City of London · England
New-build mastic & snagging in City of London
New-build sealant joints in City of London need attention? We cut out the old, prepare the joints and apply the right sealant, with a one-year guarantee.
- Second-fix sealing on new plots
- Shower seals failing in the first year or two
- Cracked sealant around new window and door frames
Questions from City of London
Is City of London in your area for new build mastic?
Yes. Our work covers London and the South East, and City of London is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear price.
Can you help a landlord with a rental near London Cannon Street station?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can go on one quote. Just call 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear price.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. Once we have agreed the job, you don’t need to watch us work.
How do I get a quote for new build mastic in City of London?
There’s no set price, as it depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
Can I send you my snagging list?
Yes. Snagging lists are a common starting point for us. We will go through the sealant items and agree what we will do.
Can you do plot mastic on a new development?
Yes. Second-fix sealing in bathrooms, kitchens, frames and floors is part of what we do. Good preparation keeps snagging to a minimum.
Where are you based?
We work from Crawley. Our applicators cover City of London, along with the rest of our area.
Are you ARBOMaster approved?
Yes. We are approved under the ARBOMaster scheme, the approved applicator scheme for Arbo sealants.
About our new build mastic in City of London
We work in new homes and on new-build sites across City of London. One shower or a whole phase of plots, the method doesn’t change: cut out, clean, prime where needed and reseal neatly. Common call-outs are for gaps behind new kitchen upstands and shower seals failing in the first year or two, across kitchens, plot handovers and show homes.
New flats are going up across London, many of them in larger developments. Snagging there often goes through the developer or managing agent, and failed shower seals, open skirting joints and gaps at thresholds are typical.
All our work comes with a one-year guarantee.
- Place
- City of London (EC4V, EC1A, EC2M, EC2Y)
- Wider area
- City of London
- Cover
- A year, on every job
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Work for landlords, hotels and businesses
We also work for property managers and facilities teams in City of London. Several sites can be quoted together, and we’re fully insured.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Also near City of London
Also in City of London
What sealant work can’t fix
We’ll always be straight with you, so here’s what new sealant will not do:
- Broken tiles or a split tray
- Leaking fittings rather than failed sealant
- Settlement cracks that need a surveyor
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly before you book.
Joints and surfaces we work on
- Bathrooms & en suites
- Windows & doors
- Plot handovers
- Kitchens
- Skirting & floors
- Show homes
What happens on the day
At the end, we look at the finished work together. The work normally takes a few hours in a single home, depending on the amount of work. In City of London, 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.
- Each joint is checked for movement before any work starts.
- We remove the failed sealant and clean the joints.
- Joints are dried and primed where the product calls for it.
- Baths are filled with water, then the new sealant is applied.
- The finished joints are checked and the cure times given.
Before we arrive
- Let us know about earlier repairs to the joints
- Tell us if parking is tricky
- Mention any sign-in or site rules at work premises
Get a quote
We don’t publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To arrange one, phone 0345 464 0079 or drop us an email.
Related advice
Surface by surface
Windows and doors
Draughts around new frames are often a sealant gap. We look at the joints and reseal where needed.
Skirting and floors
Where the floor meets a bath panel or kitchen plinth, the joint keeps mop water out. They get a flexible, water-resistant sealant.
How we quote for new build mastic
For a quick quote, just ask. The main things that affect it are:
- The old material and how stubborn it is
- The amount of work
- The product the joint needs
- When we can work, for business premises
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
What to tell us for a quote
You do not need to know the technical terms. It helps if you can tell us:
- What the problem is, such as mould, gaps, leaks or cracking
- The rough size of the job
- Where the property is
- A few photos by email, if you can
For a quote, call 0345 464 0079 or email us with the location and a short description of the problem. You’ll have a clear quote before we start.
Joints and finishes in City of London homes
Much of London’s new housing is flats in larger developments, where snags may need reporting through the developer or the managing agent. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you’ve bought a new home near London Cannon Street station, the sealant around baths, showers and frames is worth checking in the first year or two. As a London address, City of London can be tricky for parking: let us know about parking bays, permits or a driveway.
City of London is about 1 mile north of London, in City of London. Homes, rented property, offices and hotels in City of London can book us for new build mastic, old or new, large or small. The work is guaranteed for a year.
Here we cover the EC4V, EC1A, EC2M and EC2Y postcode area for new build mastic. New build mastic is available to properties on Aldermanbury Square, Monkwell Square and Paternoster Square. City of London is on the A1 and A3, so it’s easy for us to get to with everything needed for new build mastic. We also cover the places around City of London: Barbican Estate (1 mile north), Bishopsgate (1 mile east), Finsbury (1 mile north), Aldgate (1 mile east) and St Luke's (1 mile north).
Local landmarks in City of London
Typical jobs here are in homes near St Mary-at-Hill, Prior Weston Primary School and Children's Centre and Golden Fleece pub and the streets around them. Nearby too are Central Foundation Boys' School (0.8 miles north), Barts Health Archives (within half a mile north-west) and St Alphage Garden (under half a mile north). City of London has its own railway station: London Cannon Street station. Well-known places in the area include Gabriel's Wharf (0.8 miles south-west) and London Mithraeum (less than half a mile south). For a walk, there’s St. James's Park Lake and Barnsbury Wood.
Aftercare tips
How long the joints last depends on use and care. We suggest:
- Keep water off fresh sealant until it has cured
- Watch for new gaps as the house dries out
- Act quickly if a seal starts to leak
- Clean sealant with mild detergent, not abrasives
Follow the cure time we give you before the area gets wet. Most silicones need around a day to cure enough for use.
The sooner you deal with untidy or cracking sealant, the less there is to put right. Small faults turn into leaks if left in a busy bathroom.
Why deal with it now?
Sealant done properly at handover means fewer callbacks. Snagging visits for failed sealant cost time on every plot and most come down to preparation. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in City of London, the repair is bigger than a sealant job.
Combining jobs into one visit is normally more efficient than separate visits, so it’s worth mentioning everything you’d like done. You will get one clear quote for the whole job.
Why us?
- You choose the colour before work begins
- We leave the area clean and tidy
- 180+ five-star Google reviews
- A 12-month guarantee on all work