Greater London · England
Agar Town External Mastic
External mastic for Agar Town, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Joints pointed up with cement by mistake
- Joints where the bead has come unstuck
- Joints with sealant missing in places
How we handle external mastic in Agar Town
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 take the old material out and do it properly. We work on render & cladding joints, brickwork movement joints and concrete & block, and people most often call us about water getting into walls through failed joints and gaps where render, brick and frames meet.
Outside work in London starts with access: side passages, upper floors and where to park. In Agar Town, joints up high may need ladders or other access, which is worth talking through when you book.
Each job carries a 12-month guarantee, large or small.
- Where
- Agar Town (NW1W, NW1, N1)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Agar Town questions
Can you help a landlord with a rental near Camden Road station?
Yes. We work for landlords and agents as well as householders, and several properties can be quoted together. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Can you do external mastic in Agar Town?
Yes, Agar Town is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or email us and let us know what needs doing, and we’ll give you a clear price.
How long does external mastic take?
That depends on the amount of work, but most jobs take anything from a few hours to several days, depending on the building. We will tell you when we quote.
How long does external mastic last?
That varies with the weather the wall faces, how much it moves and the sealant used. Sealant is a maintenance item, so check the joints once a year and renew it when it starts to fail.
Can you seal joints between two different materials?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. The colour is chosen to suit.
When is the sealant fully cured?
It depends on the product and the temperature. We tell you how long to leave it before we go.
Is the work guaranteed?
Yes: twelve months. If anything is not right with the work within the year, let us know and we’ll sort it.
Can you work on commercial sites?
Yes. We work in offices, washrooms, hotels and other commercial premises. We can talk about working times when we quote.
Towns and villages near Agar Town
Other services in Agar Town
How it works
A visit follows a simple pattern: we check the joints, protect the area around them, carry out the job and tidy away. It normally takes a few hours to a few days, depending on the length of joint and the access. In Agar Town, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Getting ready for the visit
- Keep children and pets away from the work area
- For indoor joints, keep the area dry beforehand if you can
- Tell us about any water getting in
Ask for a quote
We don’t publish a price list, as no two jobs are quite the same. Instead, we give you a clear price for your job. To arrange one, ring 0345 464 0079 or drop us an email.
Advice
What the job involves on each surface
Render joints
Render is weaker at the surface than brick, so a sealant that stretches easily protects the edges. Priming is done where the sealant calls for it.
Cladding and façade panels
Where a cladding system has its own specified sealant, we follow it. Send us any details you have about the façade.
Keeping the joints in good condition
Good habits help new joints last longer. A few tips:
- Show decorators and builders where the movement joints are
- Avoid pressure-washing directly into sealant joints
- Get split or bare joints resealed while the damage is small
- Keep soil, plants and ivy away from the joints
Look over the joints once a year, ideally after winter. Watch for splits, edges coming away or growth in the joint.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
When it isn’t the sealant
It helps to know what we can’t do too:
- Cracked brickwork or render that needs a builder or plasterer
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Structural movement, which needs a surveyor or engineer
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we’ll tell you honestly before booking.
What we seal
- Joints between brick and frames
- Façade panels
- Brickwork movement joints
- Copings & trims
- Concrete & block
- Render & cladding joints
Can I do it myself?
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it does not work out, we can still put it right.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Outside joints around Agar Town
With historic houses such as Winfield House (about 1.5 miles west) nearby, there’s older building stock in the area around Agar Town as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For site and facilities teams at buildings such as Abacus Belsize Primary School, its movement joints, gutters and trims need looking after like any other building’s. If you let a flat or house near Camden Road station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Agar Town is about 1 mile north-west of St Pancras, in Greater London. From the centre of Agar Town to the outskirts, external mastic is available for homes and businesses alike. Agar Town is one of 764 places in Greater London we cover for external mastic.
Here we cover the NW1W, NW1 and N1 postcode area for external mastic. That includes homes and businesses on Water Lane, Maiden Lane and Camden Road. With the A400 and A5200 close by, Agar Town is easy for our applicators to reach for external mastic. We also cover Camden Town (1 mile west), Somers Town (1 mile south), Kings Cross (1 mile south-east), Kentish Town (1 mile north-west) and Barnsbury (1 mile north-east). Larger places within reach include London (3 miles south-east), Kensington (4 miles south-west), Walthamstow (6 miles north-east), Whitechapel (3 miles south-east), Ruislip (12 miles west) and Brompton (3 miles south-west).
What’s near Agar Town
Typical jobs here are in homes near Vaughan Williams Memorial Library, Golden Lion pub and North Bridge House School. You will also find Regent High School (within half a mile south) and Lewis Cubitt Park (less than half a mile east). There’s a railway station in Agar Town itself: Camden Road station. Other landmarks nearby include St Pancras Hospital (within half a mile south) and Montfichet's Tower (2.2 miles south-east). The countryside around Agar Town includes Barnsbury Wood and St. James's Park Lake.
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together, and we’re fully insured.
We regularly work with letting and managing agents. Tell us the address, the job and how access works.
When to call us in Agar Town
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it cannot stretch and rips as the joint opens.
These are the problems we’re asked about most:
- Failed seals between different materials
- Movement joints filled with mortar instead of sealant
- Weeds or debris growing in open joints
- Old sealant gone brittle and cracked
As a London address, Agar Town can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Before booking anyone
- What guarantee comes with the work
- Are they insured?
- How the colour is chosen
- How the joint is cleaned and prepared