Greater London · England
New Build Mastic in Smithfield
Professional new build mastic in and around Smithfield, with old sealant always removed completely and a 12-month guarantee.
- Second-fix sealing on new plots
- Sealant that never bonded to the surface
- Shower seals failing in the first year or two
New build mastic for homes and businesses in Smithfield
Some owners wait for the first year’s movement before having joints redone. For small cosmetic gaps, that’s reasonable, but a failed shower or bath seal shouldn’t wait. We are often asked to deal with gaps behind new kitchen upstands and new-build shower sealant that has already split, across skirting & floors, bathrooms & en suites and windows & doors.
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 is covered by a one-year guarantee.
- Location
- Smithfield (EC1V, EC1P, EC1R)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Smithfield questions
Is parking an issue for new build mastic in Smithfield?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Can you help a landlord with a rental near Farringdon station?
Yes, landlords and agents are among the people we work for. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we’ll give you a clear price.
Is it normal for sealant to crack in a new home?
It’s common, and there are normally two reasons: movement as the house dries and settles, and sealant laid onto dust without primer. Cutting it out and resealing properly fixes both.
Is it messy?
Not at all. The area is protected while we work and cleaned up afterwards.
Can you work from my snagging list?
Yes. Photos of each sealant item help us quote. Items that need a plumber, tiler or the builder are flagged.
Is it worth trying it myself?
You can, for simple jobs. 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.
Can you quote for more than one area?
Yes. Several rooms, windows or areas can go on one quote.
Is the work guaranteed?
Yes, for a year. If there’s a problem with our work in that time, tell us and we’ll put it right.
What we do, step by step
There isn’t much for you to do on the day. Point us to the joints and we’ll get on with it. The job generally takes anything from a few hours to several days, depending on the number of plots from start to finish. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Smithfield. It helps if you can point us to a visitor permit or a bay close to the door.
- We start by going through the snagging items or plot schedule with you.
- Every bit of the old builder’s sealant is cut out, with no layer left behind.
- We clean out the dust and grit left from the build.
- Primer goes on where the surface and product need it, then the new sealant.
- Each bead is tooled and the cure times explained.
Getting ready for the visit
- Plan for the work area to be out of bounds to pets and children
- Clear items away from the joints we’re working on
- Let us know about earlier repairs to the joints
How to get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we will talk you through the work.
Read more
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Work for landlords, hotels and businesses
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
For anyone letting property in or around Smithfield, several properties can go on one quote. Send us the addresses and the work at each, and photos by email help.
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
Floors and skirting move as the house dries and the heating runs. Caulk cracks; a flexible sealant moves with it.
Also near Smithfield
Also in Smithfield
Keeping the joints in good condition
How long the joints last depends on use and care. Here’s what we suggest:
- Avoid running a DIY bead over the old one
- Do not wait for the house to settle if water is getting through
- Record problems with dated photos
- Raise failed sealant with the developer while you’re covered
Do not stand on the bath edge or the lip of the tray while the sealant cures. Report any movement in a bath or tray.
Leave a failed new-build seal and water can reach the floor and the ceiling below. Catching it early keeps the fix to the sealant and protects the rest of the house.
New homes and floors in Smithfield
Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Many of London’s new homes are flats in bigger developments, where snags may need reporting through the developer or the managing agent.
As a London address, Smithfield can be tricky for parking: let us know about parking bays, permits or a driveway. For new homes near Farringdon station, it’s worth checking the sealant early, while snags are still fresh.
Smithfield is about 1 mile north of London, in Greater London. We carry out new build mastic for householders, landlords and businesses in Smithfield, as part of our work across Greater London. Our area takes in 764 places across Greater London, large and small.
Here we cover the EC1V, EC1P and EC1R postcode area for new build mastic. Local streets include Oat Lane, Shoe Lane and Long Lane, and we cover them all. Being close to the A1 and A4, Smithfield is simple for us to get to for new build mastic. Close by, we work in Farringdon (1 mile north), Blackfriars (1 mile south), Holborn (1 mile west), Temple Bar (1 mile south-west) and Clerkenwell (1 mile north). Larger places within reach include Kensington (4 miles west), Walthamstow (6 miles north-east), Hampstead (4 miles north-west), Ruislip (14 miles west), Brompton (3 miles south-west) and Stockwell (4 miles south).
Landmarks near Smithfield
Locally, jobs take us to homes and businesses close to London Nautical School, Barts Health Archives and St Alban's Church of England Primary School and the streets around them. You will also find St Mary-at-Hill (1 mile south-east), Oriole pub (within half a mile south-west) and Postman's Park (less than half a mile south-east). Smithfield has its own railway station: Farringdon station. Nearby you will also find Montfichet's Tower (less than half a mile south) and Postal Museum (less than half a mile south-east). The countryside around Smithfield includes Ludgate Hill and St. James's Park Lake.
What affects the cost of new build mastic
Some jobs are bigger than they look, and some smaller. The main factors:
- The number and length of the joints
- The number of rooms or windows
- Any mould that needs treating
- Any working-time requirements on site
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all play a part.
Asking for a quote
To help us quote quickly, let us know:
- Roughly how big the job is
- Any access issues, like height or stairs
- Where the property is
- Photos by email, if that is easy
If you’re in Smithfield and need new build mastic, ring 0345 464 0079 or send us an email. Tell us what the problem is and where, and you will get a clear quote before any work starts.
When something else is needed
A few problems are outside what sealant work can do:
- Settlement cracks that need a surveyor
- Movement caused by a poorly fitted tray or bath
- Plumbing faults behind the sealant
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
What we seal
- Plot handovers
- Windows & doors
- Skirting & floors
- Show homes
- Kitchens
- Bathrooms & en suites