Greater London · England
External & façade joints in Chelsfield, Greater London
Problem with your movement joints in Chelsfield? We cut out the old, prepare the joints and apply the right sealant, with a one-year guarantee.
- Sealant that has lost its bond to the brick or render
- Movement joints filled with mortar instead of sealant
- Cracked joints where brick meets render or frames
Questions from Chelsfield
Is parking an issue for external mastic in Chelsfield?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Can you help a landlord with a rental near Chelsfield station?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before we start.
Are you insured?
Yes, we are fully insured for every job we do.
How long will you be here?
It depends on the size of the job, but as a guide it takes a few hours to a few days, depending on the length of joint and the access. We will give you a better idea when we quote.
Where do you work from?
Our base is Crawley, with over 20 years’ experience. We work across South East England, London and Scotland.
Why is there a gap in my brick wall?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It should be filled with flexible sealant, never mortar.
How do I get a quote for external mastic in Chelsfield?
Every job is different, so each one gets its own quote. To get one, ring 0345 464 0079 or send us an email and let us know what needs doing and where.
Is it messy?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
External mastic for homes and businesses in Chelsfield
External mastic is a job where short cuts show quickly. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We take the old material out and do it properly. If you have panel joints letting water in and sealant that has lost its bond to the brick or render, we can help, whatever the surface.
Outside work in London starts with access: side passages, upper floors and where to park. In Chelsfield, joints up high may need ladders or other access, which is worth talking through when you book.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Chelsfield (BR6)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- A clear price before we start
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. Several properties can go on one quote.
If you manage several properties in or around Chelsfield, jobs at different addresses can be quoted together. Send us the addresses and the work at each, and photos by email help.
DIY versus a professional finish
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 doesn’t work out, we can still put it right.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
Looking after it afterwards
A little care helps the new joints last. We recommend:
- Avoid pressure-washing directly into sealant joints
- Make sure movement joints are not pointed over
- Show decorators and builders where the movement joints are
- Get split or bare joints resealed while the damage is small
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
An open movement joint lets rain into the wall every time it pours. That can lead to damp patches, staining and frost damage, all bigger jobs than a reseal.
When to call us in Chelsfield
Using the wrong sealant is another common reason. A stiff, general-purpose sealant cannot cope with a joint that moves a lot, so it pulls away from the edges.
These are the problems we’re asked about most:
- Old sealant gone brittle and cracked
- Movement joints with cracked, split or missing sealant
- Gaps where render, brick and frames meet
- Sealant that has lost its bond to the brick or render
As a London address, Chelsfield can be tricky for parking: let us know about parking bays, permits or a driveway.
Questions to ask before booking
- Whether all the old sealant comes out first
- Whether VAT is included
- What happens if the job turns out different
- What preparation is included
What external mastic looks like in Chelsfield
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For landlords with property near Chelsfield station, outside joints that have cracked can let damp into a rental, so check them between lets. If you live in an older home near Church of St Martin of Tours, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Chelsfield is about 2 miles south-east of Orpington, in Greater London. For external mastic in and around Chelsfield, please call 0345 464 0079 or drop us an email for a quick quote. We cover Greater London from our Crawley base. Our area takes in 764 places across Greater London, large and small. London is on our list too, about 14 miles from Chelsfield.
We work across the BR6 postcode area for external mastic and the streets around it. You will find streets such as Orlestone Gardens, Warren Road and Bucks Cross Road. We also cover the places around Chelsfield: Maypole (1 mile south-east), Bopeep (1 mile south-east), Goddington (1 mile north-west), Well Hill (1 mile east) and Pratt's Bottom (1 mile south-west). Further out, we also cover London (14 miles north-west), Shoreditch (15 miles north-west), Hoxton (15 miles north-west), Whitechapel (14 miles north-west), Stockwell (13 miles north-west) and Wimbledon (15 miles west).
Local landmarks in Chelsfield
In Chelsfield, that means homes and buildings near St Olave's and St Saviour's Grammar School, Five Bells Public House and Harris Academy Orpington, among other places. The closest station to Chelsfield is Chelsfield station, about 0.8 miles west. Well-known places in the area include London Borough of Bromley Museum (1.7 miles north-west) and Orpington Hospital (1.4 miles west). Open spaces near Chelsfield include The Warren and Summer Hill.
Also near Chelsfield
More services for Chelsfield
What we do, step by step
There’s no need to move everything out before we come, just the space around the work. Everything nearby is protected, and the work takes anything from a few hours to several days, depending on the building in most cases. In Chelsfield, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- 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.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Mention any leaks or damp you’ve noticed
- For business premises, tell us about site rules or sign-in
- Clear the area around the work
How to get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we will explain how we’d tackle it. When it suits you, phone 0345 464 0079 or email us.
Advice
What happens if it’s left?
Resealing a run of joints in one go is usually better than patching one at a time. Joints of the same age tend to fail together. In London conversions, one flat’s bathroom is often above another flat’s ceiling, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble for homes in Chelsfield.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed. Call for a quick quote and we will go through it with you.
Why choose Mr Mastic in Chelsfield
- Sanitary silicone with an anti-fungal additive in wet areas
- A sealant colour to suit the surroundings
- Tidy, careful work
- 4.9 on Google from 180+ five-star reviews
Take a look at our cost guide and what customers say.
How the job changes by surface
Concrete and blockwork
Wide joints in concrete need the depth controlling carefully. We size the backing rod to the gap and keep the sealant to the right depth.
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. The movement joint takes that up, so the sealant in it must stay soft and stretchy.