Greater London · England
Sand mastic for sash & case windows in Seven Dials, Greater London
We cover Seven Dials for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly.
- A silicone bead on a sash window that spoils the look
- Open joints round the window box
- Cement or filler used on old window joints that has cracked
How we quote for sand mastic
You’ll get a clear quote before work begins. It takes into account:
- The number of rooms or windows
- Mould in or behind the old joints
- The type of sealant required
- Working hours on commercial sites
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 we need extra access for height. Your quote takes all of that into account.
Helping us quote
When you call or email, these details help:
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it has been sealed before
- Roughly how big the job is
- The address or postcode of the job
It all starts with a short chat. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. When it suits you, call 0345 464 0079 or email us.
Sand mastic in Seven Dials, done properly
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditional guidance is not to paint over it, so ask us before you decorate. If you’re dealing with mastic round period door frames that has failed and silicone on a period window that looks wrong, we can put it right, on tenement windows, sash and case windows and brick reveals alike.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in, in Seven Dials as anywhere.
Our work is backed for twelve months, in Seven Dials and everywhere else we cover.
- Location
- Seven Dials (W1F, W1D, W1T)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Towns and villages near Seven Dials
Other services in Seven Dials
What sand mastic looks like in Seven Dials
With historic houses such as Benjamin Franklin House (about 0.4 miles south) nearby, there’s older building stock in the area around Seven Dials as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For an older house near a landmark such as Soho Baptist Chapel, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Letting a property close to Tottenham Court Road station? Then older sash windows in a rental need their mastic kept sound to keep the weather out.
Seven Dials is about 1 mile east of City of Westminster, in Greater London. Seven Dials gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Across Greater London, we cover 764 places, Seven Dials among them.
Jobs for sand mastic in W1F, W1D and W1T works the same way as everywhere else we cover. Streets in the area include Duck Lane, Drury Lane and Bridle Lane, and we cover them all. Seven Dials sits on or near the A301 and A400, so getting to you is simple. Other places close to Seven Dials include St Giles (1 mile north), West End (1 mile west), Soho (1 mile west), Covent Garden (1 mile east) and Chinatown (1 mile south-west). Further out, we also cover Kensington (3 miles west), Walthamstow (7 miles north-east), Hampstead (4 miles north-west), Ruislip (13 miles west), Stockwell (3 miles south) and Orpington (13 miles south-east).
Near you in Seven Dials
Typical jobs here are in homes near London Nautical School, St Anne's Churchyard and LSE Shaw Library, among other places. Other local landmarks include Two Brewers pub (within half a mile south-west) and Mercers' School (0.8 miles east). Seven Dials has its own railway station: Tottenham Court Road station. Other landmarks nearby include Kingly Court (0.5 miles west) and St Paul's Hospital (under half a mile north-east). For a walk, there’s Barnsbury Wood and Ludgate Hill.
Aftercare tips
No joint lasts for ever, but care makes a real difference. Our tips:
- Look over the window mastic once a year
- Plan mastic work ahead of painting
- Ask a joiner to look at soft timber first
- Check with your local planning authority if your home is listed
When preparing windows for paint, take care around the mastic. It can be damaged by heavy scraping.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
When to call us in Seven Dials
Age is the main cause. Even well-laid mastic needs renewing in time, depending on exposure and upkeep.
Most people get in touch when they notice one of these:
- Weathered mastic on the most exposed windows
- Wind and rain getting in round a sash window
- Cement or filler used on old window joints that has cracked
- Mastic that needs renewing before redecorating
Managing a site like St Josephs Catholic Primary School? Then the mastic around its windows and doors needs looking after like any other building’s.
What to look for in a quote
- Whether VAT is included
- Who does the work, and how experienced they are
- Is the old sealant removed completely?
- How long the guarantee is
Why act early in Seven Dials
Draughts round a sash window are not always the sashes. Open mastic joints round the box can let air in, and renewing the mastic closes them. 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.
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all play a part.
Why Seven Dials clients choose us
- A 12-month guarantee on all work
- An ARBOMaster approved applicator
- Sanitary silicone with an anti-fungal additive in wet areas
- Neat joints and a tidy finish
See our cost guide and customer reviews.
For landlords and businesses
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
If you manage several properties in or around Seven Dials, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
Your questions about sand mastic in Seven Dials
Do you cover Seven Dials for sand mastic?
Yes, Seven Dials is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or email us and tell us what needs doing.
Do you work for landlords with property near Tottenham Court Road station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just ring 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear quote.
Can you work on commercial sites?
Yes. We have worked for hotels, offices and other businesses.
What sealant do you use?
Products from Arbo and Everbuild, among others, chosen to suit the joint. We explain the product when we quote.
Do you hold any approvals?
Yes. We’re an ARBOMaster approved applicator, the approved applicator scheme for Arbo sealants.
How long will you be here?
Most jobs take a few hours for a single window, longer for several, including the preparation. Your quote will say how long we expect yours to take.
Does someone need to be in?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
Will the old sealant be removed?
Always. Sealing over old sealant is the main reason resealing fails early, so we never do it.
What happens on the day
All our tools and materials come with us in the van, so there’s nothing for you to buy. Once we’ve agreed what’s being done, we protect the area and start. It normally takes a few hours for a single window, longer for several. In a London area like Seven Dials, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we are 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.
- The surface is finished to suit the stone or brick.
Preparing for the visit
- Let us know about stairs, lifts or work at height
- Clear the area around the work
- For indoor joints, keep the area dry beforehand if you can
Ask for a quote
Asking for a quote is easy: let us know the job and the location and its rough size. Photos by email help us understand the job.