Greater London · England
External & façade joints in Burnt Oak, Greater London
Professional external mastic in and around Burnt Oak, with every bit of old sealant taken out first.
- Movement joints with cracked, split or missing sealant
- Failed sealant between panels on a façade
- Water getting into walls through failed joints
How we handle external mastic in Burnt Oak
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Some surfaces need a primer before sealing and we use one wherever it does. If you are dealing with sealant pulling away from one side of the joint and weeds or debris growing in open joints, we can help.
Modern London flats rely on sealed movement joints and cladding joints. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
A 12-month guarantee comes as standard, so you’re covered after we’ve gone.
- Location
- Burnt Oak (HA8, NW9, NW7)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Burnt Oak buildings and the weather
London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Managing a site like The Annunciation RC Junior School? Then larger buildings have long runs of movement joint that eventually need resealing. As a London address, Burnt Oak can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Burnt Oak is about 7 miles south-east of Watford, in Greater London. Whether you’re in the middle of Burnt Oak or further out, external mastic is available for homes and businesses alike. 764 places in Greater London are on our list, large and small. You can also see our page for London, roughly 10 miles from Burnt Oak.
Postcode districts we cover here for external mastic: HA8, NW9 and NW7. If you need external mastic at a property on East Road, Back Lane and Rill Lane or anywhere close by, our applicators can take on the job. Burnt Oak is on the A5100, which makes it straightforward to reach with everything needed for external mastic. If you’re just outside Burnt Oak, we cover The Hale (1 mile north), Edgware (1 mile north-west), Grahame Park (1 mile south-east), Little Stanmore (1 mile west) and Canons Park (1 mile west). We also work in nearby towns such as London (10 miles south-east), City of Westminster (8 miles south-east), Marylebone (8 miles south-east), Kensington (8 miles south), St Pancras (8 miles south-east) and Shoreditch (10 miles south-east).
Near you in Burnt Oak
We work in homes and buildings around St Martin's School Brentwood, Railway Hotel and Watling Park and the streets around them. The closest station to Burnt Oak is Mill Hill Broadway station, roughly 0.5 miles north-east of the centre. Nearby you will also find Church Farmhouse Museum (1.8 miles south-east) and Edgware Community Hospital (0.5 miles west). Not far away are Darland's Lake and Mill Hill Old Railway Nature Reserve.
Should I try it myself first?
A DIY attempt does not rule out a professional job. We remove it and do the joint properly.
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.
How the visit works
Once we’re on site, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. After that, the work takes anything from a few hours to several days, depending on the building. In a London area like Burnt Oak, the main things to plan are parking and access: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
How to prepare
- Let us know about stairs, lifts or work at height
- Let us know about earlier repairs to the joints
- Keep pets and children clear of the area while we work
Getting a quote
We don’t publish a price list. Instead, your job gets its own clear quote. To arrange one, call 0345 464 0079 or email us.
Advice
Burnt Oak: your questions answered
Do you work for landlords with property near Mill Hill Broadway station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Is parking a problem for a job in Burnt Oak?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Do you work for hotels and businesses?
Yes. Commercial and hotel work is a large part of what we do, as well as homes. Working times can be discussed when we quote.
Why is there a gap in my brick wall?
Brickwork, render and cladding all move a little, and planned joints take up that movement. The gap is sealed with a flexible sealant over backing rod.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
How long does external mastic last?
There’s no fixed answer: joints on exposed walls or with a lot of movement age sooner. Check them each year and reseal when they split or harden. Every job carries our 12-month guarantee.
Do you have insurance?
Yes. We are fully insured for every job we do.
Is it messy?
Very little: the area around the joints is protected first, and we tidy up before we go.
What we cannot put right
Sealant isn’t the answer to every problem, and we will tell you before work begins. Sealant will not put right:
- Walls that need new movement joints cut into them
- Cracked brickwork or render that needs a builder or plasterer
- Render that’s blown, hollow or coming away
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
Surfaces we seal
- Concrete & block
- Render & cladding joints
- Brickwork movement joints
- Façade panels
- Copings & trims
- Joints between brick and frames
When to call us in Burnt Oak
Every building moves. Brickwork grows a little over the years, blockwork and concrete shrink, and all of it moves with heat and moisture. The sealant in the movement joints takes that strain.
Signs it’s time to call us include:
- Plants rooting in failed movement joints
- Joints with sealant missing in places
- Cracked joints where brick meets render or frames
- Panel joints letting water in
Rented homes near Mill Hill Broadway station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Questions to ask before booking
- What happens if they find a problem under the old sealant
- How the joint is cleaned and prepared
- When the joint can take water or movement
- Whether the sealant suits the joint
Why act early in Burnt Oak
Sealing over the top of old mastic doesn’t hold for long. New sealant does not bond well to old, weathered sealant, so the old joint is cut out fully first. In a flat in Burnt Oak, 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.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we’ll go through it with you.
What you get with us
- Domestic, commercial and hotel work
- More than 20 years in sealant work
- 180+ five-star Google reviews
- Tidy, careful work
Read our cost guide and what customers say.
Keeping the joints in good condition
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Leave the joints unpainted unless we’ve said otherwise
- Get split or bare joints resealed while the damage is small
- Walk round the building once a year and look at the joints
- Fix overflowing gutters above sealed joints
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Gaps, plants or missing sealant in a joint are worth getting looked at. Earlier resealing means a smaller job and a better result.
What the job involves on each surface
Cladding and façade panels
Panel systems often rely on sealant between and around the panels. We reseal them with a sealant suited to the panel material.
Copings and trims
Coping joints that leak let water straight down into the wall. Resealing them is a small job that protects a lot.