Greater London · England
External & façade joints in Herne Hill, Greater London
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Herne Hill. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Rain getting behind render or cladding at a joint
- Hard, crazed mastic that has stopped moving
- Sealant that has lost its bond to the brick or render
External mastic in Herne Hill, done properly
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render so the line blends in. We work on façade panels, copings & trims and render & cladding joints, and common reasons people get in touch are brick movement joints where the sealant has split and movement joints filled with mortar instead of sealant.
In London terraces and converted houses, gutters and walls are often shared with the house next door, so one failed joint can cause damp for more than one household. In a converted house in Herne Hill, it’s worth checking who is responsible for the outside before booking.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Location
- Herne Hill (SE22, SW2, SE24)
- Region
- Greater London
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
How we quote for external mastic
The quote reflects the job in front of us. We take into account:
- Working hours on commercial sites
- Any mould that needs treating
- How much old sealant there is and how hard it is to remove
- The type of sealant required
What it costs depends on the size of the job, how much old material has to come out and access to the work. We give a clear quote before work begins, so you know where you stand.
What we need to know
When you call or email, it’s useful to know:
- A few photos by email, if you can
- What the problem is, such as mould, gaps, leaks or cracking
- Roughly how big the job is
- How we’d reach the joints
If you’re in Herne Hill and need external mastic, phone 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and you’ll get a clear quote before any work starts.
How the visit works
Our applicators work methodically: protect, prepare, seal, tidy. Typically it takes anything from a few hours to several days, depending on the building and we leave things clean and tidy. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Herne Hill. It helps if you can point us to a visitor permit or a bay close to the door.
- Each joint is checked and the colour of the new sealant agreed.
- 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.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Preparing for the visit
- Tell us about any water getting in
- Let us know about stairs, lifts or work at height
- Move anything stored near the joints
Get a quote
Getting a quote is simple: let us know the job and the location. A few photos by email make the job easier to understand, and we’ll take it from there.
Advice
Landlord and commercial work in Herne Hill
Letting agents and landlords in Herne Hill can book us as well as householders. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
Your questions about external mastic in Herne Hill
Can you do external mastic in Herne Hill?
Yes. We work across London and the South East, and Herne Hill is part of that. You can ring 0345 464 0079 or drop us an email and tell us what needs doing, and we will give you a clear price.
Do you work for landlords with property near North Dulwich station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
Where do you work from?
We work from Crawley. We cover Herne Hill and the rest of Greater London, along with the rest of our area.
Do the sealants smell?
Some sealants have a smell while they cure, which fades as it sets. Opening a window helps.
Do you seal joints where cladding meets other materials?
Yes. Joints between dissimilar materials are a big part of external work. The sealant is chosen to bond to both sides with primer where required.
Which products do you use?
We choose the sealant for the joint, not the other way round. Where it moves, gets wet or faces the weather makes a difference, and we’ll tell you what we’re using.
Do you use backing rod?
Backing rod goes into deeper joints as a matter of course. It sets the sealant depth and prevents three-sided bonding.
How often do external joints need resealing?
It varies from wall to wall: sunny, exposed elevations and busy joints wear faster. A yearly look will tell you when they need doing. Every job carries our 12-month guarantee.
Surface by surface
Copings and trims
Metal and stone copings both move with temperature, so the joints need a sealant that stays flexible year round.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
DIY sealant or a professional job?
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly, so just mention it when you contact us.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions.
Also near Herne Hill
More services for Herne Hill
Why deal with it now?
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.
Combining jobs into one visit normally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. We’ll send you a clear quote for the lot.
Why book with us
- Sealant colour chosen to suit
- Over 20 years’ experience
- We agree the colour with you first
- A choice of colours where the product allows
See what affects the cost and customer reviews.
What we can’t put right
Before you book, it’s worth knowing the limits too:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Subsidence or other structural problems
- Cracked brickwork or render that needs a builder or plasterer
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think before you book.
Surfaces we seal
- Brickwork movement joints
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Concrete & block
- Copings & trims
Herne Hill buildings and the weather
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Rented homes near North Dulwich station change hands often, and split movement joints are easy to miss on a rental until damp shows inside. If you look after a building such as Judith Kerr Primary School, its movement joints, gutters and trims need looking after like any other building’s. Herne Hill is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Herne Hill is about 3 miles south of London, in Greater London. Herne Hill gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Herne Hill is one of 764 places in Greater London we cover.
Here we cover the SE22, SW2 and SE24 postcode area for external mastic. You will find streets such as Jelf Road, Dewey Lane and Talma Road, all of which we cover. Herne Hill sits on or near the A204 and A2214. We also cover Dulwich Village (1 mile south-east), East Dulwich (1 mile north-east), Dulwich (1 mile south-east), Denmark Hill (1 mile north) and Camberwell (1 mile north). Within a short drive, we also cover London (3 miles north), City of Westminster (5 miles north-west), Marylebone (5 miles north-west), Kensington (6 miles north-west), St Pancras (5 miles north) and Shoreditch (5 miles north).
Near you in Herne Hill
Locally, jobs take us to homes and businesses close to The Charter School, Half Moon pub and Belair Park. Herne Hill has its own railway station: North Dulwich station. Other landmarks nearby include Surrey Quays Shopping Centre (3.5 miles north-east) and House of Dreams Museum (0.7 miles north-east). For a walk, there’s Battersea Park Lake and Knight's Hill.