Greater London · England
Sand mastic for sash & case windows in St Giles, Greater London
Sand mastic across St Giles and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- A silicone bead on a sash window that spoils the look
- Tired mastic found when preparing windows for paint
- Mastic dropping out of the joint
When something else is needed
Before you book, it’s worth knowing the limits too:
- Rotten sashes, sills or window boxes (a joiner’s job)
- Cracked or broken glass
- Whether work needs listed building consent
If in doubt, phone 0345 464 0079 or send us an email and we will say what we think before booking.
Joints and surfaces we work on
- Period & listed homes
- Brick reveals
- Sash and case windows
- Tenement windows
- Stone surrounds
- Timber door frames
Sand mastic for homes and businesses in St Giles
Old sand mastic cracks, crumbles and falls out over time, leaving gaps round the window. We rake it out and renew it and tidies the surround. We are often asked to deal with patchy fillers round a sash window and a silicone bead on a sash window that spoils the look, on period & listed homes, stone surrounds and tenement windows.
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.
You get a 12-month guarantee, the same in St Giles as everywhere else we work.
- Location
- St Giles (W1F, W1D, W1T)
- Region
- Greater London
- Cover
- A year, on every job
- Quote
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What affects the cost of sand mastic
Call for a quick quote. What matters most is:
- Access and height
- Working hours on commercial sites
- The size of the job
- Any mould that needs treating
We don’t show prices on the website, because each job is priced on what it involves. For a quick quote, please ring 0345 464 0079 or send us an email and we’ll talk you through it.
Asking for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- The problem you’ve noticed
- Where the property is
- How many joints, rooms or windows are involved
- Any previous sealing or DIY work
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email pictures if that is easy.
Common problems we fix in St Giles
Paint, silicone or cement used over old mastic causes problems. They do not move with the timber, and they generally need raking out.
The most common problems we see are:
- Window mastic to renew ahead of painting
- Draughts and rain around sash boxes
- Gaps round a timber door in stone or brick
- Mastic dropping out of the joint
For landlords with property near Tottenham Court Road station, any sash windows need sound mastic to keep draughts and rain out.
Before booking anyone
- How the joint is cleaned and prepared
- Is VAT in the price?
- Which sealant they’ll use, and why
- When the joint can take water or movement
Why act early in St Giles
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 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 failed joint rarely gets cheaper to fix by waiting. If you are not sure whether it needs doing, ring 0345 464 0079 or email us and we will give you an honest view and a quote.
Why St Giles customers choose us
- 4.9 on Google from 180+ five-star reviews
- An ARBOMaster approved applicator
- 20+ years of sealant experience
- Arbo and Everbuild products
Read what affects the cost and customer reviews.
Nearby places to St Giles
What else we do in St Giles
Landlords, agents and businesses in St Giles
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together, and we’re fully insured for the work.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Your questions about sand mastic in St Giles
Is St Giles in your area for sand mastic?
Yes, St Giles is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or send us an email and let us know what needs doing, and we’ll give you a clear quote.
I let a flat near Tottenham Court Road station. Can you help?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear quote.
Is it worth trying it myself?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. If it does not work out, we can redo it.
Can you work on commercial sites?
Yes. Hotels, offices and other businesses use us.
Can I paint the new mastic?
The usual advice is to leave sand mastic unpainted. If you are redecorating the window, ask us first and we’ll advise.
Can old silicone round a sash window be swapped for sand mastic?
Normally, yes. Once the silicone is out and the joint prepared, sand mastic is applied by hand.
Can new sealant go over the old?
No. Fresh sealant does not stick to old sealant, and anything trapped underneath, including mould and water, stays there. We remove it all first.
Will there be a smell?
There can be a smell while the sealant cures, but it fades. Ventilation helps.
Aftercare tips
How long the joints last depends on use and care. Here’s what we suggest:
- Plan mastic work ahead of painting
- Ask a joiner to look at soft timber first
- Look over the window mastic once a year
- Avoid heavy scraping on the mastic joint
Do not run silicone over the new mastic. If anything cracks, get it looked at before trying a quick fix.
Fine cracks show the mastic is starting to fail. It’s easier to renew it before it drops out.
St Giles homes and the weather
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. Historic houses like Benjamin Franklin House (about 0.5 miles south) are a reminder that the area around St Giles has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
If you live in an older home near Soho Baptist Chapel, the joint between an old wall and a newer frame is generally the first place rain gets in. As a London address, St Giles can be tricky for parking: let us know about parking bays, permits or a driveway.
St Giles is about 1 mile east of City of Westminster, in Greater London. Whether you’re in the middle of St Giles or further out, sand mastic is available for homes and businesses alike. Our area takes in 764 places across Greater London, large and small.
Every address in W1F, W1D and W1T is within our area for sand mastic. If you need sand mastic at a property on Duck Lane, Drury Lane and Bridle Lane or a nearby road, we can help. With the A301 and A400 close by, St Giles is easy for our applicators to reach for sand mastic. Close by, we work in Seven Dials (1 mile south), West End (1 mile south-west), Soho (1 mile south-west), Covent Garden (1 mile south-east) and Chinatown (1 mile south-west). We also work in nearby towns such as 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).
Landmarks near St Giles
In St Giles, that means homes and buildings near LSE Shaw Library, The Crown pub and Mercers' School. Also close by are London Nautical School (1 mile south-east) and St Anne's Churchyard (under half a mile south-west). There’s a railway station in St Giles itself: Tottenham Court Road station. Well-known places in the area include Montfichet's Tower (1.1 miles east) and Kingly Court (0.5 miles west). For a walk, there’s Barnsbury Wood and Ludgate Hill.
How it works
You don’t need to clear the whole room or building before we come, just the space around the work. Everything nearby is protected, and the job takes a few hours for a single window, longer for several in most cases. In a London area like St Giles, the main things to plan are parking and access: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- We look at the surrounds with you and agree the joints to renew.
- Old mastic and any loose material are raked out.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- The surface is finished to suit the stone or brick.
Getting ready for the visit
- Keep pets and children clear of the area while we work
- Clear items away from the joints we are working on
- For indoor joints, keep the area dry beforehand if you can
Getting a quote
Need a quote? Please call 0345 464 0079 or email us and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.