Greater London · England
External Mastic in North Cheam
Specialist external mastic for North Cheam: careful preparation, the right product and tidy work. Call for a quick quote.
- Cracked joints where brick meets render or frames
- Sealant that has lost its bond to the brick or render
- Old sealant gone brittle and cracked
About our external mastic in North Cheam
Joints in render and cladding are easy to overlook until a damp patch appears. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product in a matching colour. We’re often asked to deal with cracked joints where brick meets render or frames and sealant pulling away from one side of the joint, across façade panels, copings & trims and concrete & block.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. In North Cheam, joints up high may need ladders or other access, which is worth talking through when you book.
There’s a 12-month guarantee on every job, whatever its size.
- Place
- North Cheam (SM3, KT4, SM1)
- Region
- Greater London
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Should I try it myself first?
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
Also near North Cheam
More services for North Cheam
External mastic in North Cheam: local notes
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. With historic houses such as Nonsuch Mansion (about 1 mile south) nearby, there’s older building stock in the area around North Cheam 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.
Managing a site like Cheam Park Farm Primary Academy? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. For landlords with property near West Sutton station, outside joints that have cracked can let damp into a rental, so check them between lets.
North Cheam is about 3 miles north-east of Epsom, in Greater London. If you need external mastic in North Cheam, it’s easy to get a quote: please phone 0345 464 0079 or send us an email. We are based in Crawley and cover Greater London, North Cheam included. North Cheam is one of 764 towns and villages in Greater London we cover for external mastic. For nearby work, see our London page.
We work across the SM3, KT4 and SM1 postcode area for external mastic. External mastic is available to properties on Glyn Road, Covey Road and Lloyd Road and the roads around them. Close by, we work in Cuddington (1 mile south-west), Lower Morden (1 mile north), Sutton Common (1 mile north-east), Stoneleigh (1 mile south-west) and Morden (2 miles north). Within a short drive, we also cover London (10 miles north-east), City of Westminster (10 miles north), Marylebone (11 miles north), Kensington (9 miles north), St Pancras (12 miles north) and Shoreditch (12 miles north-east).
Local landmarks in North Cheam
Typical jobs here are in homes near The Nonsuch Inn, Sutton College of Learning for Adults and Nonsuch Park. North Cheam’s nearest station is West Sutton station, roughly 0.8 miles south-east. A little further out are Chessington Castle Hill (3.2 miles west) and St. Anthony's Hospital (0.6 miles north). Not far away are Henman Hill and Derwent Floodwash.
How we quote for external mastic
The quote reflects the job in front of us. We take into account:
- Working hours on commercial sites
- Access and height
- The size of the job
- How many rooms, windows or areas are involved
We do not show prices on the website, because the cost depends so much on the job itself. Call for a quick quote.
What we need to know
Before you ask for a quote, have a think about:
- The address or postcode of the job
- Photos by email, if that is easy
- Whether it has been sealed before
- How many joints, rooms or windows are involved
Need a quote? Please ring 0345 464 0079 or drop us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
What the job involves on each surface
Joints between dissimilar materials
Wherever two materials meet, they move differently. A flexible sealant bridges the two so neither cracks the other.
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. We reseal their joints with backing rod and a flexible product.
When to call us in North Cheam
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. The joint can’t move, so the wall cracks somewhere else instead.
Signs it’s time to call us include:
- Sealant pulling away from one side of the joint
- Old sealant gone brittle and cracked
- Joints pointed up with cement by mistake
- Water getting into walls through failed joints
If you live in an older home near St Oswald Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
What to look for in a quote
- When the joint can take water or movement
- Whether they’re fully insured
- How the colour is chosen
- Whether VAT is included
What we do, step by step
Before we leave, we go over the finished joints with you. The visit itself normally takes anything from a few hours to several days, depending on the building, depending on the amount of work. In a London area like North Cheam, 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.
- Old sealant and any debris are cut and raked out.
- The joint faces are cleaned and primed where the sealant needs it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- Tell us if parking is tricky
- Tell us about any previous sealing or DIY attempts
- Mention any tricky access
Get a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll talk you through what we’d do. Whenever you are ready, ring 0345 464 0079 or drop us an email.
Advice
When something else is needed
We won’t take on work that will not last, so here’s what sealant can’t put right:
- Render that is blown, hollow or coming away
- Cracked brickwork or render that needs a builder or plasterer
- Structural movement, which needs a surveyor or engineer
If you are not sure, just ring 0345 464 0079 or drop us an email and we’ll give you a straight answer.
Joints and surfaces we work on
- Render & cladding joints
- Concrete & block
- Façade panels
- Brickwork movement joints
- Copings & trims
- Joints between brick and frames
Your questions about external mastic in North Cheam
Can you help a landlord with a rental near West Sutton station?
Yes, we work for letting agents and landlords. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Can parking be tricky for a visit in North Cheam?
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.
Do I need to be at home?
That depends on where the joints are. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
How long does external mastic last?
That varies with the weather the wall faces, how much it moves and the sealant used. Treat it as a maintenance item and look at it yearly and reseal when it splits.
Do you work for hotels and businesses?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
Do you use backing rod?
That’s backing rod, a closed-cell foam. It stops the sealant going in too deep and bonding to three sides.
Should I try DIY first?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. If it doesn’t work out, we can redo it.
Do you take out the old sealant first?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
How to look after the new joints
After the cure time, these simple habits help:
- Check the sealant is paintable before painting near it
- Avoid pressure-washing directly into sealant joints
- Get split or bare joints resealed while the damage is small
- Keep water from gutters off the wall
Keep the joints clear of soil, plants and climbing growth. Damp material against the sealant shortens its life.
Once a joint cannot move, the wall finds another way, often as cracks near the joint. Resealing it early helps prevent that.