Greater London · England
Lisson Grove External Mastic
Professional external mastic in and around Lisson Grove, with every bit of old sealant taken out first.
- Cracked joints where brick meets render or frames
- Sealant that has lost its bond to the brick or render
- Rain getting behind render or cladding at a joint
External mastic in Lisson Grove, done properly
Short cuts in external joints show up within a season or two. 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 are often asked to deal with weeds or debris growing in open joints and sealant that has lost its bond to the brick or render, across joints between brick and frames, concrete & block and copings & trims.
Modern London flats rely on sealed movement joints and cladding joints. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall, and both kinds of building are found across London.
You are covered for a year from the day we finish. If anything is not right with it, call 0345 464 0079 or email us.
- Location
- Lisson Grove (NW8, W1H, W2)
- Region
- Greater London
- Cover
- One year on every job
- Price
- A clear price before work begins
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Outside joints around Lisson Grove
With historic houses such as Winfield House (about 0.4 miles north-east) nearby, there’s older building stock in the area around Lisson Grove as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. 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 Gateway Academy, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Lisson Grove is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Lisson Grove is about 1 mile north-west of City of Westminster, in Greater London. Every kind of property in Lisson Grove is covered for external mastic. Every job comes with our 12-month guarantee. Lisson Grove is one of 764 towns and villages in Greater London where we work.
Every address in NW8, W1H and W2 is within our area for external mastic, from the main roads to the quietest streets. External mastic is available to properties on Hall Road, Park Road and Lodge Road. Lisson Grove sits on or near the A5 and A40, which makes travel easy. Neighbouring places we cover for external mastic include Paddington Green (1 mile south-west), Paddington (1 mile south), Little Venice (1 mile south-west), Connaught Village (1 mile south) and St John's Wood (1 mile north). Within a short drive, we also cover London (4 miles south-east), Shoreditch (4 miles east), Walthamstow (8 miles north-east), Hoxton (4 miles east), Whitechapel (4 miles east) and Ruislip (11 miles west).
Near you in Lisson Grove
Typical jobs here are in homes near RIBA Library, St John's Wood Art School and Regent's Park. Lisson Grove has its own railway station: London Marylebone station. Other landmarks nearby include Montfichet's Tower (3 miles east) and Maida Vale Hospital for Nervous Diseases (0.5 miles west). Green spaces nearby include The Long Water and Greville Place nature reserve.
Surface by surface
Brickwork movement joints
People sometimes point up a brick movement joint by mistake. Where one has been mortared, we cut it out and reseal it with sealant if the joint can be cleared.
Render joints
Render is weaker at the surface than brick, so a low-modulus sealant is kinder to the joint edges. Priming is done where the sealant calls for it.
Keeping the joints in good condition
A little care helps the new joints last. Our advice:
- Never let anyone fill a movement joint with mortar
- Get split or bare joints resealed while the damage is small
- Keep soil, plants and ivy away from the joints
- Avoid pressure-washing directly into sealant joints
Keep the joints clear of soil, plants and climbing growth. Anything that holds water against the joint wears it out sooner.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years so early resealing is worth it.
How we quote for external mastic
You will get a clear quote before we start. It’s based on:
- Whether there’s mould to deal with
- The size of the job
- When we can work, for business premises
- How easy the joints are to reach
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote.
What we need to know
When you call or email, these details help:
- Any previous sealing or DIY work
- What’s wrong with the joints now
- Where the job is, and your postcode
- A few pictures by email, if you can
There’s no standard price list, because every job is different. Instead, we give you a clear price for your job. To get started, phone 0345 464 0079 or email us.
Nearby places to Lisson Grove
Other services in Lisson Grove
What we do, step by step
There isn’t much for you to do on the day. Show us the job and we’ll take it from there. The work itself takes anything from a few hours to several days, depending on the building from start to finish. In Lisson Grove, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- First we look over the joints with you, agree which to renew and talk through access.
- The old mastic and anything lodged in the joint is removed.
- We clean both faces of the joint and prime them where the product calls for it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Before we arrive
- On commercial sites, let us know about site rules
- Move anything stored near the joints
- Try not to wet indoor joints just before the visit
Getting a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we’ll talk you through the work.
Advice
What we can’t put right
New sealant cannot fix everything, and we’ll tell you before any work starts. Sealant won’t put right:
- Failed render or damaged cladding panels
- Cracking across the wall rather than at a joint
- Cutting new joints into brickwork, which is building work rather than sealant work
If in doubt, ring 0345 464 0079 or send us an email and we will say what we think before booking.
Where we work in Lisson Grove
- Concrete & block
- Brickwork movement joints
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Copings & trims
Lisson Grove questions
Is parking a problem for a job in Lisson Grove?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly.
Is Lisson Grove in your area for external mastic?
Yes. Our work covers London and the South East, and Lisson Grove is part of that. Just ring 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear quote.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we are part of it.
Do you remove the old sealant?
Always. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Can you match the colour of my brickwork?
We choose a sealant colour to suit the brick, stone or render, so the joint sits quietly in the wall. Exterior sealants come in a good range of colours.
Is there a guarantee?
Yes, always. There’s a 12-month guarantee on every job, large or small.
Can you work on commercial sites?
Yes. We’ve worked for hotels, offices and other businesses.
Should I try DIY first?
It depends on the job. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
Do you need external mastic in Lisson Grove?
Sometimes a movement joint was filled with mortar or a rigid filler by mistake. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Any of these means the joints need attention:
- Moss and dirt in joints with no sealant left
- Joints where the bead has come unstuck
- Weathered mastic that no longer stretches
- Cracked joints where brick meets render or frames
If you live in an older home near St Paul's Community Church, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Before booking anyone
- What preparation is included
- Whether they’re fully insured
- What guarantee comes with the work
- How hidden problems are handled
For landlords and businesses
For anyone letting property in or around Lisson Grove, several properties can go on one quote. Send us the addresses and the work at each.
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.