Greater London · England
External & façade joints in Mottingham, Greater London
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Mottingham and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Brick movement joints where the sealant has split
- Leaking joints around cladding and façade panels
- Rigid filler in a joint that should flex
External mastic for homes and businesses in Mottingham
Joints between dissimilar materials, like brick against render or concrete against a steel frame, see movement from both sides. A flexible sealant bridges the two. If you’re dealing with weathered mastic that no longer stretches and joints where the bead has come unstuck, we can help.
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. For a flat in Mottingham, check the lease for who looks after the outside.
Whatever the size of the job, you get the same 12-month guarantee in Mottingham and across Greater London.
- Where
- Mottingham (SE9, SE12, BR1)
- Wider area
- Greater London
- Cover
- A year, on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
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 the old joint is cut out fully first. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
Leaving a failed joint generally makes the job bigger, not smaller. If you are not sure whether it needs doing, call 0345 464 0079 or drop us an email and we will give you an honest view and a quote.
Why Mottingham customers choose us
- Sanitary silicone with an anti-fungal additive in wet areas
- Homes, businesses and hotels
- A 12-month guarantee on all work
- Any old sealant cut out fully, not covered over
What affects the cost of external mastic
We do not publish a price list. The quote depends on:
- Mould in or behind the old joints
- Whether old sealant or filler has to be cut out
- The amount of work
- Working hours on commercial sites
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
What we need to know
Photos by email are helpful but not essential. Try to tell us:
- The rough size of the job
- Where the job is, and your postcode
- The type of property
- What’s wrong with the joints now
To get a quote, ring 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. We’ll give you a clear quote before any work starts.
Walls and rooflines in Mottingham
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. Historic houses like Eltham Palace (about 1.1 miles north-east) are a reminder that the area around Mottingham has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
For site and facilities teams at buildings such as Marvels Lane Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Mottingham is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Mottingham is about 1 mile south-west of Eltham, in Greater London. Every kind of property in Mottingham can book us for external mastic. Every job comes with our 12-month guarantee. Our Greater London coverage runs to 764 places, and Mottingham is one of them. You can also see our page for London, about 7 miles away.
Every address in SE9, SE12 and BR1 is within our area for external mastic. Local streets include Horley Road, Dorset Road and Albert Road, and we cover them all. Neighbouring places we cover for external mastic include Chinbrook (1 mile south-west), Grove Park (1 mile west), Coldharbour (1 mile east), Middle Park (1 mile north) and Horn Park (1 mile north-west). Further out, we also cover London (7 miles north-west), City of Westminster (10 miles north-west), Marylebone (10 miles north-west), Kensington (11 miles north-west), St Pancras (9 miles north-west) and Shoreditch (8 miles north-west).
Around Mottingham
Locally, jobs take us to homes and businesses close to Colfe's School, Chinbrook Meadows and Haberdashers' Aske's Knights Academy. Mottingham’s nearest station is Grove Park station, about 0.7 miles west. A little further out are Greenwich Castle (3.5 miles north-west) and Prefab Museum (1.7 miles west). The countryside around Mottingham includes Summer Hill and The Tarn.
Common questions in Mottingham
Do you work for landlords with property near Grove Park station?
Yes. We work for letting agents and landlords as well as householders. You can ring 0345 464 0079 or drop us an email with the details for a clear quote.
Is parking a problem for a job in Mottingham?
Parking in Mottingham, 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.
How long does the job take?
Most jobs take a few hours for a handful of joints, longer for a whole elevation, including the preparation. We will confirm how long when we quote.
Will the new joint stand out?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We choose the closest to your brick or render.
When will the joints need doing again?
It varies with how exposed the wall is and how much the joint moves. Look for splits, hardening or edges coming away, and reseal at that point.
What’s an expansion joint in brickwork?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It should be filled with flexible sealant, never mortar.
What do you need from me for a quote?
Only a few details: where it is, what you’ve noticed and how we reach it. Then phone 0345 464 0079 or send us an email.
Which products do you use?
Products from Arbo and Everbuild, among others, chosen to suit the joint. We will tell you what we’re using and why.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Towns and villages near Mottingham
Also in Mottingham
Keeping the joints in good condition
After the cure time, these simple habits help:
- Tell anyone working on the walls about the movement joints
- Never let anyone fill a movement joint with mortar
- Keep water from gutters off the wall
- Clear growth from the base of walls and joints
Do not paint over the new sealant unless we have said the product is paintable. Paint can crack on a flexible joint.
Act while the splits are small. Then it’s a straightforward cut-out and reseal before water has had years to get in.
Common problems we fix in Mottingham
Using the wrong sealant is another common reason. A high-modulus or general-purpose sealant can be too rigid for a busy joint, so it pulls away from the edges.
The most common problems we see are:
- Joints with sealant missing in places
- Joints where the bead has come unstuck
- Hard, crazed mastic that has stopped moving
- Joints pointed up with cement by mistake
For an older house near a landmark such as Jubilee International Church, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Comparing quotes
- What happens if the job turns out different
- What the cure time is
- How the surfaces are prepared before sealing
- Who does the work, and how experienced they are
Landlord and commercial work in Mottingham
Failed sealant is one of the commonest items on a check-out report. Several properties can go on one quote.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a 12-month guarantee.
What we do, step by step
All our tools and materials come with us in the van, so you don’t need to buy or prepare anything. Once we have agreed what’s being done, the area is protected and the work begins. Most jobs take a few hours to a few days, depending on the length of joint and the access. In a London area like Mottingham, 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 look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Tell us if parking is tricky
- Keep pets and children clear of the area while we work
- Tell us about any previous sealing or DIY attempts
Getting a quote
Need a quote? Please call 0345 464 0079 or drop us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.