South East England and London
External Mastic in City of London
From the largest town to the smallest village in City of London, our applicators can help with external mastic. A clear quote before we start, and a one-year guarantee.
Where we work in City of London
Sealing brickwork movement joints, render, cladding and façade joints. Choose your town from the list to see local details, and call or email us for a quick quote.
Main towns
Other services in City of London
- Sand mastic for sash & case windows
- New-build mastic & snagging
- Regrouting
- Fire-rated sealant
- Glazing & conservatory sealant
- Bathroom & kitchen resealing
- Commercial & hotel sealant
- Window & door mastic
- Floor & skirting joints
- Gutter, fascia & soffit sealing
- Remedial sealant & repairs
Postcode districts
How external mastic works in City of London
Getting the depth right is half the job. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, leaving it bonded to two faces so it can move with the wall. We work on copings & trims, brickwork movement joints and joints between brick and frames, and the jobs we see most are hard, crazed mastic that has stopped moving and plants rooting in failed movement joints.
Good joint work is mostly preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes anything from a few hours to several days, depending on the building.
- First, the joints are inspected and the access agreed.
- 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.
Pricing in City of London
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 drop us an email.
Why clients in City of London choose us
- We never seal over old sealant
- Arbo and Everbuild products
- Sanitary silicone with an anti-fungal additive in wet areas
- 20+ years of sealant experience
How to get a quote
Want a quote for external mastic? Please phone 0345 464 0079 or email us and tell us about the job. We’ll explain what we’d do and send you a clear quote before we start.
Near you in City of London
Around City of London, our work takes us to homes and buildings near Fashion Retail Academy, Prior Weston Primary School and Children's Centre and Barts Health Archives. You’ll also find Golden Fleece pub (less than half a mile south), St Alphage Garden (under half a mile north), Central Foundation Boys' School (0.8 miles north) and St Mary-at-Hill (0.5 miles south-east). There’s a railway station in City of London itself: London Cannon Street station. A little further out are Gabriel's Wharf (0.8 miles south-west) and London Mithraeum (under half a mile south). Green spaces nearby include St. James's Park Lake and Barnsbury Wood.
- Places of worship nearby include St Olave Old Jewry (within half a mile east)
Walls and rooflines across City of London
From City of London to its smaller places, buildings across City of London have walls, gutters and rooflines of every age. All of them move, so they need a flexible sealant at the right depth.
From Victorian terraces to post-war new towns and modern estates, homes across the South East and London cover every era. Each needs the right sealant for its age and materials.
City of London: For an older house near a landmark such as St Olave Old Jewry, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Rented homes near London Cannon Street station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets.
Quotes for external mastic in City of London
We do not publish a price list. What we look at:
- Whether there’s mould to deal with
- How much there is to do
- The product the joint needs
- When we can work, for business premises
Instead of a standard rate, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Asking for a quote
Photos by email are helpful but not essential. Try to tell us:
- The type of property
- How many joints, rooms or windows are involved
- Where the job is, and your postcode
- What the problem is, such as mould, gaps, leaks or cracking
If you are in City of London and need external mastic, call 0345 464 0079 or send 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.
Work for landlords, hotels and businesses
Letting agents often deal with us directly. Tell us the address, the job and how access works.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Common problems we fix in City of London
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.
These are the problems we are asked about most:
- Moss and dirt in joints with no sealant left
- Panel joints letting water in
- Rain getting behind render or cladding at a joint
- Rigid filler in a joint that should flex
What happens if it’s left?
Sealing over the top of old mastic does not hold for long. New sealant does not bond well to old, weathered sealant, so the old joint is cut out fully first.
What your quote should include
- How the colour is chosen
- How hidden problems are handled
- Are they insured?
- How the surfaces are prepared before sealing
When something else is needed
We will not take on work that will not last, so these are the limits:
- Loose or hollow render, which needs re-rendering
- Movement that is more than a sealant joint can take
- Rising or penetrating damp from elsewhere in the wall
City of London: your questions answered
Is the work guaranteed?
Yes. All our work carries our 12-month guarantee.
Where do you work from?
We’re a Crawley-based firm. We work across South East England, London and Scotland.
Are you insured?
Yes. We’re fully insured.
Can new sealant go over the old?
No, it won’t last. It can look neat for a few weeks, but the new bead soon lifts. The old sealant has to come out completely.
Can I do it myself?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. If it doesn’t work out, we can redo it.
Do you seal joints where cladding meets other materials?
Yes. We cut out the old sealant, prepare both faces and reseal with a flexible exterior product. We pick a colour that works with both materials.
What do you need from me for a quote?
A short description and the location, plus pictures if you have them. We will ask anything else we need to know.