Greater London · England
External Mastic in The Hale
External mastic in The Hale from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Failed seals between different materials
- Joints with sealant missing in places
- Plants rooting in failed movement joints
How we handle external mastic in The Hale
We’re ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Some surfaces need a primer before sealing, and we don’t skip that step. Common call-outs are for leaking joints around cladding and façade panels and movement joints filled with mortar instead of sealant, on façade panels, joints between brick and frames and render & cladding joints.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in The Hale, tell us how high the joints are and how to reach the back of the building.
You’re covered for a year from the day we finish. If there’s a problem with it, please phone 0345 464 0079 or drop us an email.
- Where
- The Hale (HA8, NW7)
- Region
- Greater London
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
DIY versus a professional finish
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
The process
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The work itself takes a few hours for a handful of joints, longer for a whole elevation from start to finish. In a London area like The Hale, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Let us know if you’ve seen damp or leaks
- Mention any parking rules near the property
- Where the joints are inside, avoid wetting them before we arrive
Get a quote
Getting a quote is simple: let us know the job and the location. Photos by email help us understand the job, and we will take it from there.
Advice
Walls and rooflines in The Hale
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. With historic houses such as Headstone Manor (about 4.4 miles south-west) nearby, there’s older building stock in the area around The Hale as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material.
Homes close to John Keble Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant. As a London address, The Hale can be tricky for parking: let us know about parking bays, permits or a driveway. Schools such as Mathilda Marks-Kennedy Jewish Primary School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s.
The Hale is about 1 mile north of Burnt Oak, in Greater London. Across the HA8 area, we cover external mastic for homes and businesses. The Hale is one of 764 towns and villages in Greater London we cover for external mastic. There’s also a page for London, roughly 11 miles from The Hale.
Postcode districts we cover here for external mastic: HA8 and NW7. External mastic is available to properties on Hale Lane, Farm Road and Dean's Lane and the roads around them. The Hale sits on or near the A5100, which makes travel easy. Close by, we work in Edgware (1 mile west), Broadfields Estate (1 mile north-west), Burnt Oak (1 mile south), Mill Hill (1 mile east) and Edgware Bury (1 mile north-west). Further out, we also cover London (11 miles south-east), City of Westminster (9 miles south-east), Marylebone (9 miles south-east), Kensington (9 miles south), St Pancras (9 miles south-east) and Shoreditch (10 miles south-east).
Around The Hale
In The Hale, that means homes and buildings near St Martin's School Brentwood, The Northgate School and Rising Sun pub and the streets around them. The Hale’s nearest station is Mill Hill Broadway station, roughly 0.7 miles south-east of the centre. Other landmarks nearby include Broadwalk Centre (0.8 miles south-west) and Edgware Community Hospital (1 mile south-west). For a walk, there’s Mill Hill Old Railway Nature Reserve and Darland's Lake.
Places near The Hale
What else we do in The Hale
How to look after the new joints
Aftercare is simple, and it makes a real difference:
- Tell anyone working on the walls about the movement joints
- Have failed joints looked at early
- Avoid pressure-washing directly into sealant joints
- Check the sealant is paintable before painting near it
Do not let soil, plants or ivy build up against the new joints. Damp material against the sealant shortens its life.
Act while the splits are small. At that stage it’s a simple cut out and reseal before water has had years to get in.
Different surfaces, different methods
Cladding and façade panels
Where a cladding system has its own specified sealant, we follow it. Send us any details you have about the façade.
Brickwork movement joints
Brick walls have vertical movement joints to absorb expansion. We reseal them with a low-modulus sealant over backing rod coloured to suit the wall.
Why it’s worth doing now in The Hale
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That protects surfaces like brick, render and concrete. Too stiff a sealant can pull at the edges and break them. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, ring 0345 464 0079 or email us for an honest opinion and a quote.
What you get with us
- Rated 4.9 stars on Google
- Any old sealant cut out fully, not covered over
- We’re fully insured
- Anti-fungal silicone where joints get wet
Read what affects the cost or our reviews.
Quotes for external mastic in The Hale
Jobs vary more than people expect. What affects the quote:
- The size of the job
- Whether the work is at height
- How many rooms, windows or areas are involved
- When we can work, for business premises
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
What to tell us for a quote
To make quoting easier, let us know:
- A few pictures by email, if you can
- If it’s domestic, commercial or a hotel
- The rough size of the job
- What the problem is, such as mould, gaps, leaks or cracking
Quotes start with a quick conversation. Describe the problem, the location and the size of the job. When it suits you, phone 0345 464 0079 or send us an email.
FAQs for The Hale
Can you help a landlord with a rental near Mill Hill Broadway station?
Yes, we work for letting agents and landlords. You can phone 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before we start.
Do you cover The Hale for external mastic?
Yes, The Hale is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or drop us an email and tell us what needs doing.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done.
How much does external mastic cost in The Hale?
Every job is different, so each one gets its own quote. For a quick quote, phone 0345 464 0079 or email us and tell us what needs doing and where.
Do the sealants smell?
Possibly a little. It fades as the sealant cures.
Can a movement joint be filled with mortar?
No, not if it’s a movement joint. Pointing it stops it working. A flexible sealant is the right fill.
Can you seal joints between render and window frames?
Yes. Joints between dissimilar materials are a big part of external work. The sealant is chosen to bond to both sides with primer where required.
Are you insured?
Yes. We’re fully insured for domestic and commercial work.
When it isn’t the sealant
New sealant cannot fix everything, and we’d rather say so up front. Sealant will not put right:
- Loose or hollow render, which needs re-rendering
- Adding movement joints to masonry that has none
- Cracked brickwork or render that needs a builder or plasterer
Not sure which it is? You can ring 0345 464 0079 or send us an email and we will tell you honestly before you book.
Joints and surfaces we work on
- Joints between brick and frames
- Concrete & block
- Copings & trims
- Brickwork movement joints
- Render & cladding joints
- Façade panels