Greater London · England
East Barnet Window Mastic
Window mastic in East Barnet from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Damp patches on the reveal after heavy rain
- Leaking joints at the ends of sills
- Whistling draughts around closed windows
Window mastic for homes and businesses in East Barnet
Most frames have an outside joint and an inside one. The external joint is the weather seal; the internal joint closes the gap to the plaster and stops draughts. Either or both can be done. If you have a bead that doesn’t match the frame and water coming in at the bottom corners of a door, we can help.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. Over the years, the sealant around them shrinks, cracks and pulls away, letting in draughts and water.
A 12-month guarantee comes with the work, just as it does everywhere we cover.
- Location
- East Barnet (N20, EN4, N14)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Do you need window mastic in East Barnet?
Joint shape matters as much as the product. A skim of sealant over a wide gap soon tears, while a joint packed solid can’t stretch. Backing rod sets the right depth.
Keep an eye out for these signs:
- Mastic that has split away from the wall
- Cracked internal joints between frame and plaster
- Sealant in the wrong colour for the frame
- Leaking joints at the ends of sills
East Barnet is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
What to look for in a quote
- Whether you can choose the colour
- What happens if they find a problem under the old sealant
- What product goes in the joint
- Who turns up on the day
How to look after the new joints
No joint lasts for ever, but care makes a real difference. A few tips:
- Repaint timber before it’s bare
- Keep drainage slots and sill grooves clear
- Paint up to the joint, not over it
- Keep solvents and bleach off the sealant
Have a look at the joints once a year, ideally after winter. Small splits are simple to catch before they leak, and if anything looks wrong, just ring 0345 464 0079 or send us an email.
On timber windows, water behind the joint can lead to rot. Once wood has rotted, it needs repair before it can be sealed, so it pays to reseal before that happens.
Honest limits
New sealant can’t fix everything, and we’ll tell you before work begins. Sealant won’t put right:
- Worn gaskets, brush seals or a door that has dropped
- Soft or decayed wood in the frame
- Damp coming through the wall itself rather than the frame joint
Not sure which it is? You can ring 0345 464 0079 or email us and we will tell you honestly before booking.
Joints and surfaces we work on
- Timber windows & doors
- Aluminium frames
- Patio & French doors
- uPVC windows
- Composite doors
- Window sills
Why deal with it now?
Resealing frames is a short job: the visit takes a few hours for a handful of frames, longer for a whole house. Wait for damp to appear and there may be plaster and decorating to sort out too. 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 East Barnet, the repair is bigger than the sealant job would have been.
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote.
What you get with us
- ARBOMaster approved applicator
- Old sealant always removed completely
- A choice of colours where the product allows
- We leave the area clean and tidy
Take a look at what affects the cost and customer reviews.
Work for landlords, hotels and businesses
Whether it’s one flat or a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
We work for landlords and letting agents as well as householders. Resealing between tenancies is a simple way to keep a property in good order.
Frames and glazing around East Barnet
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. 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 a converted house or block, who looks after the windows depends on the lease, so check that before booking.
Homes close to St Mary the Virgin include some older properties, and the joint between an old wall and a newer frame is normally the first place rain gets in. For site and facilities teams at buildings such as Church Hill School, its window and door frames need their mastic kept sound, just like a home’s.
East Barnet is about 1 mile north-east of Whetstone, in Greater London. Jobs in East Barnet get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. 764 places in Greater London are on our list, large and small. We also work in London, around 10 miles away.
Work in N20, EN4 and N14 is quoted and booked the same way as anywhere else. Window mastic is available to properties on Dene Road, Pine Road and Capel Road and the roads around them. Neighbouring places we cover for window mastic include 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). We also work in nearby towns such as 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).
Around East Barnet
Around East Barnet, our work takes us to homes and buildings near Oak Hill Park, Salcombe School and East Barnet School, among other places. Also close by are The Cavalier pub (within half a mile south) and Francis Skaryna Belarusian Library and Museum (1.8 miles south-west). For rail, the closest station is Oakleigh Park station, roughly 0.5 miles north-west. Other landmarks nearby include Grand Arcade (1.7 miles south-west) and Finchley Memorial Hospital (2.2 miles south-west). The countryside around East Barnet includes Oakleigh Park Rail Cutting and Darland's Lake.
What happens on the day
Most of a good job is in the preparation, so that’s where we spend the time. Joints are cleaned back and dried before anything new goes in. In total, it generally takes anything from an hour or two to a full day, depending on how many frames there are. In East Barnet, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We check each frame and agree which ones need doing.
- We remove the old mastic and clean the frame and the wall.
- We fit backing rod in deep gaps so the sealant is the right depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Every joint is checked before we leave.
How to prepare
- Let us know about parking restrictions
- On commercial sites, let us know about site rules
- Clear items away from the joints we are working on
How to get a quote
We do not publish a price list, as no two jobs are quite the same. Instead, we give you a clear price for your job. To arrange one, phone 0345 464 0079 or email us.
Related advice
How the job changes by surface
Timber windows & doors
Timber moves with moisture as well as heat, so a flexible sealant is essential. We seal onto sound, dry paintwork or timber.
Patio & French doors
Heavy door frames can move more than windows. A flexible sealant copes with that without cracking.
Nearby places to East Barnet
What else we do in East Barnet
East Barnet: your questions answered
Do you cover East Barnet for window mastic?
Yes. Our work covers London and the South East, and East Barnet is part of that. You can ring 0345 464 0079 or email us and tell us what needs doing.
Do you work for landlords with property near Oakleigh Park station?
Yes, we work for landlords and letting agents. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we’ll send you a clear quote.
Where is Mr Mastic based?
Our base is Crawley. Our area covers South East England, London and Scotland.
Is it worth trying it myself?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
Do you have insurance?
Yes. Mr Mastic is fully insured.
Do you have sealant for grey or black windows?
Yes. White, brown, anthracite grey, black and clear sealants are all available, so the joint suits the frame.
Will resealing my frames help with draughts?
Yes, where the draught is at the frame edge. We check where the draught is before we start.
Will there be a smell?
Possibly a little. Any smell clears as the sealant cures.