Greater London · England
Upper Walthamstow Sand Mastic
Our applicators work in Upper Walthamstow on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly and a 12-month guarantee.
- Mastic dropping out of the joint
- Cement or filler used on old window joints that has cracked
- Open joints round the window box
What we’re called out for in Upper Walthamstow
Timber swells and shrinks with the weather. That movement opens up the mastic joint little by little.
Keep an eye out for these signs:
- Gaps between timber frames and stone or brick
- Wind and rain getting in round a sash window
- Mastic round period door frames that has failed
- Weathered mastic on the most exposed windows
Upper Walthamstow is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Comparing quotes
- Whether the sealant suits the joint
- What insurance they hold
- What preparation is included
- Is the old sealant removed completely?
Sand mastic in Upper Walthamstow
We renew sand mastic around sash windows and doors in stone and brick. The old mastic is raked out, the joint is prepared and new mastic is shaped by hand. If you have old sand mastic that has cracked, crumbled or fallen out and modern sealant on a period surround, we can help.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Place
- Upper Walthamstow (E17, E18, E10)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Places near Upper Walthamstow
What else we do in Upper Walthamstow
Frames and glazing around Upper Walthamstow
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. With historic houses such as Valentines Mansion (about 2.9 miles east) nearby, there’s older building stock in the area around Upper Walthamstow as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
Homes close to Church of St Peter in the Forest include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame. If you look after a building such as The Woodside Primary Academy, its window and door frames need their mastic kept sound, just like a home’s.
Upper Walthamstow is about 1 mile east of Walthamstow, in Greater London. We provide sand mastic to homes and businesses in Upper Walthamstow and the surrounding area, as part of our work across Greater London. Upper Walthamstow is one of 764 towns and villages in Greater London we cover for sand mastic. For nearby work, see our London page (7 miles or so).
Here we cover the E17, E18 and E10 postcode area for sand mastic. You’ll find streets such as Elm Road, Avon Road and Church Lane. Close by, we work in Snaresbrook (1 mile east), Walthamstow Village (1 mile west), Bakers Arms (1 mile south-west), South Woodford (1 mile north-east) and Walthamstow (1 mile west). Larger places within reach include London (7 miles south-west), City of Westminster (8 miles south-west), Marylebone (8 miles south-west), Kensington (11 miles south-west), St Pancras (7 miles south-west) and Shoreditch (5 miles south-west).
Around Upper Walthamstow
Locally, jobs take us to homes and businesses close to The Flower Pot pub, Holy Family Catholic School and Warwick School for Boys, among other places. There’s a railway station in Upper Walthamstow itself: Wood Street station. A little further out are 17 & Central (1.1 miles west) and Wanstead Hospital (1.1 miles east). For a walk, there’s Ainslie Wood and Hollow Pond.
What happens on the day
When we get to you, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take anything from a few hours to a full day, depending on how many windows. In a London area like Upper Walthamstow, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- Large voids are packed out.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
How to prepare
- Try not to wet indoor joints just before the visit
- For business premises, tell us about site rules or sign-in
- Tell us about any water getting in
Get a quote
Asking for a quote is easy: let us know what needs doing and where. Photos by email help us understand the job.
Read more
What affects the cost of sand mastic
There’s no set price list, because no two jobs are the same. The quote depends on:
- Whether old sealant or filler has to be cut out
- Whether there’s mould to deal with
- How easy the joints are to reach
- How much there is to do
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Asking for a quote
Photos help, but a description is a good start. Try to tell us:
- Where the job is, and your postcode
- What the problem is, such as mould, gaps, leaks or cracking
- Any access issues, like height or stairs
- Whether it has been sealed before
For sand mastic in Upper Walthamstow, phone 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you’ll get a clear quote before work begins.
Honest limits
New sealant can’t fix everything, and we’d rather say so up front. Sealant will not put right:
- Rotten sashes, sills or window boxes (a joiner’s job)
- Crumbling stone or brickwork round the window
- Putty and glazing repairs
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we will tell you honestly before booking.
Where we work in Upper Walthamstow
- Stone surrounds
- Brick reveals
- Tenement windows
- Sash and case windows
- Period & listed homes
- Timber door frames
Why act early in Upper Walthamstow
New sash windows are a major, costly change and on a listed home, consent may be needed. 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 by the time it shows on a wall or ceiling in Upper Walthamstow, the repair is bigger than the sealant job would have been.
The cost depends on the amount of work, 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 book with us
- Anti-fungal sanitary silicone in wet areas
- 4.9 on Google from 180+ five-star reviews
- One-year guarantee on every job
- Neat joints and a tidy finish
Take a look at what affects the cost and customer reviews.
Landlords, agents and businesses in Upper Walthamstow
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
We also work for property managers and facilities teams. Several sites can go on one quote, and we are fully insured.
FAQs for Upper Walthamstow
Is parking an issue for sand mastic in Upper Walthamstow?
Parking in Upper Walthamstow, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Do you cover Upper Walthamstow for sand mastic?
Yes. Our work covers London and the South East, and Upper Walthamstow is part of that. 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 price.
Should I try DIY first?
Sometimes. 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.
What do you need from me for a quote?
Just the basics: where it is, what you’ve noticed and how we reach it. Then ring 0345 464 0079 or drop us an email.
Where is Mr Mastic based?
We work from Crawley. We cover Upper Walthamstow and the rest of Greater London.
Can I choose the sealant colour?
In most cases you can choose. We’ll explain which colours are available.
Is there any odour?
That depends on the sealant. Some smell for a while, some hardly at all.
Is it possible to paint over sand mastic?
The usual advice is to leave sand mastic unpainted. If you’re redecorating the window, ask us first and we will advise.
How to look after the new joints
Looking after new joints is easy:
- Do not paint over the new mastic
- Check the mastic when you check the paintwork
- Renew mastic before redecorating the windows
- Avoid heavy scraping on the mastic joint
Look at the mastic when you look over the windows. Catching cracks early keeps repairs small.
Small cracks are a sign the mastic is ageing. Renewing it then is simpler than waiting until it falls out.