Greater London · England
Sand mastic for sash & case windows in East Barnet, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for householders, landlords and businesses in East Barnet. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Mastic worn away on windows facing the weather
- Old cement repairs round a window that have failed
- Cracked mastic round a front door frame
Sand mastic in East Barnet, done properly
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditionally, sand mastic is left unpainted and we will advise if you’re redecorating. We work on brick reveals, period & listed homes and sash and case windows, and people most often call us about mastic worn away on windows facing the weather and silicone on a period window that looks wrong.
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.
Big or small, you get the same 12-month guarantee in East Barnet and across Greater London.
- Place
- East Barnet (N20, EN4, N14)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
For landlords and businesses
Letting agents often deal with us directly. Tell us the address, the job and how access works and we’ll quote.
In hotels, rooms out of use cost money, so the work can be planned room by room. Hotel work is part of what we do, alongside homes and businesses.
East Barnet homes and the weather
In London conversions and blocks, the lease decides who is responsible for the frames, so check that before booking. With historic houses such as Heath Hall (about 4.2 miles south) nearby, there’s older building stock in the area around East Barnet as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
Managing a site like Church Hill School? Then the mastic around its windows and doors needs looking after like any other building’s. For landlords with property near Oakleigh Park station, any sash windows need sound mastic to keep draughts and rain out.
East Barnet is about 1 mile north-east of Whetstone, in Greater London. If you need sand mastic in East Barnet, it’s easy to get a quote: please ring 0345 464 0079 or email us. We are based in Crawley and cover Greater London. Across Greater London, we cover 764 places, and East Barnet is one of them. We also work in London, around 10 miles away.
Postcode districts we cover here for sand mastic: N20, EN4 and N14. You’ll find streets such as Dene Road, Pine Road and Capel Road, all of which we cover. Close by, we work in Osidge (1 mile east), Brunswick Park (1 mile south-east), New Barnet (1 mile north-west), Whetstone (1 mile south-west) and Oakleigh Park (1 mile south-west). Further out, we also cover London (10 miles south), City of Westminster (8 miles south), Marylebone (8 miles south), Kensington (10 miles south), St Pancras (8 miles south) and Shoreditch (8 miles south-east).
Landmarks near East Barnet
In East Barnet, that means homes and buildings near Oak Hill Park, Salcombe School and East Barnet School. Also close by are The Cavalier pub (under half a mile south) and Francis Skaryna Belarusian Library and Museum (1.8 miles south-west). East Barnet’s nearest station is Oakleigh Park station, roughly 0.5 miles north-west of the centre. Nearby you will also find Grand Arcade (1.7 miles south-west) and Finchley Memorial Hospital (2.2 miles south-west). Green spaces nearby include Oakleigh Park Rail Cutting and Darland's Lake.
Towns and villages near East Barnet
More services for East Barnet
What affects the cost of sand mastic
Every job gets its own quote. These are the things that affect it:
- Mould in or behind the old joints
- The type of sealant required
- How many areas need sealing
- The amount of work
The cost depends on how much there is to do, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before work begins.
Asking for a quote
Photos by email are helpful but not essential. Please mention:
- Photos by email, if that is easy
- What the problem is, such as mould, gaps, leaks or cracking
- The type of property
- Any access issues, like height or stairs
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job, and we’ll come back to you with a quote.
How it works
Before we leave, we go over the finished joints with you and explain the cure time. The work normally takes a few hours for a single window, longer for several, depending on how much there is to do. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in East Barnet. A visitor permit or a nearby bay makes the visit run more smoothly.
- Each surround is checked first.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic is not too thick.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
How to prepare
- Mention any leaks or damp you’ve noticed
- Move anything stored near the joints
- Mention if the joints have been sealed before
Getting a quote
Every job is quoted individually. Just phone 0345 464 0079 or email us with the details and send photos if you have them.
Related advice
Signs you need sand mastic in East Barnet
Sand mastic slowly weathers. It hardens, cracks and starts to come away on the stone or timber.
Any of these means the joints need attention:
- Patchy fillers round a sash window
- Tired mastic found when preparing windows for paint
- Mastic dropping out of the joint
- Weathered mastic on the most exposed windows
If you live in an older home near St Mary the Virgin, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Before booking anyone
- What preparation is included
- Which colour the sealant will be
- How long the guarantee is
- Which sealant they’ll use, and why
Your questions about sand mastic in East Barnet
Do you work for landlords with property near Oakleigh Park station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or email us and tell us about the property, and we will give you a clear quote.
Is parking a problem for a job in East Barnet?
Parking in East Barnet, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Do you come to East Barnet?
Yes. We are based in Crawley and work across South East England, London and Scotland, East Barnet included.
How long does sand mastic take to go off?
A skin forms quite soon, but full hardening takes longer. We will explain what to expect before we leave.
Should I use sand mastic or silicone?
Sand mastic normally suits period timber windows best. On modern frames, we’d normally use a flexible sealant.
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. Larger jobs naturally take longer.
Which products do you use?
We choose the sealant for the joint, not the other way round. Where it moves, gets wet or faces the weather makes a difference, and we will tell you what we are using.
Can you do several jobs on one visit?
Yes. Just list everything you need and you’ll get one quote.
How the job changes by surface
Period and listed homes
On a listed home or in a conservation area, the right material matters. Sand mastic is often the preferred finish.
Sash and case windows
A sash window’s box frame sits in the masonry opening. The gap round it is pointed with sand mastic.
DIY versus a professional finish
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.
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
When it is not the sealant
We will always be straight with you, so here’s what sealant cannot fix:
- Sash cords, weights and draught-proofing of the sashes
- Damaged stone surrounds
- Decayed frames that need repair
If you’re not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer before you book.
Joints and surfaces we work on
- Timber door frames
- Period & listed homes
- Stone surrounds
- Sash and case windows
- Brick reveals
- Tenement windows