Greater London · England
Sand Mastic in Avery Hill
Professional sand mastic in and around Avery Hill, with old sealant always removed completely.
- Cracked mastic round a front door frame
- Cement or filler used on old window joints that has cracked
- Mastic that needs renewing before redecorating
Sand mastic in Avery Hill
Sand mastic is the traditional way to point the gap between a timber window frame and the stone or brick around it. It’s a mix of sand and a linseed-oil-based binder and built up by hand. On older homes, it suits the building far better than silicone. If you are dealing with failed mastic on an exposed elevation and mastic that needs renewing before redecorating, we can help, whatever the surface.
London has a lot of flats and conversions, where windows are often on upper floors. In a converted house or block, the lease normally says who is responsible for the windows, so it’s worth checking before booking, and access in Avery Hill is something to talk through when you book.
You are covered for a year from the day we finish. If anything is not right with it, phone 0345 464 0079 or send us an email.
- Place
- Avery Hill (SE9, DA15, DA16)
- Region
- Greater London
- Cover
- 12 months on all our work
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Keeping the joints in good condition
How long the joints last depends on use and care. We suggest:
- Check with your local planning authority if your home is listed
- Leave the new mastic unpainted
- Avoid heavy scraping on the mastic joint
- Check the mastic when you check the paintwork
Leave the new mastic alone while it firms up. It skins over quickly but needs longer to fully harden.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry so early renewal protects both.
Quotes for sand mastic in Avery Hill
For a quick quote, just ask. What matters most is:
- The size of the job
- The number of rooms or windows
- The old material and how stubborn it is
- Which sealant suits the joint
What you pay reflects the work, not guesswork. That’s why we ask about the job first and agree the price before starting.
Asking for a quote
When you contact us, these details help:
- If it’s domestic, commercial or a hotel
- Where the property is
- What the problem is, such as mould, gaps, leaks or cracking
- Photos by email, if that is easy
Call for a quick quote, or send an email if you’d rather. Tell us about the joints that need doing and we will talk you through the work and give you a clear price.
Should I try it myself first?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Also near Avery Hill
What else we do in Avery Hill
What sand mastic looks like in Avery Hill
In London conversions and blocks, the lease decides who is responsible for the frames, so check that before booking. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Avery Hill is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. Managing a site like Stationers' Crown Woods Academy? Then the mastic around its windows and doors needs looking after like any other building’s.
Avery Hill is about 1 mile north-east of Eltham, in Greater London. Avery Hill gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Our Greater London coverage runs to 764 places, Avery Hill among them. There’s also a page for London, roughly 8 miles from Avery Hill.
Postcode districts we cover here for sand mastic: SE9, DA15 and DA16. That includes homes and businesses on Bexley Road, Glenure Road and Perpins Road. Main roads around Avery Hill include the A210, which makes travel easy. We also cover the places around Avery Hill: Blackfen (1 mile east), Eltham (1 mile south-west), New Eltham (1 mile south), Falconwood (1 mile north-east) and Well Hall (1 mile west). Further out, we also cover London (8 miles north-west), City of Westminster (11 miles north-west), Marylebone (11 miles north-west), Kensington (12 miles west), St Pancras (10 miles north-west) and Shoreditch (8 miles north-west).
Local landmarks in Avery Hill
Around Avery Hill, our work takes us to homes and buildings near Shoulder of Mutton Green and Alderwood Primary School. Avery Hill’s nearest station is Falconwood station, about 0.6 miles north. Well-known places in the area include Greenwich Castle (3.8 miles north-west) and Metropolitan Police Museum (1.7 miles south-east). Open spaces near Avery Hill include Summer Hill and The Tarn.
Why deal with it now?
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. In a flat in Avery Hill, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you’re not sure whether it needs doing, phone 0345 464 0079 or send us an email and we’ll give you an honest view and a quote.
Why choose Mr Mastic in Avery Hill
- 180+ five-star Google reviews
- More than 20 years in sealant work
- Old sealant always removed completely
- Neat joints and a tidy finish
Take a look at what affects the cost or customer reviews.
How the job changes by surface
Sash and case windows
A sash window’s box frame sits in the masonry opening. Sand mastic seals the joint round it.
Period and listed homes
Period homes look their best with traditional materials, and sand mastic is one of them.
What happens on the day
There isn’t much for you to do on the day. Show us the job and we will take it from there. The job generally takes a few hours for a single window, longer for several. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Avery Hill. A visitor permit or a nearby bay makes the visit run more smoothly.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic isn’t too thick.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Keep children and pets away from the work area
- Where the joints are inside, avoid wetting them before we arrive
How to get a quote
There’s no standard price list. Instead, we give you a clear quote for your job. To get started, call 0345 464 0079 or drop us an email.
Related advice
FAQs for Avery Hill
Do you cover Avery Hill for sand mastic?
Yes, Avery Hill is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or drop us an email and tell us what needs doing, and we will send you a clear quote.
Do you work for landlords with property near Falconwood station?
Yes, landlords and agents are among the people we work for. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we will give you a clear price.
Do I need permission for sand mastic on a listed building?
Your local planning authority is the one to ask. They’ll tell you if consent is needed for work to your windows.
What do you need from me for a quote?
Tell us what needs doing and where, with photos by email if possible. If we need more, we’ll ask.
Where are you based?
Mr Mastic is based in Crawley. Our applicators cover Avery Hill, along with the rest of our area.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done and we will quote it together.
Can new sealant go over the old?
No, it will not last. It may look fine at first, but the new layer lifts away from the old one. The old sealant has to come out completely.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint before resealing.
Signs you need sand mastic in Avery Hill
Paint, silicone or cement used over old mastic causes problems. They do not move with the timber and we normally remove them.
It’s worth asking for a quote if you see:
- Silicone on a period window that looks wrong
- Mastic dropping out of the joint
- Gaps between timber frames and stone or brick
- Mastic round period door frames that has failed
If you let a flat or house near Falconwood station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Comparing quotes
- Which colour the sealant will be
- What guarantee comes with the work
- What preparation is included
- Whether the sealant suits the joint