Greater London · England
Leaves Green External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for Leaves Green, backed by a 12-month guarantee. Ask us for a quote.
- Moss and dirt in joints with no sealant left
- Gaps where render, brick and frames meet
- Leaking joints around cladding and façade panels
DIY sealant or a professional job?
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it does not work out, we can still put it right.
External mastic in Leaves Green, done properly
Low-level joints can usually be done from the ground. Where joints are higher up, tell us about the building when you get in touch and we will confirm what’s needed to reach them safely. We work on concrete & block, copings & trims and façade panels, and common reasons people get in touch are sealant pulling away from one side of the joint and failed sealant between panels on a façade.
Outside work in London starts with access: side passages, upper floors and where to park. For a home in Leaves Green, tell us how high the joints are and how to reach the back of the building.
We stand behind the work with a one-year guarantee, so you’re not left on your own once the job is done.
- Location
- Leaves Green (BR2)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quote
- A clear price before work begins
- Call
- 0345 464 0079
- Updated
- 26 October 2026
For landlords and businesses
We work for landlords and agents as well as householders. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
In hotels, rooms out of use cost money, so we plan the work room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
How the visit works
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The job generally takes a few hours for a handful of joints, longer for a whole elevation from start to finish. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Preparing for the visit
- For indoor joints, keep the area dry beforehand if you can
- Keep pets and children clear of the area while we work
- Let us know about parking restrictions
Get a quote
Every job is quoted individually, so start by telling us what you need. Simply ring 0345 464 0079 or email us and describe the job, and photos are welcome.
Related advice
Surface by surface
Brickwork movement joints
People sometimes point up a brick movement joint by mistake. Where one has been mortared, we cut it out and reseal it with sealant if the joint can be cleared.
Concrete and blockwork
Big joints in concrete need careful depth control. We size the backing rod to the gap so the sealant is not too deep.
FAQs for Leaves Green
Can you help a landlord with a rental near Hayes (Kent) station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can ring 0345 464 0079 or send us an email with the details for a clear quote.
Do you cover Leaves Green for external mastic?
Yes, Leaves Green is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or email us and let us know what needs doing.
What do you need from me for a quote?
Let us know what needs doing and where. If we need more, we’ll ask.
Are you ARBOMaster approved?
Yes. We’re approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
When is the sealant fully cured?
It depends on the product and the conditions. We tell you how long to leave it before we go.
When will the joints need doing again?
It depends on the exposure, the movement and the product. Treat it as a maintenance item and look at it yearly and renew it when it starts to fail.
Will the new joint stand out?
We choose a sealant colour to suit the brick, stone or render so the joint blends in. Exterior sealants come in a good range of colours.
Is there a guarantee?
Yes. Each job is guaranteed for twelve months, large or small.
Outside joints around Leaves Green
Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts.
Letting a property close to Hayes (Kent) station? Then outside joints that have cracked can let damp into a rental, so check them between lets. If you live in an older home near Keston Parish Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Leaves Green is about 4 miles south of Bromley, in Greater London. Jobs in Leaves Green get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. We cover 764 towns and villages across Greater London, large and small. There’s also a page for London, roughly 12 miles from Leaves Green.
Work in BR2 is quoted and booked the same way as anywhere else. If you need external mastic at a property on Ashmore Lane and Main Road or a nearby road, we can help. Neighbouring places we cover for external mastic include Farthing Street (1 mile north-east), Downe (1 mile east), Nash (1 mile north-west), Luxted (1 mile south-east) and Keston (2 miles north). We also work in nearby towns such as London (12 miles north-west), City of Westminster (15 miles north-west), Marylebone (15 miles north-west), Kensington (15 miles north-west), St Pancras (14 miles north-west) and Shoreditch (14 miles north).
Local landmarks in Leaves Green
Locally, jobs take us to homes and businesses close to The Kings Arms and South Park. For rail, the closest station is Hayes (Kent) station, roughly 2.8 miles north of the centre. Well-known places in the area include Bethlem Museum of the Mind (3 miles north) and Princess Royal University Hospital (2.2 miles north-east). Open spaces near Leaves Green include Nore Hill and West Kent Golf Course nature reserve.
What affects the cost of external mastic
For a quick quote, just ask. What matters most is:
- How easy the joints are to reach
- Working hours on commercial sites
- Mould in or behind the old joints
- How much old sealant there is and how hard it is to remove
Combining jobs into one visit usually makes better use of the time than several visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
Helping us quote
Before you ask for a quote, have a think about:
- A few pictures by email, if you can
- How we’d reach the joints
- Whether it has been sealed before
- What’s wrong with the joints now
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. A few pictures by email make the job easier to understand, and we will come back to you with a quote.
Looking after it afterwards
A little care helps the new joints last. We recommend:
- Make sure movement joints aren’t pointed over
- Fix overflowing gutters above sealed joints
- Get split or bare joints resealed while the damage is small
- Point out the joints to other trades
Don’t let soil, plants or ivy build up against the new joints. Damp material against the sealant shortens its life.
If you can see gaps, plants or bare sections in a joint, have it checked. Early work is quicker and leaves a better finish.
Do you need external mastic in Leaves Green?
The wrong product in a moving joint is a classic cause. A high-modulus or general-purpose sealant can be too rigid for a busy joint, and it tears off the sides.
The problems people normally mention when they call are:
- Joints where the bead has come unstuck
- Failed seals between different materials
- Brick movement joints where the sealant has split
- Rain getting behind render or cladding at a joint
For site and facilities teams at buildings such as Meridian High School, larger buildings have long runs of movement joint that eventually need resealing.
Before booking anyone
- How long the guarantee is
- Are they insured?
- Which colour the sealant will be
- How much experience the applicator has