Greater London · England
Hackney External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Hackney and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Movement joints filled with mortar instead of sealant
- Movement joints with cracked, split or missing sealant
- Panel joints letting water in
What external mastic looks like in Hackney
Historic houses like Sutton House (about 0.3 miles north-west) are a reminder that the area around Hackney 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. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Managing a site like Berger Primary School? Then larger buildings have long runs of movement joint that eventually need resealing. Hackney is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Hackney is about 4 miles north-east of London, in Greater London. Hackney gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our Greater London coverage runs to 764 places, Hackney among them.
Every address in E9, E8, E3 and E5 is within our area for external mastic. That includes homes and businesses on Homerton High Street, Primrose Square and St John's Church Road. Being close to the A107 and B113, Hackney is easy for our applicators to reach. Close by, we work in Homerton (1 mile north), Lower Clapton (1 mile north), Hackney Central (1 mile west), London Fields (1 mile south-west) and Cambridge Heath (1 mile south-west). Within a short drive, we also cover London (4 miles south-west), City of Westminster (5 miles south-west), Marylebone (5 miles south-west), Kensington (7 miles south-west), St Pancras (3 miles west) and Walthamstow (3 miles north).
What’s near Hackney
Locally, jobs take us to homes and businesses close to The Urswick School, Clapton Park and Chesham Arms. There’s a railway station in Hackney itself: Homerton station. Other landmarks nearby include Hackney Walk (within half a mile north-west) and Cell Project Space (0.9 miles south-west). Open spaces near Hackney include Tower Hill and Old Ford Island.
External mastic in Hackney
External mastic is a job where short cuts show quickly. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We strip the joint back and start again. We work on brickwork movement joints, render & cladding joints and concrete & block, and people most often call us about movement joints filled with mortar instead of sealant and failed seals between different materials.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
There’s a 12-month guarantee on every job, large or small.
- Place
- Hackney (E9, E8, E3, E5)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Why deal with it now?
Sealing over the top of old mastic doesn’t hold for long. The new layer cannot bond properly to old, weathered material, so we always take the old sealant out. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Hackney, the repair is bigger than a sealant job.
We don’t show prices on the website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or email us.
Why choose Mr Mastic in Hackney
- Quality sealants from Arbo and Everbuild
- Old sealant always removed completely
- A 12-month guarantee on all work
- White, clear, grey or coloured to suit, where the product allows
Take a look at how sealant jobs are priced and our reviews.
Also near Hackney
Also in Hackney
When something else is needed
Sealant isn’t the answer to every problem, and we’ll tell you before we start. Sealant won’t put right:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Loose or hollow render, which needs re-rendering
- Cracks in the bricks or render themselves, away from the joints
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
Surfaces we seal
- Render & cladding joints
- Joints between brick and frames
- Copings & trims
- Façade panels
- Brickwork movement joints
- Concrete & block
Can I do it myself?
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
Surface by surface
Brickwork movement joints
People sometimes point up a brick movement joint by mistake. If that’s happened, we rake it out and reseal it properly if the joint can be cleared.
Render joints
The face of render can be soft, so a low-modulus sealant is kinder to the joint edges. We prime where the product needs it.
Hackney: your questions answered
Do you cover Hackney for external mastic?
Yes. Our work covers London and the South East, and Hackney is part of that. Just ring 0345 464 0079 or email us with a few details of the job.
Is parking a problem for a job in Hackney?
Parking in Hackney, 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.
Where is Mr Mastic based?
Mr Mastic is based in Crawley. Our applicators cover Hackney, along with the rest of our area.
Do you work for letting agents?
Yes. We work for householders, landlords, letting agents, businesses and hotels across Greater London.
What should I tell you?
The location, the problem and the rough size of the job. If you can, email a few photos.
Are you fully insured?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Should I try DIY first?
It depends on the job. High-level, external movement and fire-rated joints are professional jobs.
Can you seal joints between render and window frames?
Yes. Joints between dissimilar materials are a big part of external work. We use a flexible sealant suited to both surfaces, primed where needed.
For landlords and businesses
In hotels, rooms out of use cost money, so we plan the work room by room. We have worked in hotels as well as homes and businesses.
Housing providers, facilities teams and property managers book us too in Hackney and across Greater London. We can quote a run of properties together, and we are fully insured for the work.
How it works
On the day, we start by going over the job with you, so you know exactly what we are doing. Surfaces next to the work are protected before any work begins. Most jobs take a few hours for a handful of joints, longer for a whole elevation. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Hackney. A visitor permit or a nearby bay makes the visit run more smoothly.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
How to prepare
- Mention any tricky access
- Let us know about earlier repairs to the joints
- Tell us about any water getting in
How to get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we will explain what’s involved before giving you a price.
Advice
Common problems we fix in Hackney
Weeds, moss and debris in a joint are a sign the sealant has gone. Roots and dirt hold water against the wall and speed up the damage.
These are the problems we’re asked about most:
- Joints pointed up with cement by mistake
- Brick movement joints where the sealant has split
- Old sealant gone brittle and cracked
- Rain getting behind render or cladding at a joint
In the older streets around Church of St Luke, an extension built onto an older house moves differently, and the joint between them takes the strain.
Questions to ask before booking
- Are they insured?
- Who does the work, and how experienced they are
- What product goes in the joint
- Whether you can choose the colour