Greater London · England
External Mastic in Clare Market
External mastic in Clare Market from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Failed sealant between panels on a façade
- Movement joints filled with mortar instead of sealant
- Sealant pulling away from one side of the joint
Common problems we fix in Clare Market
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. The joint cannot move, so the wall cracks somewhere else instead.
The most common problems we see are:
- Weeds or debris growing in open joints
- Gaps where render, brick and frames meet
- Panel joints letting water in
- Old sealant gone brittle and cracked
Managing a site like St Clement Danes CofE Primary School? Then larger buildings have long runs of movement joint that eventually need resealing.
What your quote should include
- The length of the guarantee
- Who does the work, and how experienced they are
- How long to leave it before use
- What the quote includes, VAT included or not
External mastic for homes and businesses in Clare Market
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we will confirm what access is needed. If you are dealing with plants rooting in failed movement joints and joints with sealant missing in places, we can put it right, whatever the surface.
Outside work in London starts with access: side passages, upper floors and where to park. For a home in Clare Market, tell us how high the joints are and how to reach the back of the building.
A 12-month guarantee comes as standard, so you are covered after we’ve gone.
- Place
- Clare Market (WC2H, W1D, WC2B)
- Region
- Greater London
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What the job involves on each surface
Concrete and blockwork
Concrete faces can be dusty and porous, so cleaning and priming matter. A primer goes on where the product requires one.
Copings and trims
A failed coping joint lets water into the top of the wall. Sealing them early saves the wall below.
Clare Market: your questions answered
Can parking be tricky for a visit in Clare Market?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
I let a flat near London Charing Cross station. Can you help?
Yes, landlords and agents are among the people we work for. Just phone 0345 464 0079 or email us with the address and what needs doing, and we will give you a clear price.
What colours does the sealant come in?
We choose a sealant colour to suit the brick, stone or render, so the joint sits quietly in the wall. There’s a wide choice of exterior colours.
Where do you work from?
We’re a Crawley-based firm. Our area covers South East England, London and Scotland.
Will it make a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
What sealant do you use?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we’ll tell you what we are using.
Do you seal joints where cladding meets other materials?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. We pick a colour that works with both materials.
Can you seal over the old sealant?
No, and we never do. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
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.
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
The process
We bring everything the job needs with us. Once we have agreed what’s being done, the area is protected and the work begins. It normally takes a few hours for a handful of joints, longer for a whole elevation. In a London area like Clare Market, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- We start by walking round the building and agreeing the joints and the access.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Move anything stored near the joints
- Mention any tricky access
- Keep pets and children clear of the area while we work
Ask for a quote
If you’re in Clare Market and need external mastic, call 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
Read more
Also near Clare Market
Other services in Clare Market
What happens if it’s left?
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 a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote.
Why book with us
- We leave the area clean and tidy
- 20+ years of sealant experience
- Approved under the ARBOMaster scheme
- Sealant colour chosen to suit
Read our cost guide or customer reviews.
Walls and rooflines in Clare Market
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. Historic houses like Dr Johnson's House (about 0.4 miles east) are a reminder that the area around Clare Market has older buildings as well as new. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth.
Clare Market is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. For landlords with property near London Charing Cross station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Clare Market is about 1 mile south of St Pancras, in Greater London. Homes, rented property, offices and hotels in Clare Market can book us for external mastic, old or new, large or small. The work is guaranteed for a year. We cover 764 towns and villages across Greater London, from the larger towns to small villages.
Here we cover the WC2H, W1D and WC2B postcode area for external mastic. If you need external mastic at a property on Drury Lane, New Square and Old Square or anywhere close by, we can help. Being close to the A4 and A301, Clare Market is simple for us to get to. Neighbouring places we cover for external mastic include Aldwych (1 mile south), Temple Bar (1 mile east), Covent Garden (1 mile south-west), Temple (1 mile south-east) and Seven Dials (1 mile west). Larger places within reach include Kensington (4 miles west), Walthamstow (6 miles north-east), Hampstead (4 miles north-west), Ruislip (13 miles west), Stockwell (3 miles south) and Orpington (13 miles south-east).
Landmarks near Clare Market
In Clare Market, that means homes and buildings near Lincoln's Inn Fields, London Nautical School and LSE Shaw Library. You’ll also find Ye Old White Horse pub (within half a mile north) and Mercers' School (under half a mile north-east). Clare Market’s nearest station is London Charing Cross station, about 0.6 miles south-west. A little further out are St Philip's Hospital (less than half a mile north-west) and Montfichet's Tower (0.7 miles east). Open spaces near Clare Market include Ludgate Hill and St. James's Park Lake.
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together.
Mouldy or split sealant often shows up at the end of a tenancy. We can quote for more than one property at once.
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Keep high-pressure jets off the joints
- Make sure movement joints are not pointed over
- Check external joints each spring
- 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.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years so early resealing is worth it.