Greater London · England
External Mastic in Brasted Chart
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Brasted Chart and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Old sealant gone brittle and cracked
- Failed seals between different materials
- Joints pointed up with cement by mistake
What happens on the day
A visit follows a simple pattern: we check the joints, protect the area around them, carry out the job and tidy away. It normally takes a few hours to a few days, depending on the length of joint and the access. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- 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.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Keep children and pets away from the work area
- Tell us if parking is tricky
- Mention any leaks or damp you’ve noticed
Getting a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints.
Read more
About our external mastic in Brasted Chart
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant in a colour to suit. We’re often asked to deal with old sealant gone brittle and cracked and damp patches traced to an open external joint, on concrete & block, façade panels and render & cladding joints.
Modern London flats rely on sealed movement joints and cladding joints. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall.
You get a 12-month guarantee, the same in Brasted Chart as everywhere else we work.
- Where
- Brasted Chart (TN16)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
How the job changes by surface
Brickwork movement joints
Brick movement joints are often mistaken for a missing mortar line. If that’s happened, we rake it out and reseal it properly.
Cladding and façade panels
Cladding and façade panels are generally separated by sealed joints. Each joint gets a sealant that suits the panel and its movement.
What affects the cost of external mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- How many areas need sealing
- The amount of work
- The old material and how stubborn it is
- Any mould that needs treating
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
What to tell us for a quote
What to tell us when you ask for a quote:
- Roughly how big the job is
- If it’s domestic, commercial or a hotel
- Any access issues, like height or stairs
- Whether it has been sealed before
We quote each job on its own, so the first step is telling us about yours. Just call 0345 464 0079 or drop us an email with the details.
External mastic in Brasted Chart: local notes
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. With historic houses such as Quebec House (about 1.2 miles west) nearby, there’s older building stock in the area around Brasted Chart as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
Rented homes near Sevenoaks station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies. Homes close to Church of St Martin include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
Brasted Chart is about 4 miles west of Sevenoaks, in Greater London. Whether you’re in the middle of Brasted Chart or further out, we cover external mastic for every kind of property, from flats and houses to offices and hotels. We cover 764 towns and villages across Greater London. There’s also a page for Crawley, roughly 16 miles from Brasted Chart.
Work in TN16 works the same way as everywhere else we cover. That includes homes and businesses on Chart Lane and Pipers Lane and the roads around them. Close by, we work in Brasted (1 mile north), Toy's Hill (1 mile south), Sundridge (1 mile north-east), Ide Hill (2 miles south-east) and Goathurst Common (2 miles south-east). We also work in nearby towns such as Orpington (8 miles north), Thornton Heath (13 miles north-west), Croydon (11 miles north-west), Streatham (15 miles north-west), Bromley (10 miles north) and West Norwood (14 miles north-west).
Around Brasted Chart
The nearest railway station is Sevenoaks station, roughly 3.6 miles east. Well-known places in the area include Tandridge Priory (3.3 miles west). For a walk, there’s Betsom's Hill and Dryhill Nature Reserve.
Places near Brasted Chart
Also in Brasted Chart
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
FAQs for Brasted Chart
Is Brasted Chart in your area for external mastic?
Yes, Brasted Chart is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job.
Is parking an issue for external mastic in Brasted Chart?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Can landlords and businesses book you?
Yes, we do. We work in homes, commercial premises and hotels, and we’re fully insured.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status, and we are fully insured.
Can you reach joints on upper floors?
That depends on the building and the joints. Where joints can be reached safely, we will do them. Give us some details and we will confirm the access.
Do you have insurance?
Yes. Mr Mastic is fully insured.
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 reseal when it splits.
Can you seal joints between render and window frames?
Yes. Materials like render, brick, metal and uPVC all move differently, so the joint between them must be flexible. The sealant is matched to both sides.
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy. Several properties can go on one quote.
Landlords and letting agents in Brasted Chart can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order.
Why it’s worth doing now in Brasted Chart
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That matters on brick, render and concrete, which can be weaker at the face. A stiffer product can damage the joint edge as it fails. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Dealing with it early is far simpler.
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. You’ll know the price before we begin.
Why us?
- Every job guaranteed for a year
- A choice of colours where the product allows
- Anti-fungal silicone where joints get wet
- We leave the area clean and tidy
Read what affects the cost and what customers say.
Do you need external mastic in Brasted Chart?
Using the wrong sealant is another common reason. A high-modulus or general-purpose sealant can be too rigid for a busy joint, and it tears off the sides.
Any of these means the joints need attention:
- Moss and dirt in joints with no sealant left
- Sealant pulling away from one side of the joint
- Rigid filler in a joint that should flex
- Leaking joints around cladding and façade panels
Brasted Chart is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Questions to ask before booking
- How the surfaces are prepared before sealing
- What happens if they find a problem under the old sealant
- Who turns up on the day
- Which colour the sealant will be