Greater London · England
New Addington External Mastic
External mastic across New Addington and nearby, with old sealant always removed completely and a 12-month guarantee.
- Rigid filler in a joint that should flex
- Weeds or debris growing in open joints
- Cracked joints where brick meets render or frames
External mastic for homes and businesses in New Addington
A movement joint is a deliberate break that lets a wall expand and contract. The sealant in it has to stretch and squeeze for years, and when it fails, the wall takes the strain and water finds a way in. If you have movement joints with cracked, split or missing sealant and panel joints letting water in, we can help, on concrete & block, façade panels and copings & trims alike.
In London terraces and converted houses, gutters and walls are often shared with the house next door, so a leaking gutter joint or failed wall joint can affect more than one home. In a converted house in New Addington, it’s worth checking who is responsible for the outside before booking.
Big or small, you get the same 12-month guarantee in New Addington and across Greater London.
- Where
- New Addington (CR0, CR9)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What sealant work cannot fix
Sealant isn’t the answer to every problem, and we will tell you before any work starts. Sealant will not put right:
- Subsidence or other structural problems
- Cutting new joints into brickwork, which is building work rather than sealant work
- Rising or penetrating damp from elsewhere in the wall
If in doubt, call 0345 464 0079 or email us and we will say what we think.
What we seal
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Joints between brick and frames
- Render & cladding joints
- Façade panels
The process
Most of a good job is in the preparation, and we don’t rush it. Joints are cleaned back and dried before anything new goes in. In total, it normally takes a few hours for a handful of joints, longer for a whole elevation. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- 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
- Try not to wet indoor joints just before the visit
- Keep children and pets away from the work area
- Let us know about stairs, lifts or work at height
How to get a quote
Getting a quote is simple: let us know what needs doing and where. A few photos by email make the job easier to understand.
Advice
Why act early in New Addington
The longer a joint stays open, the more water the wall takes in. In cold weather, frost can damage wet brick and render around the joint, so the problem grows beyond the joint itself. In a flat in New Addington, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed. Call for a quick quote and we will explain what it covers.
Why choose Mr Mastic in New Addington
- Arbo and Everbuild products
- Old sealant always removed completely
- White, clear, grey or another colour, product permitting
- We agree the colour with you first
Take a look at our cost guide or what customers say.
Signs you need external mastic in New Addington
A lot of failed joints come down to preparation: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
Common reasons people contact us are:
- Joints where the bead has come unstuck
- Brick movement joints where the sealant has split
- Plants rooting in failed movement joints
- Failed seals between different materials
For an older house near a landmark such as St Edward King and Confessor, an extension built onto an older house moves differently, and the joint between them takes the strain.
Before you book anyone
- How hidden problems are handled
- How long the guarantee is
- Whether you can choose the colour
- Whether they seal over old material or remove it
Quotes for external mastic in New Addington
We quote each job individually. This is what makes a difference:
- Any mould that needs treating
- How easy the joints are to reach
- Which sealant suits the joint
- When we can work, for business premises
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. You will know the price before we begin.
What to tell us for a quote
To make quoting easier, please include:
- The type of property
- Any access issues, like height or stairs
- The rough size of the job
- What’s wrong with the joints now
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. Whenever you are ready, ring 0345 464 0079 or email us.
Aftercare tips
After the cure time, these simple habits help:
- Wash walls gently around the sealant
- Keep water from gutters off the wall
- Walk round the building once a year and look at the joints
- Leave the joints unpainted unless we’ve said otherwise
Avoid pressure-washing straight into the joints. High-pressure water can lift the edges over time.
A joint that has stopped moving pushes the movement elsewhere, normally as cracking in the brickwork or render nearby. Resealing it early helps prevent that.
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy. We can quote for more than one property at once.
Hotels need rooms back in use, so we plan the work room by room around your bookings where we can. We have worked in hotels as well as homes and businesses.
New Addington questions
I let a flat near Hayes (Kent) station. Can you help?
Yes, we work for letting agents and landlords. You can call 0345 464 0079 or send us an email with the address and a few details, and we will give you a fixed price before work begins.
Do you cover New Addington for external mastic?
Yes. We work across London and the South East, and New Addington is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job.
What should I tell you?
Where the job is, what the problem is and roughly how big it is. Photos by email help too.
Is there a guarantee?
Yes. Each job is guaranteed for twelve months.
Will you leave a mess?
We keep the work tidy. Nearby surfaces are protected.
Are you an approved applicator?
Yes. Mr Mastic is an ARBOMaster approved applicator, and we’re fully insured.
Are you insured?
Yes. Full insurance covers our work.
What is a movement joint?
A vertical gap in a long brick wall is usually a movement joint. It lets the bricks expand without cracking, and it should be sealed with a flexible sealant.
External mastic in New Addington: local notes
With historic houses such as Addington Palace (about 1.5 miles north-west) nearby, there’s older building stock in the area around New Addington as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you look after a building such as Rowdown Primary School, larger buildings have long runs of movement joint that eventually need resealing. Rented homes near Hayes (Kent) station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
New Addington is about 4 miles south-east of Croydon, in Greater London. Homes, rented property, offices and hotels in New Addington can book us for external mastic. Every job comes with our 12-month guarantee. 764 places in Greater London are on our list. Our London page covers work nearby (11 miles or so).
Work in CR0 and CR9 is quoted and booked the same way as anywhere else. Whether your property is on Bothwell Road, Windham Avenue and Gascoigne Road or anywhere close by, our applicators can take on the job. Nearby, we also carry out external mastic in Forestdale (1 mile west), Fickleshole (1 mile south), Addington (1 mile north-west), Farleigh (1 mile south-west) and Selsdon (2 miles west). Larger places within reach include London (11 miles north), City of Westminster (13 miles north-west), Marylebone (13 miles north-west), Kensington (14 miles north-west), St Pancras (13 miles north) and Shoreditch (13 miles north).
Local landmarks in New Addington
Around New Addington, our work takes us to homes and buildings near Meridian High School and Addington Vale, among other places. The closest station to New Addington is Hayes (Kent) station, about 2.6 miles north-east. A little further out are Warlingham Park Hospital (1.8 miles south) and Bethlem Museum of the Mind (3.3 miles north-east). Open spaces near New Addington include Nore Hill and Hutchinson's Bank.