Greater London · England
Selhurst External Mastic
Problem with your movement joints in Selhurst? We remove the old material, prepare the joints and seal them properly, and the work is guaranteed for a year.
- Joints pointed up with cement by mistake
- Rain getting behind render or cladding at a joint
- Leaking joints around cladding and façade panels
What we do, step by step
Good joint work is mostly preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours to a few days, depending on the length of joint and the access. In a London area like Selhurst, 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 checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- Both sides are cleaned back to sound material and primed if needed.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- Tell us about access, such as stairs, a lift or high-level joints
- Plan for the work area to be out of bounds to pets and children
- Tell us about any previous sealing or DIY attempts
Get a quote
To get a quote, phone 0345 464 0079 or email us with the location and a short description of the problem. You’ll have a clear quote before any work starts.
Read more
External mastic for homes and businesses in Selhurst
Ground-floor and low-level joints are straightforward to reach. Where joints are higher up, tell us about the building when you get in touch and we will confirm what access is needed. We’re often asked to deal with brick movement joints where the sealant has split and panel joints letting water in, on joints between brick and frames, façade panels and brickwork movement joints.
London’s terraces and conversions often share walls, gutters and downpipes with their neighbours, so a leaking gutter joint or failed wall joint can affect more than one home. In a converted house in Selhurst, it’s worth checking who is responsible for the outside before booking.
The work is covered for a year after we finish. If there’s a problem with it, please phone 0345 464 0079 or drop us an email.
- Place
- Selhurst (SE25, SE20, CR0)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What affects the cost of external mastic
For a quick quote, just ask. What matters most is:
- Any mould that needs treating
- Any working-time requirements on site
- The number of rooms or windows
- The old material and how stubborn it is
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
Helping us quote
Before you ask for a quote, have a think about:
- Photos by email, if that is easy
- If someone has resealed it before
- The address or postcode of the job
- How many joints, rooms or windows are involved
There’s no standard price list. Instead, your job gets its own clear quote. To get started, phone 0345 464 0079 or send us an email.
Your questions about external mastic in Selhurst
Is parking an issue for external mastic in Selhurst?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Can you help a landlord with a rental near Norwood Junction station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we’ll give you a clear price.
Will there be a smell?
That depends on the sealant. Some products have a noticeable smell, others very little, and any smell fades as they cure.
Will it make a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
How long will you be here?
A typical job takes a few hours for a handful of joints, longer for a whole elevation, including preparation and clearing up. Your quote will say how long we expect yours to take.
Why is there a gap in my brick wall?
Walls move with heat, cold and moisture, so long walls have planned gaps to take that movement. It’s closed with backing rod and a flexible sealant.
Can I add another job to the visit?
Of course. Doing several areas at once is generally more efficient, so mention them when you ask for a quote.
Where is Mr Mastic based?
We work from Crawley. We cover Selhurst and the rest of Greater London.
Places near Selhurst
What else we do in Selhurst
Why it’s worth doing now in Selhurst
Pointing a movement joint with mortar might seem a neat fix, but it locks the joint solid. The movement then cracks the brickwork or render nearby. The correct repair is a flexible sealant with the right backing. 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 Selhurst, 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. We’ll send you a clear quote for the lot.
Why Selhurst clients choose us
- Anti-fungal silicone where joints get wet
- Experience in homes, commercial sites and hotels
- Fully insured
- Rated 4.9 stars on Google
See our cost guide or our reviews.
External mastic in Selhurst: local notes
London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking. With historic houses such as Kingswood House (about 2.2 miles north) nearby, there’s older building stock in the area around Selhurst 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.
Homes close to Church of St Mark include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant. As a London address, Selhurst can be tricky for parking: let us know about parking bays, permits or a driveway.
Selhurst is about 5 miles south-east of Stockwell, in Greater London. Our applicators cover external mastic for homeowners, landlords and businesses in Selhurst and nearby. Our Greater London coverage runs to 764 places, Selhurst among them. For nearby work, see our London page, about 7 miles away.
All of SE25, SE20 and CR0 is covered for external mastic. Streets in the area include Park Road, Court Road and Dixon Road, and we cover them all. Selhurst sits on or near the A213, which makes travel easy. Nearby, we also carry out external mastic in South Norwood (1 mile north), Woodside (1 mile south), Ashburton (1 mile south), Elmers End (1 mile east) and Addiscombe (1 mile south). Larger places within reach include 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 Selhurst
In Selhurst, that means homes and buildings near Harris Academy South Norwood, South Norwood Recreation Ground and The Albion pub. Selhurst 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). Open spaces near Selhurst include Duppas Hill and Dulwich Upper Wood.
Signs you need external mastic in Selhurst
Sometimes a movement joint was filled with mortar or a rigid filler by mistake. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Most people get in touch after spotting one of these:
- Panel joints letting water in
- Weathered mastic that no longer stretches
- Brick movement joints where the sealant has split
- Sealant that has lost its bond to the brick or render
Letting a property close to Norwood Junction station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Comparing quotes
- Is VAT in the price?
- How long the guarantee is
- Who does the work, and how experienced they are
- What product goes in the joint
Landlords, agents and businesses in Selhurst
In hotels, rooms out of use cost money, so we plan the work room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
We regularly work with letting and managing agents. Tell us the address, the job and how access works.
Can I do it myself?
A DIY attempt does not rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
What we cannot put right
Honest advice matters more to us than a booking, so here’s what new sealant won’t do:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracks in the bricks or render themselves, away from the joints
- Structural movement, which needs a surveyor or engineer
If you are not sure, just phone 0345 464 0079 or email us and we will give you a straight answer before you book.
What we seal
- Brickwork movement joints
- Copings & trims
- Façade panels
- Concrete & block
- Joints between brick and frames
- Render & cladding joints