Greater London · England
External & façade joints in Morden, Greater London
External mastic for Morden, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Sealant pulling away from one side of the joint
- Movement joints filled with mortar instead of sealant
- Gaps where render, brick and frames meet
External mastic in Morden, done properly
A movement joint is only as good as its depth. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, so it bonds to the two sides only and can stretch. If you’re dealing with failed seals between different materials and rain getting behind render or cladding at a joint, we can put it right, whatever the surface.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Morden, tell us how high the joints are and how to reach the back of the building.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Location
- Morden (SM4, SM3, SW20)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What we do, step by step
There isn’t much for you to do on the day. Point us to the joints and we’ll get on with it. The job generally takes a few hours to a few days, depending on the length of joint and the access from start to finish. In Morden, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
How to prepare
- Tell us about any water getting in
- Clear the area around the work
- Mention if the joints have been sealed before
Ask for a quote
We quote each job on its own, so start by telling us what you need. Just phone 0345 464 0079 or send us an email with the details and send photos if you have them.
Advice
Different surfaces, different methods
Copings and trims
Coping joints that leak let water straight down into the wall. Resealing them is a small job that protects a lot.
Brickwork movement joints
Clay brickwork grows slightly over its life and moves with the weather. That movement goes into the joint, so the sealant in it must stay soft and stretchy.
Quotes for external mastic in Morden
You’ll get a clear quote before work begins. It takes into account:
- Whether the work is at height
- Working hours on commercial sites
- The size of the job
- How many areas need sealing
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. We take all of that into account in your quote.
What to tell us for a quote
You don’t need to know the technical terms. Just tell us:
- How many joints, rooms or windows are involved
- Pictures of the joints, sent by email
- Whether it’s a home or a business
- Any access issues, like height or stairs
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.
Why it’s worth doing now in Morden
Sealing over the top of old mastic doesn’t hold for long. The new layer can’t bond properly to old, weathered material, so we always take the old sealant out. 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.
What you get with us
- Tidy, careful work
- Anti-fungal silicone where joints get wet
- Fully insured
- Any old sealant cut out fully, not covered over
Read our cost guide and customer reviews.
What external mastic looks like in Morden
The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts.
If you live in an older home near St Lawrence Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. Morden is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Morden is about 2 miles south of Wimbledon, in Greater London. Homes, rented property, offices and hotels in Morden is covered for external mastic, old or new, large or small. Every job comes with our one-year guarantee. We cover 764 towns and villages across Greater London, large and small. For nearby work, see our London page.
Postcode districts we cover here for external mastic: SM4, SM3 and SW20. External mastic is available to properties on London Road, Epsom Road and Holne Chase. Morden is on the B279, so it’s easy for us to get to with everything needed for external mastic. We also cover the places around Morden: Lower Morden (1 mile south-west), Sutton Common (1 mile south-east), North Cheam (2 miles south), Worcester Park (2 miles south-west) and Stoneleigh (3 miles south-west). Further out, we also cover London (9 miles north-east), City of Westminster (9 miles north), Marylebone (9 miles north), Kensington (7 miles north), St Pancras (10 miles north-east) and Shoreditch (11 miles north-east).
Near you in Morden
Around Morden, our work takes us to homes and buildings near Lord Nelson pub, Glenthorne High School and Cannon Hill Common, among other places. There’s a railway station in Morden itself: St Helier station. A little further out are St. Anthony's Hospital (1 mile south-west) and Chessington Castle Hill (4.3 miles south-west). Open spaces near Morden include Henman Hill and Morden Park (park).
Morden questions
Is parking a problem for a job in Morden?
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.
Do you work for landlords with property near St Helier station?
Yes. We work for landlords and letting agents as well as householders, and several properties can go on one quote. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we’ll send you a clear quote.
Can you match the colour of my brickwork?
The sealant colour is picked to suit the wall so the joint blends in. Exterior sealants come in a good range of colours.
Is it OK to fill a movement joint with cement?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose. A flexible sealant is the right fill.
Is there any odour?
Possibly a little. It fades as the sealant cures, and ventilation helps.
Why do you put foam in the joint first?
That’s backing rod, a closed-cell foam. It stops the sealant going in too deep and bonding to three sides, which would stop it stretching.
Are you insured?
Yes. We are fully insured for every job we do.
Can new sealant go over the old?
No. New silicone will not bond to old silicone, and it traps any mould or water underneath. It all has to come out first.
Common problems we fix in Morden
The wrong product in a moving joint is a classic cause. A stiff, general-purpose sealant can’t cope with a joint that moves a lot, and it tears off the sides.
These are the problems we’re asked about most:
- Moss and dirt in joints with no sealant left
- Old sealant gone brittle and cracked
- Damp patches traced to an open external joint
- Joints where the bead has come unstuck
If you look after a building such as Morden Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Questions to ask before booking
- What guarantee comes with the work
- What the cure time is
- What product goes in the joint
- Is the old sealant removed completely?
Other services in Morden
Landlord and commercial work in Morden
For anyone letting property in or around Morden, jobs at different addresses can go on one quote. Send us the addresses and the work at each.
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
Honest limits
We will not take on work that won’t last, so here’s what sealant can’t put right:
- Damp that isn’t coming from the joint
- Structural movement, which needs a surveyor or engineer
- Cracked brickwork or render that needs a builder or plasterer
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think.
What we seal
- Render & cladding joints
- Concrete & block
- Brickwork movement joints
- Joints between brick and frames
- Façade panels
- Copings & trims