Greater London · England
South Norwood External Mastic
External mastic for South Norwood and the surrounding area: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Plants rooting in failed movement joints
- Hard, crazed mastic that has stopped moving
- Gaps where render, brick and frames meet
External mastic in South Norwood
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render so the line blends in. Common call-outs are for leaking joints around cladding and façade panels and joints with sealant missing in places, across façade panels, render & cladding joints and joints between brick and frames.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall, and both kinds of building are found across London.
Every job is covered by our 12-month guarantee.
- Where
- South Norwood (SE25, SE20, CR0)
- Wider area
- Greater London
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
For landlords and businesses
For anyone letting property in or around South Norwood, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs, and photos by email help.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
Should I try it myself first?
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
What happens on the day
When we arrive, we start by going over the job with you. We protect the surfaces around the joints before work begins. The work normally takes a few hours for a handful of joints, longer for a whole elevation. In a London area like South Norwood, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Before we arrive
- Let us know if you’ve seen damp or leaks
- Move anything stored near the joints
- Plan for the work area to be out of bounds to pets and children
How to get a quote
For a quote, ring 0345 464 0079 or email us and tell us where the job is and what the problem looks like. You’ll have a clear quote before any work starts.
Read more
Walls and rooflines in South Norwood
In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts. With historic houses such as Kingswood House (about 2.2 miles north) nearby, there’s older building stock in the area around South Norwood as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth.
South Norwood is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. For an older house near a landmark such as Church of St Mark, the joints between older walls, newer extensions and the roofline need a sealant that can move. If you look after a building such as St Mark's Church of England Primary Academy, its movement joints, gutters and trims need looking after like any other building’s.
South Norwood is about 5 miles south-east of Stockwell, in Greater London. For external mastic in and around South Norwood, it’s easy to get a quote: please call 0345 464 0079 or email us. We cover Greater London from our Crawley base, South Norwood included. South Norwood is one of 764 places in Greater London where we work for external mastic. For nearby work, see our London page.
Every address in SE25, SE20 and CR0 is covered for external mastic, from the main roads to the quietest streets. Local streets include Park Road, Court Road and Dixon Road, all of which we cover. South Norwood is on the A213, which makes it straightforward to reach with everything needed for external mastic. Neighbouring places we cover for external mastic include Selhurst (1 mile north), Woodside (1 mile south), Ashburton (1 mile south), Elmers End (1 mile east) and Addiscombe (1 mile south). Further out, we also cover London (7 miles north), City of Westminster (9 miles north-west), Marylebone (9 miles north), Kensington (9 miles north-west), St Pancras (9 miles north) and Shoreditch (9 miles north).
What’s near South Norwood
We work in homes and buildings around The Albion pub, South Norwood Recreation Ground and Harris Academy South Norwood, among other places. South Norwood has its own railway station: Norwood Junction station. Other landmarks nearby include Croydon University Hospital (1.7 miles south-west) and Crystal Palace Museum (1.4 miles north). For a walk, there’s Dulwich Upper Wood and Duppas Hill.
Honest limits
A few problems are outside what sealant work can do:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracking across the wall rather than at a joint
- Walls that need new movement joints cut into them
If you’re not sure, just ring 0345 464 0079 or send us an email and we will give you a straight answer.
Joints and surfaces we work on
- Render & cladding joints
- Façade panels
- Copings & trims
- Concrete & block
- Brickwork movement joints
- Joints between brick and frames
South Norwood: your questions answered
Is South Norwood in your area for external mastic?
Yes. Our work covers London and the South East, and South Norwood is part of that. Just phone 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear quote.
I let a flat near Norwood Junction station. Can you help?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Will you leave a mess?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
When is the sealant fully cured?
It depends on the product and the conditions. Before we leave, we will tell you the cure time.
What’s an expansion joint in brickwork?
A vertical gap in a long brick wall is usually a movement joint. It lets the bricks expand without cracking and needs a flexible seal, not mortar.
Which products do you use?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
Are you fully insured?
Yes, we’re fully insured.
Can I add another job to the visit?
Yes. Just list everything you need.
Towns and villages near South Norwood
More services for South Norwood
What affects the quote in South Norwood
Jobs vary more than people expect. What affects the quote:
- The number of rooms or windows
- Mould in or behind the old joints
- Which sealant suits the joint
- Whether the work is at height
No two jobs are quite the same, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all make a difference, and we will explain the quote if you ask.
What we need to know
To make quoting easier, let us know:
- The type of property
- Pictures of the joints, sent by email
- Whether it has been sealed before
- Access, such as stairs, a lift or height
For a quick quote, get us on the phone, or email us if that is easier. Tell us about the joints that need doing and we’ll explain what’s involved.
Leave it or put it right?
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. Too stiff a sealant can pull at the edges and break them. 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. Dealing with it early is far simpler.
Instead of a standard rate, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
What you get with us
- We leave the area clean and tidy
- A 12-month guarantee on all work
- Old sealant always removed completely
- Full insurance on every job
Read how sealant jobs are priced and our reviews.
Keeping the joints in good condition
Simple care keeps the joints in good condition. Our advice:
- Check external joints each spring
- Act on the first splits you see
- Keep soil, plants and ivy away from the joints
- Ask before painting over external sealant
Only paint over the joint if we have confirmed the sealant can take paint. Many exterior sealants aren’t designed to be painted and spoil the finish.
If you can see gaps, plants or bare sections in a joint, have it checked. Early work is quicker and leaves a better finish.