Greater London · England
External Mastic in Anerley
External mastic for Anerley, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Rain getting behind render or cladding at a joint
- Failed seals between different materials
- Joints where the bead has come unstuck
About our external mastic in Anerley
Joints between dissimilar materials, like brick against render or concrete against a steel frame, see movement from both sides. A flexible exterior sealant takes up that movement where mortar or filler would crack. We work on concrete & block, brickwork movement joints and façade panels, and common reasons people get in touch are rain getting behind render or cladding at a joint and weeds or debris growing in open joints.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Anerley, tell us how high the joints are and how to reach the back of the building.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Anerley (SE20, SE19, SE26)
- Region
- Greater London
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
How the job changes by surface
Cladding and façade panels
If the façade has a specified sealant, that is what we use or an approved alternative. Send us any details you have about the façade.
Joints between dissimilar materials
Different materials may need different primers. Both surfaces are cleaned and primed as the product requires.
Other services in Anerley
How we quote for external mastic
There’s no set price list. The quote depends on:
- The size of the job
- When we can work, for business premises
- Mould in or behind the old joints
- How many rooms, windows or areas are involved
What you pay reflects the work, not a rough estimate. That’s why we ask a few questions first.
Helping us quote
When you call or email, it’s useful to know:
- Whether it’s a home or a business
- Where the job is, and your postcode
- Pictures of the joints, sent by email
- How many joints, rooms or windows are involved
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.
When to call us in Anerley
Joints sealed without backing rod, or far too deep, rarely last. Sealant bonded to three sides has nowhere to go and tears as soon as the joint widens.
Any of these means the joints need attention:
- Failed sealant between panels on a façade
- Gaps where render, brick and frames meet
- Movement joints filled with mortar instead of sealant
- Plants rooting in failed movement joints
If you let a flat or house near Anerley station, split movement joints are easy to miss on a rental until damp shows inside.
Before you book anyone
- How much experience the applicator has
- Whether VAT is included
- Which colour the sealant will be
- What the cure time is
What happens if it’s left?
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That protects surfaces like brick, render and concrete. Too stiff a sealant can pull at the edges and break them. 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.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we will explain what it covers.
Why us?
- One-year guarantee on every job
- Trusted Arbo and Everbuild sealants
- More than 20 years in sealant work
- Tidy, careful work
See our cost guide and our reviews.
For landlords and businesses
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we will give you a quote.
FAQs for Anerley
Is Anerley in your area for external mastic?
Yes, Anerley is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job.
Can you help a landlord with a rental near Anerley station?
Yes, landlords and agents are among the people we work for. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we will give you a clear quote.
Do the sealants smell?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
Can you seal joints between render and window frames?
Yes. Joints between dissimilar materials are a big part of external work. The sealant is chosen to bond to both sides, primed where needed.
What do you need from me for a quote?
Where the job is, what the problem is and roughly how big it is. Photos by email help too.
Can you do several jobs on one visit?
Of course. Combining jobs makes good use of the visit.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
Will it make a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
Outside joints around Anerley
With historic houses such as Kingswood House (about 1.3 miles north-west) nearby, there’s older building stock in the area around Anerley as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Schools such as James Dixon Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. As a London address, Anerley can be tricky for parking: let us know about parking bays, permits or a driveway.
Anerley is about 2 miles north-east of Thornton Heath, in Greater London. Jobs in Anerley get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Our Greater London coverage runs to 764 places, and Anerley is one of them. London is on our list too, around 6 miles away.
Every address in SE20, SE19 and SE26 is covered for external mastic. Whether your property is on Maple Road, Padua Road and Genoa Road or anywhere close by, we can help. Nearby, we also carry out external mastic in Penge (1 mile east), Crystal Palace (1 mile north), Sydenham (1 mile north-east), Gipsy Hill (1 mile north-west) and Upper Norwood (1 mile west). Further out, we also cover London (6 miles north), City of Westminster (8 miles north-west), Marylebone (8 miles north-west), Kensington (8 miles north-west), St Pancras (8 miles north) and Shoreditch (8 miles north).
Around Anerley
In Anerley, that means homes and buildings near Crystal Palace School, Crystal Palace Dinosaurs and Harris City Academy Crystal Palace and the streets around them. There’s a railway station in Anerley itself: Anerley station. Other landmarks nearby include Crystal Palace Museum (0.5 miles north-west) and Whitgift Centre (3.1 miles south-west). The countryside around Anerley includes Dulwich Upper Wood and Knight's Hill.
How it works
We work through the job in order: protect, prepare, seal, tidy. For most jobs that takes a few hours to a few days, depending on the length of joint and the access and we leave things clean and tidy. For a job in Anerley, parking and access are the things to plan: 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.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Tell us about any water getting in
- Keep pets and children clear of the area while we work
- Try not to wet indoor joints just before the visit
Getting a quote
For external mastic in Anerley, phone 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and you will get a clear quote before work begins.
Related advice
Looking after it afterwards
So the new joints stay in good condition:
- Clear growth from the base of walls and joints
- Keep water from gutters off the wall
- Never let anyone fill a movement joint with mortar
- Leave the joints unpainted unless we’ve said otherwise
Make sure anyone working on the wall later knows where the movement joints are. They must stay as flexible joints, never rendered or pointed over.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.