agree that with you when we book. Indoors, that usually means someone at home.
Can you seal over the old sealant?
No, and we never do. It may look fine at first, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
How it works
On the day, there’s very little for you to do. Point us to the joints and we’ll get on with it. The work itself takes a few hours for a single window, longer for several, including the tidy-up. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- 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.
- The surface is finished to suit the stone or brick.
Preparing for the visit
- Clear the area around the work
- Tell us about access, such as stairs, a lift or high-level joints
- Mention if the joints have been sealed before
Getting a quote
If you’re in Millbank and need sand mastic, ring 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you’ll get a clear quote before work begins.