Mastic sealing for building owners and managing agents in City of London
Planning work on a mastic joint in City of London? We assess it, carry out the work and guarantee our workmanship for 12 months.
- The same joint failures repeated across a portfolio
- Movement joints with sealant missing
- Patchy repairs in mismatched sealant
Mastic sealing near City of London
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
Work for main contractors and building owners
CHAS accredited and a Constructionline member, we make supplier vetting simple. We are fully insured, and our insurance certificate can go with the quote.
Agents, factors and owners’ representatives all follow the same route: send the details, accept a fixed quote, and we carry out and guarantee the work. We can agree access arrangements and keyholder contacts beforehand.
How we handle mastic sealing in City of London
Before work starts, most agents and landlords want the documents in order. For documents, tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we’ll confirm with the quote. We are CHAS accredited and a Constructionline member, with public liability insurance. We work on communal kitchens and washrooms, balcony and threshold joints and window and door perimeters on blocks, and the failures we are asked to look at most are the same joint failures repeated across a portfolio and old repairs sealed over failed mastic. Looking for mastic applicators who cover City of London? We’ve been sealing commercial buildings since 2005, CHAS accredited and a Constructionline member.
London has a large stock of purpose-built blocks, mansion flats and converted buildings managed by agents and housing associations. Mastic around windows, doors and balconies tends to fail across a whole block at a similar time.
We stand by our work: 12 months, guaranteed. That covers our preparation and application, and we come back if anything isn’t right.
- Place
- City of London (EC4V, EC1A, EC2M, EC2Y)
- Region
- City of London
- Guarantee
- 12 months on every job
- Price
- Fixed quote, scope in writing
- Phone
- 01277 525 020
- Updated
- 3 November 2026
Why it’s worth doing now in City of London
Leaving failed external joints lets water reach the structure behind. Damp patches, stained plaster and decorating claims can follow, which is harder to deal with than resealing. In a London building, a failed joint rarely affects only one party: water travels through shared structures, and a small leak becomes a dispute between occupiers. Putting it right early is less disruptive than dealing with the consequences.
The price depends on how many linear metres there are, how much old material needs removing and the access. Call for a quote when you are ready.
Why clients in City of London choose us
- Colour options checked against the specified product
- Health and safety: CHAS accredited
- Workmanship guaranteed for 12 months
- Failed material removed, not covered up
Take a look at how commercial sealant jobs are priced and our accreditations and insurance.
Looking after the joints
Problems stay small when the joints are checked regularly. In particular:
- Share your contractor requirements early
- Make mastic part of routine maintenance checks
- Reduce knocks to communal area joints
- Have the asbestos survey to hand for older buildings
Log the date and extent of the resealing for each block. That makes future programmes easier to plan and gives you a history.
Leaks at window perimeters spoil finishes and can affect frames. Early resealing is far simpler than repairs inside.
Your questions answered
Do you cover business parks and estates near City of London, such as Southwark Bridge Business Centre?
Yes. Estates, retail parks and business parks around City of London, Southwark Bridge Business Centre among them, are all within reach. Send details of the unit and the work through our quote form for a quick quote.
Can you quote for a block close to London Cannon Street station?
Yes. Managing agents, landlords, property factors and housing associations are who this service is for. We work to your notice and access arrangements.
Can you take on resealing for a block portfolio?
We do. Managing agents, property factors in Scotland, housing associations and landlords with block or commercial portfolios are our main clients for this work and work can be quoted per building or as a whole.
What if the old mastic contains asbestos?
Some mastics in pre-2000 buildings contain asbestos. We ask for the asbestos register or survey before work starts and suspect material is tested first.
Can you work to our specification?
Yes. The specification and the manufacturer’s installation guidance are what we work to.
What paperwork can you provide?
Tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we’ll confirm with the quote. We are CHAS accredited and a Constructionline member.
What about access for upper-floor joints?
We talk through access for each building when we quote. Tell us the building height and any access already in place and we will confirm the approach in the quote.
Nearby places to City of London
What else we do in City of London
From enquiry to sign-off
We begin with a short walk round with whoever looks after the building, agreeing which joints are in scope, where to start and what must stay open. After that, any old or failed material is removed, each joint is prepared and the new sealant goes in. The ULEZ covers the whole of Greater London, and parking near a job is rarely simple. Let us know about any on-site parking or loading arrangements when you send the job details.
- We check the asbestos register for older buildings and look at the joints.
- The products and programme are set out in a fixed quote.
- Failed mastic is removed completely.
- Joint faces are cleaned, backed and resealed.
- We finish each building before moving to the next.
Preparing the site
- Send any specification or drawings in advance
- Move anything stored against the joints
- Share your working hours and any access restrictions
Request a quote
Let us know the site, the scope and your timescale, and we will put a fixed quote together. The easiest way is to call 01277 525 020 or email us.
Advice
Doing it in-house
Site maintenance staff can often handle a short internal joint. The usual problems come from preparation: sealing over old material, sealing onto damp or dusty surfaces, or a product that can’t take the movement.
Some joints are best left to specialists: for example fire-rated seals that must match a tested detail, trafficked floor joints and external movement joints. A poor seal in places like these tends to cost more to put right later.
Cost factors for mastic joints
Quotes vary with the job. Expect it to depend on:
- Travel to remote or island sites
- How accessible the joints are
- The site’s rules and procedures
- Which sealant the job calls for
We don’t publish prices, because the scope varies so much from one building to the next. Call for a quote and we’ll price your job on its own details.
What we need to price the job
The more we know, the firmer the quote. When you get in touch, include:
- When you need the work done
- Any specification or named product
- The postcode of the building
- Drawings or a marked-up plan, if available
Send us photographs, drawings or a joint schedule and a fixed quote comes back to you. Where a site visit makes more sense, we’ll arrange one.
Mastic sealing in City of London: the local picture
For a London block, the agent or landlord typically handles notices to residents and access to flats. We work to your notice and access plan. The 2 miles around City of London include three care or nursing homes. For owners and operators of care buildings, window perimeters and external joints are best renewed in planned phases around residents.
If your remit includes a building such as Fashion Retail Academy, frame and door mastic can be programmed for the holidays. Churches, halls and community buildings such as St Olave Old Jewry are looked after by trustees and committees like any other owner, and their frames, doors and external joints need mastic renewed in time. Landlords with units on estates such as Southwark Bridge Business Centre (0.8 miles south of City of London) can bring frame, door and external mastic across several units into one programme.
City of London is about 1 mile north of London, in City of London. If you’re looking for mastic sealing in City of London, we can help, as we do across City of London. Our City of London coverage takes in 7 places, from busy centres to rural villages.
Postcode districts covered here: EC4V, EC1A, EC2M and EC2Y. We cover commercial and managed buildings on Aldermanbury Square, Monkwell Square and Paternoster Square and the roads nearby. Access to City of London is via the A1 and A3 among other routes. If your building is just outside City of London, we cover Barbican Estate (1 mile north), Bishopsgate (1 mile east), Finsbury (1 mile north), Aldgate (1 mile east) and St Luke's (1 mile north).
Around City of London
Recent enquiries here include premises near St Mary-at-Hill, Prior Weston Primary School and Children's Centre and Golden Fleece pub, among other places. Nearby too are Central Foundation Boys' School (0.8 miles north), Barts Health Archives (less than half a mile north-west) and St Alphage Garden (under half a mile north). There’s a railway station in City of London itself: London Cannon Street station. Nearby you will also find Gabriel's Wharf (0.8 miles south-west) and London Mithraeum (under half a mile south). Open spaces near City of London include St. James's Park Lake and Barnsbury Wood.