Greater London · England
External & façade joints in Nash, Greater London
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Nash and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Gaps where render, brick and frames meet
- Sealant that has lost its bond to the brick or render
- Leaking joints around cladding and façade panels
How we handle external mastic in Nash
Where two different materials meet, such as brick and render or blockwork and metal, they move at different rates. A flexible sealant bridges the two where a rigid filler would soon crack. If you’re dealing with movement joints filled with mortar instead of sealant and water getting into walls through failed joints, we can put it right, on brickwork movement joints, concrete & block and façade panels alike.
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 Nash, it’s worth checking who is responsible for the outside before booking.
A 12-month guarantee comes as standard, so you’re not left on your own once the job is done.
- Location
- Nash (BR2)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Price
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Honest limits
Honest advice matters more to us than a booking, so here’s what new sealant won’t do:
- Subsidence or other structural problems
- Adding movement joints to masonry that has none
- Cracking across the wall rather than at a joint
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly before booking.
What we seal
- Joints between brick and frames
- Copings & trims
- Façade panels
- Concrete & block
- Brickwork movement joints
- Render & cladding joints
How the visit works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours for a handful of joints, longer for a whole elevation and we leave things clean and tidy. In Nash, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Where the joints are inside, avoid wetting them before we arrive
- Move anything stored near the joints
- Mention any sign-in or site rules at work premises
Getting a quote
We don’t publish a price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, phone 0345 464 0079 or email us.
Advice
Leave it or put it right?
Running new sealant over the old bead rarely lasts. New sealant does not bond well to old, weathered sealant, so we always take the old sealant out. In a flat in Nash, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Instead of a standard rate, we look at what your job involves: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
Why choose Mr Mastic in Nash
- Domestic, commercial and hotel work
- Every job guaranteed for a year
- 20+ years of sealant experience
- We are fully insured
Take a look at how sealant jobs are priced and our reviews.
External mastic in Nash: local notes
With historic houses such as Down House (about 2.4 miles south-east) nearby, there’s older building stock in the area around Nash 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. 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 Keston Parish Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Managing a site like Wickham Common Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
Nash is about 3 miles south of Bromley, in Greater London. Our applicators cover external mastic for homes and businesses in Nash and the surrounding area. Across Greater London, we cover 764 places, and Nash is one of them. We also work in London, about 11 miles from Nash.
We cover every part of the BR2 postcode area for external mastic and the streets around it. Local streets include Nash Lane and North Pole Lane, and we cover them all. We also cover Keston (1 mile east), Leaves Green (1 mile south-east), Hayes (1 mile north), New Addington (2 miles south-west) and Farthing Street (2 miles south-east). Within a short drive, we also cover London (11 miles north-west), City of Westminster (13 miles north-west), Marylebone (13 miles north-west), Kensington (14 miles north-west), St Pancras (13 miles north-west) and Shoreditch (12 miles north).
Local landmarks in Nash
Typical jobs here are in homes near The Greyhound pub, All Saints Catholic School and Coney Hall Recreation Ground. The nearest railway station is Hayes (Kent) station, about 1.4 miles north of the centre. Nearby you’ll also find The Mall (3.2 miles north) and Bethlem Museum of the Mind (1.8 miles north). The countryside around Nash includes Hutchinson's Bank and Summer Hill.
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Fix overflowing gutters above sealed joints
- Don’t let climbing plants root in the sealant
- Never let anyone fill a movement joint with mortar
- Get split or bare joints resealed while the damage is small
Don’t paint over the new sealant unless we have said the product is paintable. Many exterior sealants aren’t designed to be painted, and paint can crack as the joint moves.
Leave a failed movement joint and water keeps getting into the wall. Over time it can mean damp inside, stained render or frost-damaged brick, all bigger jobs than a reseal.
Nearby places to Nash
Also in Nash
What we’re called out for in Nash
Sometimes a movement joint was filled with mortar or a rigid filler by mistake. The joint can’t move, so the wall cracks somewhere else instead.
Look out for these signs:
- Moss and dirt in joints with no sealant left
- Panel joints letting water in
- Brick movement joints where the sealant has split
- Rigid filler in a joint that should flex
Rented homes near Hayes (Kent) station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
What your quote should include
- How the colour is chosen
- Whether VAT is included
- What product goes in the joint
- Who turns up on the day
DIY versus a professional finish
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it does not work out, we can still put it right.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Landlord and commercial work in Nash
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements.
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance.
FAQs for Nash
Do you cover Nash for external mastic?
Yes. We work across London and the South East, and Nash is part of that. Just phone 0345 464 0079 or email us with a few details of the job.
Is parking a problem for a job in Nash?
Parking in Nash, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Are you fully insured?
Yes. Mr Mastic is fully insured, and we have been doing sealant work for more than 20 years.
How long does external mastic take?
As a guide, most jobs take a few hours for a handful of joints, longer for a whole elevation. Bigger jobs take longer, and we will tell you how long to expect.
When is the sealant fully cured?
Many sealants skin over quickly but take longer to cure fully. We’ll tell you how long to leave the joint before we leave.
What is backing rod for?
The foam is closed-cell backing rod. It keeps the sealant at the right depth and bonded to the sides only.
What is a movement joint?
Most straight vertical gaps in brickwork are movement joints. It lets the bricks expand without cracking.
What colours does the sealant come in?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We pick the one that suits your wall best so it does not stand out.