Greater London · England
New-build mastic & snagging in London, Greater London
New build mastic in London from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Joints pulling apart as timber shrinks
- Worktop and upstand sealant coming away
- Internal frame sealant that has split
How we handle new build mastic in London
We carry out plot mastic and second-fix sealing for builders, and snagging reseals for new-home owners. In both, preparation makes the difference, because that’s what rushed new-build sealant generally lacks. If you’re dealing with cracked caulk along new skirting and joints pulling apart as timber shrinks, we can put it right, whatever the surface.
Around a large town like London, business units and warehouses have concrete floors with sawn joints that break down under traffic. Homes need the same attention on a smaller scale, from skirting joints to shower seals.
All our work is covered by a one-year guarantee, wherever you are in Greater London.
- Place
- London (CR0, E14, CR4, SW11)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Landlord and commercial work in London
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we will quote.
We work for landlords and agents as well as householders. Resealing between tenancies keeps a property looking cared for.
What sealant work can’t fix
To be straight with you, there are a few things sealant won’t fix:
- Leaks from pipes, valves or wastes, which need a plumber
- Structural cracks in walls or ceilings
- Your warranty claim itself, which is between you and the builder
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly.
Where we work in London
- Skirting & floors
- Bathrooms & en suites
- Windows & doors
- Kitchens
- Show homes
- Plot handovers
Different surfaces, different methods
Kitchens
As a new house dries, worktops and walls shift a little, opening gaps behind the upstand. We reseal them with a flexible sealant.
Windows and doors
A draught at a new window can be a missed or failed joint. We look at the joints and reseal where needed.
What we do, step by step
You do not need to clear the whole room or building before we come, just the space around the work. We protect the rest, and the job takes a few hours for most snagging lists, longer for a run of plots in most cases. Where a business in London needs to stay open, out-of-hours working can be arranged, while home visits are arranged within our normal working hours, Monday to Saturday.
- We look at why each joint failed, including any movement.
- We remove the failed sealant and clean the joints.
- We make sure the joints are dry and prime them if needed.
- Baths are filled with water, then the new sealant is applied.
- The finished joints are checked and the cure times given.
How to prepare
- Let us know about stairs, lifts or work at height
- Keep pets and children clear of the area while we work
- Clear items away from the joints we are working on
Ask for a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.
Related advice
What affects the cost of new build mastic
You will get a clear quote before any work starts. It’s based on:
- Working hours on commercial sites
- The number of rooms or windows
- Any mould that needs treating
- How easy the joints are to reach
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, call 0345 464 0079 or send us an email and we will give you an honest view and a quote.
Asking for a quote
Photos by email are helpful but not essential. Try to tell us:
- A few pictures by email, if you can
- Where the job is, and your postcode
- What’s wrong with the joints now
- Whether it has been sealed before
Asking for a quote is easy: let us know what needs doing and where and its rough size. Photos by email help us understand the job.
How to look after the new joints
After the cure time, these simple habits help:
- Open a window or run the fan after bathing
- Get a leaking seal dealt with straight away
- Don’t seal over failed sealant yourself
- Follow the cure time we give you
Leave the sealant for the cure time we give you before showering or bathing. Most silicones need around a day before water reaches them.
The sooner you deal with untidy or cracking sealant, the less there is to put right. Small faults turn into leaks if left.
London: your questions answered
Can you help a landlord with a rental near Elephant & Castle station?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before we start.
Can you do new build mastic in London?
Yes. Our work covers London and the South East, and London is part of that. You can ring 0345 464 0079 or send us an email and let us know what needs doing.
Do I have to be there?
If the work is inside, we need someone to let us in. Once we have agreed the job, you do not need to watch us work.
Can new sealant go on top of the old bead?
No. New silicone will not bond to old silicone, so it soon lifts and traps water. The old sealant always comes out first.
Can you do several jobs on one visit?
Yes. Just list everything you need.
What do you need from me for a quote?
A short description and the location, plus pictures if you have them. If we need more, we’ll ask.
Are you an approved applicator?
Yes. We’re approved under the ARBOMaster scheme.
Do you have insurance?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Places near London
Also in London
When to call us in London
Not every new-build joint gets the right sealant: caulk where water collects, or a rigid product on a moving joint. Both fail early.
The problems people generally mention when they call include:
- Internal frame sealant that has split
- Gaps opening as the house dries out and settles
- Kitchen sealant that has pulled off the wall
- Gaps between new skirting and floors
In and around London, as anywhere, good new build mastic starts with a clean, dry, properly prepared joint.
What to look for in a quote
- Whether they seal over old material or remove it
- Whether VAT is included
- Who does the work, and how experienced they are
- How long to leave it before use
Joints and finishes in London homes
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you’ve bought a new home near Elephant & Castle station, the sealant around baths, showers and frames is worth checking in the first year or two.
London is in Greater London. We carry out new build mastic for householders, landlords and businesses in London and the surrounding area. Across Greater London, we cover 764 places, London among them.
We work across CR0, E14, CR4 and SW11 for new build mastic and the streets around it. New build mastic is available to properties on Walcot Square, Surrey Square and Sutherland Square. London is on the A2 and A10, which makes it straightforward to reach with everything needed for new build mastic. Close by, we work in Walworth (1 mile south), Bermondsey (1 mile east), Camberwell (2 miles south), South Bermondsey (2 miles south-east) and Surrey Canal (2 miles south-east). Further out, we also cover City of Westminster (3 miles west), Marylebone (3 miles north-west), Kensington (5 miles west), Walthamstow (7 miles north-east), Hampstead (5 miles north-west) and Ruislip (14 miles west). As one of the bigger places in Greater London, London has every kind of property, from flats to offices.
Near you in London
Typical jobs here are in homes near Newington Gardens, Trinity Arms Public House and London School of Musical Theatre. Other local landmarks include St Mary-at-Hill (0.9 miles north-east), Ark Globe Academy (less than half a mile south) and The BFI Reuben Library (1 mile north-west). London has its own railway station: Elephant & Castle station. A little further out are Surrey Dispensary (under half a mile south-east) and Baynard's Castle (0.9 miles north). Not far away are Bellenden Road Nature Garden and St. James's Park Lake.