City of London · England
Mastic man in City of London
Sealant work for offices, hotels and the Square Mile’s residential estates, from the Barbican and Golden Lane to Middlesex Street.
- Old sealant cut out, never covered
- ARBOMaster approved
- One-year guarantee on every job
Sealant jobs we do in City of London
The City of London is mostly offices, but it also has homes, hotels and a hospital, and all of them depend on sound sealant joints. Mr Mastic covers the Square Mile from our base in Crawley, renewing silicone in washrooms, showers and kitchens, sealing around windows and doors, and carrying out commercial sealant work for building managers and facilities teams.
Working in the City is different from working in a suburb. Buildings are busy in the day and quiet at night, access is controlled, and parking is close to impossible. We plan each job around that: agreeing times with building management, bringing only what we need, and leaving the area clean so it goes straight back into use. The sealing itself stays the same: old material fully removed, surfaces cleaned and prepared, and the right Arbo or Everbuild product applied neatly.
Concrete estates and modern towers in the Square Mile
Only around 9,000 people live in the City, and most of them live in a few large estates. The Barbican Estate, built between 1965 and 1976 by Chamberlin, Powell and Bon, has about 2,000 flats, maisonettes and houses, including three 42-storey towers, and is Grade II listed. Its exposed concrete is part of the design, and residents follow listed building management guidelines that help decide which alterations need consent.
Next door, the Golden Lane Estate, by the same architects, has been inside the City’s boundary since 1994 and includes the Grade II listed Great Arthur House. On the eastern edge, the Middlesex Street Estate was built between 1965 and 1970 and includes Petticoat Tower. Newer residential towers, such as The Heron by Milton Court, add modern high-rise flats to the mix.
In flats of this era, bathrooms and kitchens are stacked above one another, window frames sit in concrete openings and joints move with temperature. A failed shower seal can damage the flat below, so we remove it completely and reseal with flexible sanitary silicone. Our guide to a leaking shower seal explains the warning signs.
Listed estates, managed buildings and controlled access
Almost every job in the City involves a building manager, estate office or concierge. On the Barbican and Golden Lane, the listing means we stick to like-for-like work, replacing failed sealant with a suitable colour and without altering original fittings, and we suggest residents check with the estate office if they’re unsure. In office towers, we book goods lifts, sign in, and follow permit-to-work rules.
There’s very little on-street parking in the Square Mile, so we plan loading and arrival times in advance. High-level flats and offices also have exposed glazing and curtain-wall joints that take more weather than a typical house; where those need specialist access, we’ll say so honestly at the quote stage.
Offices, hotels and healthcare in the Square Mile
More than half a million people work in the City, and the office districts around Bishopsgate, Leadenhall Street and Fenchurch Street have washrooms, showers for cyclists and staff kitchens that see constant use. We reseal these out of hours so offices open as normal the next morning, and we can apply fire-rated sealant where a building’s fire strategy calls for it.
Hotels have opened across the City in recent years, and their guest bathrooms need resealing room by room. St Bartholomew’s Hospital at Smithfield, and the clinics and offices around it, need hygienic joints that are easy to keep clean.
How it works
- Get in touch. Call or email with the job, your postcode and a few photos if you have them.
- Quote and booking. We quote clearly before anything starts and fix a day that works for you.
- Preparation first. Old sealant out completely, surfaces cleaned, mould treated and the joint left dry.
- Lay the new bead. We apply the right product for each joint and tool it to a clean, even line.
- Guaranteed work. You’ll know the cure time before we leave, and every job comes with a one-year guarantee.
What we do in City of London
- Bathroom & kitchen resealing: Mouldy or split sealant around baths, shower trays, basins and sinks removed completely and replaced with a neat, hygienic bead.
- Window & door mastic: Hardened, gappy mastic around frames, sills and French or patio doors cut out and renewed to keep draughts and rain out.
- Commercial & hotel sealant: Commercial washrooms, kitchens and wet areas resealed floor by floor, so only a few rooms are out of use at once.
- Remedial sealant & repairs: Messy, layered or wrong-product sealant cut out and replaced with the right sealant, laid the right way.
