Greater London · England
Sand Mastic in Covent Garden
Sand mastic in Covent Garden from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Cement or filler used on old window joints that has cracked
- A silicone bead on a sash window that spoils the look
- Open joints round the window box
The process
On the day, we look over the joints with you first, so there are no surprises. We protect the surfaces around the joints before any work begins. Most jobs take anything from a few hours to a full day, depending on how many windows. In Covent Garden, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- Each surround is checked first.
- The joint is raked out and cleaned.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
Preparing for the visit
- Mention any tricky access
- Mention any sign-in or site rules at work premises
- Try not to wet indoor joints just before the visit
Getting a quote
Asking for a quote is easy: tell us what needs doing and where. A few photos by email make the job easier to understand.
Related advice
Sand mastic in Covent Garden, done properly
Across Covent Garden, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand for a neat, traditional finish. If you have silicone on a period window that looks wrong and gaps between timber frames and stone or brick, we can help, whatever the surface.
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, which is when draughts and damp patches appear in homes in Covent Garden.
Our work is backed for twelve months, in Covent Garden and everywhere else we cover.
- Place
- Covent Garden (W1F, W1D, W1T)
- Wider area
- Greater London
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Work for landlords, hotels and businesses
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we’ll give you a quote.
Nearby places to Covent Garden
Other services in Covent Garden
FAQs for Covent Garden
Can you help a landlord with a rental near London Charing Cross station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just call 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear quote.
Do you cover Covent Garden for sand mastic?
Yes, Covent Garden is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or email us and let us know what needs doing.
Can you replace silicone on a period window with sand mastic?
In most cases. We remove the silicone and clean the joint, then point it with sand mastic.
Do you offer different sealant colours?
In most cases you can choose. We’ll explain which colours are available and agree one before any work starts.
What’s sand mastic made of?
It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.
What sealant do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We’ll tell you what we are using and why.
Is consent needed for window work on a listed home?
Speak to your local planning authority before work starts. Sand mastic is often favoured as like for like but the decision is theirs.
Is it possible to paint over sand mastic?
Traditional guidance is not to paint over sand mastic. If you’re redecorating the window, ask us first and we will talk you through it.
Why act early in Covent Garden
Silicone might seem the quicker option, but it can look wrong on a period surround. Sand mastic is the traditional material and finishes neatly against the masonry. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Covent Garden, the repair is bigger than a sealant job.
Doing several joints on one visit is generally more efficient than separate visits. We’ll give you a clear price for the lot.
Why book with us
- Quality sealants from Arbo and Everbuild
- Fully insured
- Homes, businesses and hotels
- Old sealant always removed completely
Take a look at how sealant jobs are priced or customer reviews.
Covent Garden homes and the weather
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Benjamin Franklin House (about 0.4 miles south) are a reminder that the area around Covent Garden has older buildings as well as new. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
As a London address, Covent Garden can be tricky for parking: let us know about parking bays, permits or a driveway. Homes close to Crown Court Church include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Covent Garden is about 1 mile east of City of Westminster, in Greater London. Our applicators cover sand mastic for homes and businesses in Covent Garden, as part of our work across Greater London. 764 places in Greater London are on our list, from the larger towns to small villages.
Every address in W1F, W1D and W1T is covered for sand mastic, from the main roads to the quietest streets. Streets in the area include Duck Lane, Drury Lane and New Square, and we cover them all. Being close to the A301 and A400, Covent Garden is easy for our applicators to reach for sand mastic. We also cover the places around Covent Garden: Seven Dials (1 mile west), Aldwych (1 mile east), Adelphi (1 mile south), St Giles (1 mile north-west) and Clare Market (1 mile north-east). Further out, we also cover Kensington (4 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).
What’s near Covent Garden
We work in homes and buildings around Victoria Embankment Gardens, London Nautical School and Mercers' School. Also close by are Punch & Judy pub (under half a mile south-west) and LSE Shaw Library (within half a mile north-east). There’s a railway station in Covent Garden itself: London Charing Cross station. Other landmarks nearby include Montfichet's Tower (0.9 miles east) and Savoy Hospital (within half a mile south-east). Not far away are Ludgate Hill and Barnsbury Wood.
DIY versus a professional finish
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
Common problems we fix in Covent Garden
Some old mastic was never deep enough. A thin layer doesn’t hold well so we make sure the new mastic is the right thickness.
These are the problems we’re asked about most:
- Crumbling sand mastic round a window
- Cracked mastic round a front door frame
- Weathered mastic on the most exposed windows
- Modern sealant on a period surround
Rented homes near London Charing Cross station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Before you book anyone
- How hidden problems are handled
- Whether all the old sealant comes out first
- What guarantee comes with the work
- Who turns up on the day
Surface by surface
Period and listed homes
Sand mastic is the like-for-like choice for many period homes. On listed buildings, check with your planning authority first.
Sash and case windows
Most of our sand mastic work is on sash windows. Each joint round the box is raked out and renewed.
Keeping the joints in good condition
How long the joints last depends on use and care. Here’s what we suggest:
- Leave the new mastic unpainted
- Get any rot dealt with first
- Don’t run silicone over sand mastic
- Renew mastic before redecorating the windows
Do not run silicone over the new mastic. If anything cracks, get it looked at before trying a quick fix.
Renewing mastic before redecorating saves doing it twice. Paint over cracked mastic only covers it up.