Greater London · England
External & façade joints in Green Street Green, Greater London
Movement joints in Green Street Green need attention? We cut out the old, prepare the joints and apply the right sealant, with a one-year guarantee.
- Leaking joints around cladding and façade panels
- Movement joints with cracked, split or missing sealant
- Failed seals between different materials
When it is not the sealant
A few problems are outside what sealant work can do:
- Walls that need new movement joints cut into them
- Cracking across the wall rather than at a joint
- 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.
Surfaces we seal
- Façade panels
- Render & cladding joints
- Concrete & block
- Brickwork movement joints
- Joints between brick and frames
- Copings & trims
External mastic in Green Street Green, done properly
On houses, flats and commercial buildings across Green Street Green, we reseal joints in brickwork, render, cladding and façade panels. Every joint gets the same careful preparation: clean joint faces and the right depth. Common call-outs are for brick movement joints where the sealant has split and moss and dirt in joints with no sealant left, across render & cladding joints, brickwork movement joints and façade panels.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. In Green Street Green, joints up high may need ladders or other access, which is worth talking through when you book.
Whatever the size of the job, it’s backed by our one-year guarantee in Green Street Green and across Greater London.
- Place
- Green Street Green (BR6)
- Region
- Greater London
- Cover
- One year on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Should I try it myself first?
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
Questions from Green Street Green
Do you work for landlords with property near Chelsfield station?
Yes. We work for landlords and agents as well as householders. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Do you cover Green Street Green for external mastic?
Yes, Green Street Green is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or drop us an email and tell us what needs doing, and we’ll give you a clear price.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done and you will get one quote.
Will there be a smell?
Sometimes, a little. It fades as the sealant cures, and ventilation helps.
Do you work for hotels and businesses?
Yes. Hotels, offices and other businesses use us, and we’re fully insured.
Can new sealant go over the old?
No. New silicone won’t bond to old silicone, and anything trapped underneath, including mould and water, stays there. We remove it all first.
Where do you work from?
Our base is Crawley. We work across South East England, London and Scotland.
What colours does the sealant come in?
The sealant colour is picked to suit the wall. There’s a wide choice of exterior colours.
What affects the quote in Green Street Green
We quote each job individually. This is what makes a difference:
- Any mould that needs treating
- The size of the job
- The type of sealant required
- Any working-time requirements on site
The cost depends on the size of the job, how hard the old material is to remove and access to the work. You will have a clear quote before any work starts.
What to tell us for a quote
When you contact us, these details help:
- Whether it’s a home or a business
- The rough size of the job
- Pictures of the joints, sent by email
- Where the job is, and your postcode
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will talk you through what we’d do. When it suits you, phone 0345 464 0079 or send us an email.
How it works
On the day, there’s very little for you to do. Show us the job and we will take it from there. The work itself takes a few hours to a few days, depending on the length of joint and the access from start to finish. In Green Street Green, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- Old sealant and any debris are cut and raked out.
- The joint faces are cleaned and primed where the sealant needs it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Let us know if you’ve seen damp or leaks
- Let us know about stairs, lifts or work at height
Ask for a quote
Every job is quoted individually, so start by telling us what you need. Simply ring 0345 464 0079 or drop us an email and describe the job and send pictures if you have them.
Read more
Also near Green Street Green
More services for Green Street Green
Common problems we fix in Green Street Green
Many joints fail because they were sealed too deep or with nothing behind them. If the sealant sticks to the back as well as the sides, it can’t stretch and tears as soon as the joint widens.
Common reasons people contact us include:
- Sealant pulling away from one side of the joint
- Brick movement joints where the sealant has split
- Failed seals between different materials
- Rigid filler in a joint that should flex
Homes close to St Mary's Church include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
Comparing quotes
- Who turns up on the day
- What guarantee comes with the work
- What the cure time is
- Whether the sealant suits the joint
What the job involves on each surface
Copings and trims
Metal and stone copings both move with temperature, so the joints need a sealant that stays flexible in all weathers.
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joints work hard every day. The sealant is chosen with that in mind.
Why deal with it now?
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That protects surfaces like brick, render and concrete. Too stiff a sealant can pull at the edges and break them. Damp from a failed joint spreads quietly in older London brickwork and timber, and by the time it shows on a wall or ceiling in Green Street Green, the repair is bigger than the sealant job would have been.
Doing several joints on one visit normally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
Why choose Mr Mastic in Green Street Green
- 180+ five-star Google reviews
- Approved under the ARBOMaster scheme
- Sanitary silicone with an anti-fungal additive in wet areas
- We never seal over old sealant
Take a look at our cost guide or what customers say.
External mastic in Green Street Green: local notes
The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Down House (about 2.1 miles south-west) are a reminder that the area around Green Street Green has older buildings as well as new. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material.
For site and facilities teams at buildings such as Green Street Green Primary School, larger buildings have long runs of movement joint that eventually need resealing. Rented homes near Chelsfield station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Green Street Green is about 2 miles south of Orpington, in Greater London. Homes, rented property, offices and hotels in Green Street Green can book us for external mastic, old or new, large or small. Every job comes with our one-year guarantee. Our Greater London coverage runs to 764 places, Green Street Green among them. London is on our list too, about 13 miles from Green Street Green.
Postcode districts we cover here for external mastic: BR6. You’ll find streets such as Vine Road, Laxey Road and Shire Lane, and we cover them all. If you’re just outside Green Street Green, we cover Farnborough (1 mile north-west), Hazelwood (1 mile south-west), Crofton (2 miles north), Downe (2 miles south-west) and Farthing Street (2 miles west). We also work in nearby towns such as London (13 miles north-west), City of Westminster (15 miles north-west), Marylebone (15 miles north-west), St Pancras (15 miles north-west), Shoreditch (14 miles north-west) and Hoxton (15 miles north-west).
Landmarks near Green Street Green
Typical jobs here are in homes near Queens Head pub and Hewitt's Chalk Bank, among other places. For rail, the closest station is Chelsfield station, about 0.9 miles east of the centre. Well-known places in the area include Orpington Hospital (0.8 miles north-east) and Crofton Roman Villa (1.5 miles north). Open spaces near Green Street Green include Summer Hill and Downe Bank Nature Reserve.