Greater London · England
External & façade joints in South Bermondsey, Greater London
External mastic in South Bermondsey from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Joints with sealant missing in places
- Failed sealant between panels on a façade
- Moss and dirt in joints with no sealant left
Different surfaces, different methods
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
Render joints
Render is weaker at the surface than brick, so a low-modulus sealant is kinder to the joint edges. Priming is done where the sealant calls for it.
External mastic in South Bermondsey, done properly
A movement joint is a deliberate break that lets a wall expand and contract. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. If you have rigid filler in a joint that should flex and movement joints with cracked, split or missing sealant, we can help, whatever the surface.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
The work is covered for a year after we finish. If there’s a problem with it, please call 0345 464 0079 or email us.
- Place
- South Bermondsey (SE16, SE15, SE1)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Looking after it afterwards
Good habits help new joints last longer. Our tips:
- Check external joints each spring
- Get split or bare joints resealed while the damage is small
- Tell anyone working on the walls about the movement joints
- Never let anyone fill a movement joint with mortar
Have a quick look at the joints each spring. Watch for splits, edges coming away or growth in the joint.
If you can see gaps, plants or bare sections in a joint, have it checked. Early work is quicker and leaves a better finish.
Leave it or put it right?
Pointing a movement joint with mortar might seem a neat fix, but it stops the joint moving. The wall then cracks somewhere else. The correct repair is a flexible sealant with the right backing. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
What you get with us
- Rated 4.9 stars on Google
- An ARBOMaster approved applicator
- White, clear, grey or coloured to suit, where the product allows
- Anti-fungal silicone where joints get wet
Take a look at our cost guide and what customers say.
How we quote for external mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- Access and height
- The number and length of the joints
- Any mould that needs treating
- When we can work, for business premises
What it costs 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 we need to know
Photos help, but a description is a good start. Please mention:
- Pictures of the joints, sent by email
- Where the job is, and your postcode
- How we’d reach the joints
- What’s wrong with the joints now
It all starts with a short chat. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. Whenever you’re ready, call 0345 464 0079 or send us an email.
Questions from South Bermondsey
Can you help a landlord with a rental near South Bermondsey station?
Yes. We work for landlords and agents as well as homeowners. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we will send you a clear quote.
Is South Bermondsey in your area for external mastic?
Yes. We work across London and the South East, and South Bermondsey is part of that. You can ring 0345 464 0079 or email us and let us know what needs doing, and we’ll send you a clear quote.
Can you quote for more than one area?
Yes, and it often makes sense. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. Once we have agreed the job, you don’t need to watch us work.
Are you fully insured?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
What do you put in the joint?
We choose the sealant for the joint, not the other way round. Where it moves, gets wet or faces the weather makes a difference, and we’ll tell you what we are using.
Should I try DIY first?
It depends on the job. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Signs you need external mastic in South Bermondsey
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it cannot stretch and tears as soon as the joint widens.
These are the problems we’re asked about most:
- Hard, crazed mastic that has stopped moving
- Sealant pulling away from one side of the joint
- Rain getting behind render or cladding at a joint
- Failed seals between different materials
For landlords with property near South Bermondsey station, outside joints that have cracked can let damp into a rental, so check them between lets.
What your quote should include
- What guarantee comes with the work
- What product goes in the joint
- How much experience the applicator has
- Whether they seal over old material or remove it
What we do, step by step
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The work itself 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. Mention any building rules, key holders or managing agents when you book.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Plan for the work area to be out of bounds to pets and children
- Move anything stored near the joints
- Let us know if you’ve seen damp or leaks
Get a quote
Need a quote? Please call 0345 464 0079 or send us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Related advice
Should I try it myself first?
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
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.
Towns and villages near South Bermondsey
More services for South Bermondsey
Walls and rooflines in South Bermondsey
Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. With historic houses such as Mansion House (about 2.3 miles north-west) nearby, there’s older building stock in the area around South Bermondsey as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
If you live in an older home near Church of St Augustine, the joints between older walls, newer extensions and the roofline need a sealant that can move. South Bermondsey is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
South Bermondsey is about 2 miles north-west of New Cross, in Greater London. South Bermondsey gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our Greater London coverage runs to 764 places, South Bermondsey among them.
Work in SE16, SE15 and SE1 is quoted and booked the same way as anywhere else. External mastic is available to properties on Tenda Road, Rolls Road and Simms Road. South Bermondsey is on the A2208, which makes it straightforward to reach. We also cover the places around South Bermondsey: Surrey Canal (1 mile east), Surrey Quays (1 mile north-east), Bermondsey (1 mile north-west), Peckham (1 mile south) and Rotherhithe (1 mile north-east). Larger places within reach include City of Westminster (4 miles north-west), Marylebone (4 miles north-west), Kensington (6 miles west), St Pancras (4 miles north-west), Shoreditch (3 miles north) and Walthamstow (7 miles north).
Landmarks near South Bermondsey
Typical jobs here are in homes near The Kentish Drovers Public House, Paterson Park and City of London Academy, among other places. There’s a railway station in South Bermondsey itself: South Bermondsey station. Nearby you’ll also find New Cross Hospital (0.6 miles south-east) and Surrey Quays Shopping Centre (0.8 miles north-east). Not far away are St. James's Park Lake and Tower Hill.