Greater London · England
Sand mastic for sash & case windows in Greenwich, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homes and businesses in Greenwich and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Mastic that needs renewing before redecorating
- Gaps round a timber door in stone or brick
- Old sand mastic that has cracked, crumbled or fallen out
Sand mastic in Greenwich, done properly
Silicone on a period window often looks wrong and is not always the right material. Sand mastic is the traditional choice and we can swap the silicone for it. We work on tenement windows, timber door frames and stone surrounds, and the jobs we see most are failed mastic on an exposed elevation and gaps round a timber door in stone or brick.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. Over the years, the sealant around them shrinks, cracks and pulls away, letting in draughts and water.
A 12-month guarantee comes as standard, so you’re covered after we’ve gone.
- Place
- Greenwich (SE10, SE3, SE8)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Do you need sand mastic in Greenwich?
Paint, silicone or cement used over old mastic causes problems. They do not suit the joint, and they normally need raking out.
The most common problems we see are:
- Window mastic to renew ahead of painting
- Gaps where the frame meets the masonry
- Cement or filler used on old window joints that has cracked
- Wind and rain getting in round a sash window
Greenwich is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
What your quote should include
- What product goes in the joint
- Are they insured?
- What happens if the job turns out different
- Whether all the old sealant comes out first
How it works
We bring everything the job needs with us, so you do not need to buy or prepare anything. After a quick look at the joints together, we protect the area and start. Most jobs take a few hours per window, depending on the condition of the joints. For a job in Greenwich, 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.
- Each surround is checked first.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic is not too thick.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Mention any sign-in or site rules at work premises
- Clear items away from the joints we are working on
Get a quote
We quote each job on its own, so the first step is telling us about yours. Simply phone 0345 464 0079 or send us an email and describe the job.
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What affects the cost of sand mastic
There’s no set price list, because no two jobs are the same. What we look at:
- The number of rooms or windows
- Access and height
- Whether there’s mould to deal with
- How much old sealant there is and how hard it is to remove
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you’re unsure, call 0345 464 0079 or send us an email and we will give you an honest view and a quote.
What to tell us for a quote
Before you ask for a quote, have a think about:
- Access, such as stairs, a lift or height
- Roughly how big the job is
- The address or postcode of the job
- Pictures of the joints, sent by email
Want a quote for sand mastic? Please phone 0345 464 0079 or send us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Looking after it afterwards
Simple care keeps the joints in good condition. Our advice:
- Ask us before painting near the mastic
- Ask a joiner to look at soft timber first
- Avoid patching sand mastic with silicone
- Make sure water runs off the sill
Look at the mastic when you look over the windows. Catching cracks early keeps repairs small.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger.
Different surfaces, different methods
Tenement and terrace windows
Tenements and terraces often have many sash windows with ageing mastic. We can do one window or several.
Brick reveals
Loose mastic comes out and deep gaps are packed before pointing.
Can I do it myself?
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.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
What sand mastic looks like in Greenwich
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
In the older streets around St Mary's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame. Managing a site like Meridian Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Greenwich is about 4 miles east of London, in Greater London. Wherever you are in the SE10 postcode area, we can carry out sand mastic at your property. We cover 764 towns and villages across Greater London, from the larger towns to small villages.
Jobs for sand mastic in SE10, SE3 and SE8 works the same way as everywhere else we cover. If you need sand mastic at a property on Cade Road, Webb Road and Creek Road or a nearby road, we can help. Being close to the A2203 and A2211, Greenwich is easy for our applicators to reach. Neighbouring places we cover for sand mastic include Maze Hill (1 mile north-east), Vanbrugh Park Estate (1 mile east), Blackheath (1 mile south-east), Westcombe Park (1 mile east) and Isle of Dogs (1 mile north-west). Larger places within reach include London (4 miles west), City of Westminster (7 miles west), Marylebone (7 miles west), Kensington (9 miles west), St Pancras (6 miles north-west) and Shoreditch (5 miles north-west).
What’s near Greenwich
Locally, jobs take us to homes and businesses close to The Plume of Feathers pub, John Roan School and Royal School of Naval Architecture and Marine Engineering and the streets around them. Also close by are Island Gardens (0.6 miles north-west) and St. Paul's (1.1 miles west). Greenwich has its own railway station: Maze Hill station. Other landmarks nearby include Greenwich Castle (within half a mile south-west) and Greenwich District Hospital (0.5 miles north-east). Not far away are Tower Hill and Creekside Discovery Centre.
Also near Greenwich
More services for Greenwich
When something else is needed
Sealant isn’t the answer to every problem, and we’d rather say so up front. Sealant won’t put right:
- Putty and glazing repairs
- Rotten sashes, sills or window boxes (a joiner’s job)
- Planning or listed building consent (your local planning authority decides)
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly before you book.
Joints and surfaces we work on
- Tenement windows
- Brick reveals
- Period & listed homes
- Timber door frames
- Stone surrounds
- Sash and case windows
Questions from Greenwich
Is parking a problem for a job in Greenwich?
Parking in Greenwich, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Is Greenwich in your area for sand mastic?
Yes. Our work covers London and the South East, and Greenwich is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear price.
Are you fully insured?
Yes. We’re fully insured.
What should I tell you?
Only a few details: where it is, what you’ve noticed and how we reach it. After that, simply ring 0345 464 0079 or email us.
What’s sand mastic made of?
A traditional pointing material made from sand and a linseed-oil-based binder for the joint between timber frames and masonry.
Can you seal over the old sealant?
No. Fresh sealant doesn’t stick to old sealant, and it traps any mould or water underneath. We remove it all first.
What sealant do you use?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice, and we’ll tell you what we are using.
What guarantee comes with the work?
Every job comes with our 12-month guarantee, and we’re fully insured.