Greater London · England
Sand mastic for sash & case windows in Mildmay, Greater London
Professional sand mastic in and around Mildmay, with old sealant always removed completely and a 12-month guarantee.
- Mastic round period door frames that has failed
- Gaps where the frame meets the masonry
- Tired mastic found when preparing windows for paint
Mildmay questions
Can you do sand mastic in Mildmay?
Yes, Mildmay is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or drop us an email and let us know what needs doing, and we’ll give you a clear price.
Can parking be tricky for a visit in Mildmay?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly.
What guarantee comes with the work?
You get our one-year guarantee on every job.
Where is Mr Mastic based?
We’re based in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
What’s sand mastic made of?
Sand plus a binder based on linseed oil. It’s applied by hand and shaped to suit the surround.
How long will you be here?
As a guide, most jobs take anything from a few hours to a full day, depending on how many windows. Bigger jobs take longer.
Is there any odour?
That depends on the sealant. Some products have a noticeable smell, others very little, and any smell fades as they cure.
Do you have insurance?
Yes. We are fully insured for domestic and commercial work.
How we handle sand mastic in Mildmay
Sand mastic is the traditional way to point the gap between a timber window frame and the stone or brick around it. It’s made from sand and a linseed-oil-based binder, applied by hand. On older homes, it suits the building far better than silicone. Common call-outs are for mastic round period door frames that has failed and modern sealant on a period surround, across tenement windows, stone surrounds and period & listed homes.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first.
You are covered for a year from the day we finish. If anything is not right with it, call 0345 464 0079 or send us an email.
- Location
- Mildmay (N1, N16, E8)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Other services in Mildmay
What we’re called out for in Mildmay
Most of it is simply age. Sand mastic is a maintenance item like any pointing, depending on exposure and upkeep.
Signs it’s time to call us include:
- Mastic round period door frames that has failed
- A silicone bead on a sash window that spoils the look
- Failed mastic on an exposed elevation
- Old sand mastic that has cracked, crumbled or fallen out
If you live in an older home near Church of St Jude and St Paul, the joint between an old wall and a newer frame is usually the first place rain gets in.
Comparing quotes
- Is the old sealant removed completely?
- What the quote includes, VAT included or not
- Whether you can choose the colour
- What product goes in the joint
Aftercare tips
A little care helps the new joints last. We recommend:
- Plan mastic work ahead of painting
- Don’t paint over the new mastic
- Avoid heavy scraping on the mastic joint
- Have rotten timber repaired before new mastic goes in
Avoid sealing over the mastic with silicone. If anything cracks, get it looked at before trying a quick fix.
Gaps round a sash box let in draughts and rain. The longer it’s left, the more the joint opens as more mastic falls out.
Landlord and commercial work in Mildmay
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
How we quote for sand mastic
You will get a clear quote before any work starts. It’s based on:
- The type of sealant required
- The number and length of the joints
- The old material and how stubborn it is
- Any mould that needs treating
What you pay reflects the work, not a rough estimate. That’s why we ask a few questions first and agree the price before starting.
What to tell us for a quote
Photos by email are helpful but not essential. Try to tell us:
- Access, such as stairs, a lift or height
- Where the job is, and your postcode
- The problem you’ve noticed
- The type of property
If you’re in Mildmay and need sand mastic, call 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.
What happens on the day
When we arrive, we start by going over the job with you, so there are no surprises. Surfaces next to the work are protected before work begins. Most jobs take a few hours per window, depending on the condition of the joints. In a London area like Mildmay, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- 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.
Preparing for the visit
- Let us know about parking restrictions
- Where the joints are inside, avoid wetting them before we arrive
- Let us know if you’ve seen damp or leaks
Get a quote
Need a quote? Please ring 0345 464 0079 or email us with a few details. We’ll explain what we’d do and give you a clear price before any work starts.
Advice
What the job involves on each surface
Tenement and terrace windows
Tenements and terraces often have many sash windows with ageing mastic. We can do one window or several.
Stone surrounds
We take care not to mark the stone while raking out the old mastic.
Frames and glazing around Mildmay
With historic houses such as Sutton House (about 1.4 miles east) nearby, there’s older building stock in the area around Mildmay 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. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
If you look after a building such as Newington Green Primary School, larger buildings have plenty of frames, and the mastic around each one ages. If you let a flat or house near Dalston Kingsland station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Mildmay is about 1 mile north of Hoxton, in Greater London. Anywhere in N1, we cover sand mastic for homes and businesses. Mildmay is one of 764 towns and villages in Greater London we cover for sand mastic.
Our applicators cover all of the N1, N16 and E8 postcode area for sand mastic. Streets in the area include Dove Road, Essex Road and Burma Road. Mildmay is on the A1199, so it’s easy for us to get to with everything needed for sand mastic. We also cover the places around Mildmay: Newington Green (1 mile north), De Beauvoir Town (1 mile south), Canonbury (1 mile south-west), Kingsland (1 mile south-east) and Highbury (1 mile west). Larger places within reach include London (3 miles south), City of Westminster (4 miles south-west), Marylebone (3 miles south-west), Kensington (6 miles south-west), Walthamstow (4 miles north-east) and Hampstead (4 miles west).
Landmarks near Mildmay
Locally, jobs take us to homes and businesses close to City of London Academy Highbury Grove, Highbury Fields and Army and Navy pub and the streets around them. There’s a railway station in Mildmay itself: Dalston Kingsland station. Nearby you’ll also find Clowns Gallery-Museum (0.6 miles south-east) and Hackney Walk (1.5 miles east). The countryside around Mildmay includes Gillespie Park and Ludgate Hill.
Honest limits
New sealant cannot fix everything, and we’d rather say so up front. It won’t solve:
- Putty and glazing repairs
- Crumbling stone or brickwork round the window
- Planning or listed building consent (your local planning authority decides)
If you’re not sure, just call 0345 464 0079 or email us and we’ll give you a straight answer before you book.
Surfaces we seal
- Timber door frames
- Stone surrounds
- Tenement windows
- Sash and case windows
- Brick reveals
- Period & listed homes