Greater London · England
External & façade joints in Hadley, Greater London
Professional external mastic in and around Hadley, with every bit of old sealant taken out first and a 12-month guarantee.
- Panel joints letting water in
- Movement joints with cracked, split or missing sealant
- Weeds or debris growing in open joints
External mastic in Hadley
For buildings in Hadley, we reseal external joints of all kinds, from brick movement joints to cladding panels. Every joint gets the same careful preparation: clean joint faces and the right depth. Typical jobs include movement joints with cracked, split or missing sealant and joints where the bead has come unstuck, on copings & trims, render & cladding joints and concrete & block.
Outside work in London starts with access: side passages, upper floors and where to park. In Hadley, joints up high may need ladders or other access, which is worth talking through when you book.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Place
- Hadley (EN5, EN4)
- Wider area
- Greater London
- Cover
- One year on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
How it works
The work is kept neat and contained to the area we are working on, so you can carry on as normal. Expect the work to take a few hours for a handful of joints, longer for a whole elevation, and we tell you how long to leave it before we go. For a job in Hadley, parking and access are the things to plan: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Let us know about earlier repairs to the joints
- Tell us if parking is tricky
- Keep pets and children clear of the area while we work
Ask for a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints.
Read more
External mastic in Hadley: local notes
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you let a flat or house near New Barnet station, split movement joints are easy to miss on a rental until damp shows inside. If you look after a building such as Susi Earnshaw Theatre School, its movement joints, gutters and trims need looking after like any other building’s.
Hadley is about 1 mile north-west of Barnet, in Greater London. Anywhere in EN5, our applicators can take on external mastic. Our Greater London coverage runs to 764 places, and Hadley is one of them. We also work in London, around 12 miles away.
We work across EN5 and EN4 for external mastic and the streets around it. Streets in the area include Byng Road, Park Road and Dury Road. Hadley is on the A1081, so it’s easy for us to get to with everything needed for external mastic. Neighbouring places we cover for external mastic include High Barnet (1 mile west), Kitts End (1 mile north), Arkley (1 mile south-west), Totteridge (1 mile south) and Dancers Hill (2 miles north). Larger places within reach include London (12 miles south-east), City of Westminster (10 miles south), Marylebone (10 miles south), Kensington (11 miles south), St Pancras (10 miles south) and Shoreditch (10 miles south-east).
What’s near Hadley
Around Hadley, our work takes us to homes and buildings near Foulds School, Queen Elizabeth's Girls' School and Ye Olde Monken Holt pub, among other places. The closest station to Hadley is New Barnet station, roughly 1.3 miles south-east. Nearby you will also find Barnet General Hospital (0.7 miles south-west) and Spires Shopping Centre (under half a mile south-west). Open spaces near Hadley include Darland's Lake and King George's Fields (Monken Hadley).
Work for landlords, hotels and businesses
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.
If you manage several properties in or around Hadley, jobs at different addresses can go on one quote. Just tell us the addresses and what each one needs, and photos by email help.
Hadley questions
Do you cover Hadley for external mastic?
Yes. Our work covers London and the South East, and Hadley is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job.
Can you help a landlord with a rental near New Barnet station?
Yes, landlords and agents are among the people we work for. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
Should I point up the gap in my brickwork?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose and can lead to cracking. We’ll reseal it with a flexible sealant.
When is the sealant fully cured?
Different products cure at different speeds, so follow the cure time we give you.
What do you put in the joint?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We explain the product when we quote.
Why is there a gap in my brick wall?
A vertical gap in a long brick wall is normally a movement joint. It lets the bricks expand without cracking, and it should be sealed with a flexible sealant.
What is backing rod for?
The foam is closed-cell backing rod. It stops the sealant going in too deep and bonding to three sides so it can flex with the joint.
How long does external mastic last?
That depends on the wall, the weather and the movement. Signs to watch for are cracking, hardening and gaps at the edges.
Why it’s worth doing now in Hadley
Mortar or ordinary filler might look like a quick way to close an open joint, but it locks the joint solid. The movement then cracks the brickwork or render nearby. The correct repair is a flexible sealant with the right backing. In a flat in Hadley, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
Why book with us
- ARBOMaster approved applicator
- Neat joints and a tidy finish
- White, clear, grey or another colour, product permitting
- Any old sealant cut out fully, not covered over
Read our cost guide and customer reviews.
What we cannot put right
In fairness, there are a few things sealant will not fix:
- Adding movement joints to masonry that has none
- Structural movement, which needs a surveyor or engineer
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
If you are not sure, just call 0345 464 0079 or drop us an email and we’ll give you a straight answer.
Where we work in Hadley
- Concrete & block
- Brickwork movement joints
- Copings & trims
- Joints between brick and frames
- Façade panels
- Render & cladding joints
DIY sealant or a professional job?
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
Towns and villages near Hadley
What else we do in Hadley
How we quote for external mastic
For a quick quote, just ask. The main things that affect it are:
- Any working-time requirements on site
- Whether the work is at height
- Any mould that needs treating
- Which sealant suits the joint
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, ring 0345 464 0079 or send us an email for an honest opinion and a quote.
What to tell us for a quote
There’s no need for technical detail. Just tell us:
- A few pictures by email, if you can
- What’s wrong with the joints now
- Whether it’s a home or a business
- The address or postcode of the job
For a quick quote, get us on the phone, or email us if that’s easier. Tell us about the joints that need doing and we’ll explain what’s involved before giving you a price.
What we are called out for in Hadley
Poor preparation causes many early failures: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
Any of these means the joints need attention:
- Moss and dirt in joints with no sealant left
- Gaps where render, brick and frames meet
- Weathered mastic that no longer stretches
- Rigid filler in a joint that should flex
Homes close to Christ Church include some older properties, and old and new materials meet at the roofline and walls, which is where sealant earns its keep.
What to look for in a quote
- What happens if the job turns out different
- Is the old sealant removed completely?
- Whether VAT is included
- How much experience the applicator has