Greater London · England
External Mastic in The Wrythe
Specialist external mastic for The Wrythe: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Sealant that has lost its bond to the brick or render
- Joints pointed up with cement by mistake
- Damp patches traced to an open external joint
What affects the cost of external mastic
We do not publish a price list, because no two jobs are the same. The quote depends on:
- Working hours on commercial sites
- Whether old sealant or filler has to be cut out
- How much there is to do
- Any mould that needs treating
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you are not sure whether it needs doing, phone 0345 464 0079 or drop us an email for an honest opinion and a quote.
What to tell us for a quote
There’s no need for technical detail. It helps if you can tell us:
- Whether it has been sealed before
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
- The address or postcode of the job
Call for a quick quote, or send an email if you’d rather. Tell us about the joints that need doing and we will talk you through the work.
External mastic in The Wrythe, done properly
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we will confirm what’s needed to reach them safely. We work on joints between brick and frames, brickwork movement joints and render & cladding joints, and common reasons people get in touch are failed seals between different materials and weeds or debris growing in open joints.
Modern London flats rely on sealed movement joints and cladding joints. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall, and both kinds of building are found across London.
Our work is backed for twelve months.
- Place
- The Wrythe (SM5, SM6, SM1)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quote
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
For landlords and businesses
We also work for property managers and facilities teams. We can quote a run of properties together.
Hotels need rooms back in use, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.
The process
Good joint work is mostly preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. In total, it usually takes anything from a few hours to several days, depending on the building. In The Wrythe, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- First we look over the joints with you, agree which to renew and talk through access.
- Old sealant and any debris are cut and raked out.
- We clean both faces of the joint and prime them where the product calls for it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Getting ready for the visit
- Mention if the joints have been sealed before
- For indoor joints, keep the area dry beforehand if you can
- Mention any tricky access
Ask for a quote
There’s no standard price list. Instead, we give you a clear price for your job. To get started, call 0345 464 0079 or email us.
Related advice
Places near The Wrythe
More services for The Wrythe
External mastic in The Wrythe: local notes
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. London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts.
Letting a property close to Carshalton station? Then split movement joints are easy to miss on a rental until damp shows inside. Managing a site like Victor Seymour Infants' School? Then its movement joints, gutters and trims need looking after like any other building’s.
The Wrythe is about 7 miles south of Stockwell, in Greater London. Whether you are in the middle of The Wrythe or further out, external mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Across Greater London, we cover 764 places, and The Wrythe is one of them. London is on our list too, about 9 miles from The Wrythe.
Work in SM5, SM6 and SM1 works the same way as everywhere else we cover. Local streets include Elm Road, Byne Road and Mill Lane, and we cover them all. Other places close to The Wrythe include Carshalton (1 mile south), Wallington (1 mile south-east), Rosehill (1 mile north-west), St Helier (1 mile north-west) and Benhilton (1 mile west). Further out, we also cover London (9 miles north), City of Westminster (10 miles north), Marylebone (10 miles north), Kensington (9 miles north), St Pancras (11 miles north) and Shoreditch (11 miles north).
Near you in The Wrythe
Typical jobs here are in homes near Carshalton Park, The Railway Tavern and Carshalton High School for Girls, among other places. There’s a railway station in The Wrythe itself: Carshalton station. Nearby you will also find Centrale Croydon (2.7 miles east) and Honeywood Museum (0.6 miles south). Not far away are The Spinney Local Nature Reserve and Duppas Hill.
Common questions in The Wrythe
Is parking a problem for a job in The Wrythe?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
I let a flat near Carshalton station. Can you help?
Yes, landlords and agents are among the people we work for. You can phone 0345 464 0079 or send us an email with the details for a clear quote.
Can I do it myself?
That depends on the joint. 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.
How long will you be here?
Typically it takes a few hours for a handful of joints, longer for a whole elevation. Bigger jobs take longer, and we’ll tell you how long to expect.
What do you put in the joint?
Each joint gets the product that suits it. Where it moves, gets wet or faces the weather makes a difference, and we’ll explain our choice.
What information do you need?
Let us know what needs doing and where, plus photos if you have them. If we need more, we’ll ask.
Do you hold any approvals?
Yes. We hold ARBOMaster approved applicator status and we are fully insured too.
How long before the joint can be used?
Most sealants are touch-dry well before they’re fully cured. We’ll tell you how long to leave the joint before we leave.
When it is not the sealant
We’d rather tell you now than do work that won’t last, so here’s what sealant can’t put right:
- Movement that’s more than a sealant joint can take
- Damp that isn’t coming from the joint
- Walls that need new movement joints cut into them
If you’re not sure, just ring 0345 464 0079 or drop us an email and we’ll give you a straight answer.
Where we work in The Wrythe
- Concrete & block
- Brickwork movement joints
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Copings & trims
How the job changes by surface
Joints between dissimilar materials
Wherever two materials meet, they move differently. A flexible sealant bridges the two.
Cladding and façade panels
Panel systems often rely on sealant between and around the panels. We reseal them with a sealant suited to the panel material.
What happens if it’s left?
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. Converted houses in London often have a bathroom above someone else’s living room, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler.
The cost depends on the amount of work, how much old material has to come out and access to the work. You will have a clear quote before any work starts.
What you get with us
- Fully insured
- Any old sealant cut out fully, not covered over
- 4.9 on Google from 180+ five-star reviews
- Anti-fungal silicone where joints get wet
See how sealant jobs are priced and our reviews.
Common problems we fix in The Wrythe
Weeds, moss and debris in a joint are a sign the sealant has gone. Roots and dirt hold water against the wall and make things worse.
Keep an eye out for any of the following:
- Damp patches traced to an open external joint
- Cracked joints where brick meets render or frames
- Hard, crazed mastic that has stopped moving
- Plants rooting in failed movement joints
For an older house near a landmark such as Bishop Andrewes Church, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Comparing quotes
- Whether all the old sealant comes out first
- How the colour is chosen
- How hidden problems are handled
- How the joint is cleaned and prepared