Greater London · England
Sand mastic for sash & case windows in St Margarets, Greater London
Our applicators work in St Margarets on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly.
- Cracked mastic round a front door frame
- Gaps between timber frames and stone or brick
- Mastic that needs renewing before redecorating
Common problems we fix in St Margarets
Rain on the window surround works into any crack and pushes it out. Exposed elevations generally fail first.
People generally contact us when they notice one of these:
- Silicone on a period window that looks wrong
- Weathered mastic on the most exposed windows
- Window mastic to renew ahead of painting
- Mastic round period door frames that has failed
Richmond House, about 1 mile south, is one of the historic houses in the wider area around St Margarets, and older homes nearby need a sealant that suits their walls.
What your quote should include
- Who does the work, and how experienced they are
- The length of the guarantee
- What the quote includes, VAT included or not
- Is the old sealant removed completely?
Sand mastic for homes and businesses in St Margarets
For a listed home or one in a conservation area, ask your local planning authority if consent is needed before window work. Sand mastic is often favoured as a like-for-like material. We work on period & listed homes, stone surrounds and tenement windows, and people most often call us about cracked mastic round a front door frame and cement or filler used on old window joints that has cracked.
London has a lot of flats and conversions, where windows are often on upper floors. In a converted house or block, the lease usually says who is responsible for the windows, so it’s worth checking before booking, and access in St Margarets is something to talk through when you book.
All our work comes with our 12-month guarantee, wherever you are in Greater London.
- Place
- St Margarets (TW1, TW7, TW9)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Work for landlords, hotels and businesses
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Mouldy or split sealant often shows up at the end of a tenancy. Several properties can go on one quote.
DIY sealant or a professional job?
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
If you’ve already had a go yourself, that is fine. We cut it out and start again.
What happens on the day
Every visit runs the same way: we check the joints, mask and protect the surrounding surfaces, carry out the job and tidy away. Most jobs take a few hours for a single window, longer for several. For a job in St Margarets, 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.
- We check the window surrounds and agree which joints need renewing.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic is not too thick.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- The mastic is finished to sit tidily against the stone or brick.
Getting ready for the visit
- Tell us about any water getting in
- Let us know about stairs, lifts or work at height
- Try not to wet indoor joints just before the visit
Get a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. When it suits you, ring 0345 464 0079 or email us.
Advice
Quotes for sand mastic in St Margarets
Your quote is based on your job. We look at:
- How many rooms, windows or areas are involved
- The type of sealant required
- The number and length of the joints
- Working hours on commercial sites
Commercial jobs are quoted on the same basis as homes: how much there is to do, how we reach it and what it needs, along with when we can work on site. Ask us for a quote and we will explain what it covers.
What to tell us for a quote
Photos help, but a description is a good start. Please mention:
- Any previous sealing or DIY work
- How we’d reach the joints
- What the problem is, such as mould, gaps, leaks or cracking
- A few pictures by email, if you can
For sand mastic in St Margarets, ring 0345 464 0079 or drop us an email. Tell us what the problem is and where, and we will agree the price before any work begins.
St Margarets: your questions answered
Do you work for landlords with property near St Margarets (London) station?
Yes. We work for landlords and agents as well as householders, and several properties can go on one quote. Just call 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll send you a clear quote.
Can you do sand mastic in St Margarets?
Yes. Our work covers London and the South East, and St Margarets is part of that. Just call 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear price.
What is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.
How long does the job take?
It depends on the size of the job, but as a guide it takes anything from a few hours to a full day, depending on how many windows. We’ll give you a better idea when we quote.
Can new sealant go over the old?
No. Fresh sealant doesn’t stick to old sealant, and it traps any mould or water underneath. It all has to come out first.
Are you ARBOMaster approved?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
What do you put in the joint?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Can you work on commercial sites?
Yes. We can plan bigger jobs in stages.
Why it’s worth doing now in St Margarets
An open joint round the frame lets weather in. Water can get to the frame and the masonry, so dealing with it now protects both. Damp from a failed joint spreads quietly in older London brickwork and timber, and by the time it shows on a wall or ceiling in St Margarets, the repair is bigger than the sealant job would have been.
The cost depends on the size of the job, how much old material has to come out and access to the work. We give a clear quote before any work starts, so you know where you stand.
Why St Margarets clients choose us
- Old sealant always removed completely
- Anti-fungal sanitary silicone in wet areas
- A 12-month guarantee on all work
- Full insurance on every job
Take a look at what affects the cost or customer reviews.
What sand mastic looks like in St Margarets
The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Richmond House (about 1 mile south) are a reminder that the area around St Margarets 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.
If you look after a building such as Worple Primary School, its window and door frames need their mastic kept sound, just like a home’s. Rented homes near St Margarets (London) station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
St Margarets is about 1 mile north-east of Twickenham, in Greater London. Every kind of property in St Margarets can book us for sand mastic, old or new, large or small. The work is guaranteed for a year. Our Greater London coverage runs to 764 places, St Margarets among them. We also work in London, about 10 miles from St Margarets.
Postcode districts we cover here for sand mastic: TW1, TW7 and TW9. We cover properties on Eve Road, Park Road and Crown Road and the roads around them. Being close to the A316 and A3004, St Margarets is simple for us to get to. We also cover the places around St Margarets: Isleworth (1 mile north-west), Richmond (1 mile east), Ivybridge (1 mile west), Eel Pie Island (1 mile south) and Twickenham (1 mile south-west). Within a short drive, we also cover London (10 miles east), City of Westminster (8 miles north-east), Marylebone (8 miles north-east), Kensington (6 miles north-east), St Pancras (10 miles north-east) and Shoreditch (11 miles north-east).
Near you in St Margarets
In St Margarets, that means homes and buildings near Richmond Green, Orleans Park School and The Turks Head pub and the streets around them. St Margarets has its own railway station: St Margarets (London) station. Other landmarks nearby include South Middlesex Hospital (0.8 miles west) and Eel Pie Island Museum (0.8 miles south). The countryside around St Margarets includes Richmond Hill and Ham Lands.
Places near St Margarets
What else we do in St Margarets
What we can’t put right
In fairness, some problems need a different trade:
- Decayed frames that need repair
- Sashes that need overhauling
- Putty and glazing repairs
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think before booking.
Where we work in St Margarets
- Tenement windows
- Sash and case windows
- Brick reveals
- Stone surrounds
- Period & listed homes
- Timber door frames