- Fire-rated sealant: Fire-rated sealant for service penetrations and frame gaps where it has been specified, applied to the tested details.
- External & façade joints: Expansion joints in brick, render and cladding cut out and renewed at the right depth so they can move without splitting.
- New-build mastic & snagging: Snagging sealant for new homes and plot-by-plot mastic for builders and developers.
- Floor & skirting joints: Floor and skirting joints in homes, shops and warehouses sealed neatly and to the right depth.
- Regrouting: Shower and splashback grout replaced where it has cracked or stained, with silicone in the movement joints.
- Glazing & conservatory sealant: Glazing joints on conservatories, roof lanterns and screens renewed with a sealant suited to glass and frames.
- Gutter, fascia & soffit sealing: Dripping gutter joints and end caps, and gaps at fascias and soffits, sealed with weatherproof exterior sealant.
- Sand mastic for sash & case windows: Traditional burnt sand mastic renewed around sash and case windows and doors in stone and brick.
Why choose Mr Mastic in City of London
Facilities managers and residents in the City need a contractor who turns up when agreed and leaves no mess. That’s how we work. Mr Mastic has over 20 years’ experience, 2,847+ completed projects and a 4.9-star Google rating from more than 180 five-star reviews. We’re fully insured, ARBOMaster approved and use Arbo and Everbuild sealants. You’ll get a clear, written quote before we begin, and the work comes with a one-year guarantee. To arrange a visit, get in touch.
Places we pass in City of London
For trains, London Cannon Street station is closest to the centre. Local landmarks include Gabriel's Wharf (0.8 miles south-west), London Mithraeum (less than half a mile south) and Baynard's Castle (less than half a mile south-west). Closer in, we work on homes, rented flats and businesses near Prior Weston Primary School and Children's Centre, Central Foundation Boys' School, Fashion Retail Academy and St Olave Old Jewry. Nearby green spaces include Barnsbury Wood and Ludgate Hill.
What customers say
Rated 4.9 on Google from 180+ five-star reviews. Read the reviews on Google.
“New build in Forge Wood — shower seal had failed after 16 months. Mr Mastic came out quickly, removed everything and did it properly. Perfect finish and no more leaks.”
“Harper Drive in Maidenbower — kitchen worktop had been leaking behind for a while. Came out the next day, sorted it properly. Really tidy job.”
“Called for a bathroom reseal and the mastic man showed up on time with all the right equipment. Brilliant attention to detail. The sealant looks perfect and they kept everything tidy.”
Neighbourhoods we cover in City of London
Find your area below, or call 07833 053749 or email us with your postcode and a few details.
- Aldgate
- Bankside
- Barbican Estate
- Bishopsgate
- Blackfriars
- Clerkenwell
- Farringdon
- Finsbury
- Smithfield
- Spitalfields
- St Luke's
- Temple
- Temple Bar
- Tower Hill
Other towns around City of London
Questions we’re asked in City of London
Do you cover all of the City of London?
Yes. We cover the whole Square Mile, including the Barbican, Golden Lane, Middlesex Street and Portsoken, Aldersgate, Smithfield, Cheapside, Bishopsgate and the Fenchurch Street area.
Can you reseal a bathroom in a Barbican flat?
Yes. We replace failed sealant like for like, and if you’re unsure whether any part of the work needs consent, check with the estate office before we start.
Can you work in our offices outside business hours?
Yes. Out-of-hours and weekend working can be arranged so washrooms and kitchens are ready when staff arrive.
Do you provide RAMS and work to permit-to-work systems?
Yes. We can supply risk assessments and method statements and follow building management’s permit and sign-in procedures.
Can you reseal hotel bathrooms in the City room by room?
Yes. We work through rooms in batches agreed with the hotel, so each one is back in service once the sealant has cured.
Where do you park in the City?
On-street parking is very limited, so we agree loading arrangements or nearby parking with building management before the visit.
Do you seal around windows in high-rise flats?
We reseal windows and balcony doors that can be reached safely from inside or from a balcony. If a job needs specialist access, we’ll tell you at the quote stage.
Is the work guaranteed?
Yes. Every job comes with our one-year guarantee.