Greater London · England
New-build mastic & snagging in Clerkenwell, Greater London
Specialist new build mastic for Clerkenwell: careful preparation, the right product and tidy work. Call for a quick quote.
- Worktop and upstand sealant coming away
- Second-fix sealing on new plots
- Messy sealant that spoils new finishes
About our new build mastic in Clerkenwell
Dust is the enemy of new-build sealant. Each joint is cleaned of dust and primed where the product calls for it, so the sealant actually sticks instead of bonding to the dust. If you are dealing with new-build shower sealant that has already split and gaps opening as the house dries out and settles, we can put it right, whatever the surface.
Shops, offices and commercial units across London have hard-wearing floors with movement joints that need resealing as they wear, while new homes need a neat, sound finish around frames, baths and kitchens before handover.
All of our work is guaranteed for twelve months, in Clerkenwell and everywhere else we cover.
- Where
- Clerkenwell (N1, EC1V, WC1X)
- Region
- Greater London
- Cover
- A year, on every job
- Price
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Clerkenwell questions
I let a flat near Farringdon station. Can you help?
Yes. We work for landlords and letting agents as well as homeowners. Just call 0345 464 0079 or email us with the address and what needs doing, and we will send you a clear quote.
Do you cover Clerkenwell for new build mastic?
Yes, Clerkenwell is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job.
Is there any odour?
Possibly a little. It fades as the sealant cures.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Is it worth resealing while the house is still settling?
For failed seals that let water through, the best time is now. For small cosmetic gaps, waiting until the house has settled can save doing them twice.
Which products do you use?
We choose the sealant for the joint, not the other way round. Where it moves, gets wet or faces the weather makes a difference, and we will tell you what we’re using.
Does someone need to be in?
If the work is inside, we need someone to let us in. Once we’ve agreed the job, you don’t need to watch us work.
Is it worth trying it myself?
It depends on the job. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
Quotes for new build mastic in Clerkenwell
We do not publish a price list. What we look at:
- Any mould that needs treating
- Any working-time requirements on site
- Whether old sealant or filler has to be cut out
- Whether the work is at height
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
What we need to know
To make quoting easier, let us know:
- Photos by email, if that’s easy
- What’s wrong with the joints now
- Roughly how big the job is
- Whether it’s a home or a business
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.
DIY versus a professional finish
If you’ve already had a go yourself, that is fine. We cut it out and start again.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
New build mastic around Clerkenwell
Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Much of London’s new housing is flats in larger developments, where snagging may go through the developer or managing agent.
For new homes near Farringdon station, it’s worth checking the sealant early, while snags are still fresh.
Clerkenwell is about 2 miles north of London, in Greater London. Jobs in Clerkenwell get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Our Greater London coverage runs to 764 places, and Clerkenwell is one of them.
Here we cover the N1, EC1V and WC1X postcode area for new build mastic. Whether your property is on Long Lane, City Road and Noel Road or a nearby road, our applicators can take on the job. With the A1 and A5201 close by, Clerkenwell is easy for our applicators to reach. We also cover the places around Clerkenwell: Farringdon (1 mile south), Angel (1 mile north), Smithfield (1 mile south), Holborn (1 mile south-west) and St Pancras (1 mile west). Further out, we also cover Kensington (5 miles south-west), Walthamstow (5 miles north-east), Hampstead (4 miles north-west), Ruislip (14 miles west), Brompton (3 miles south-west) and Stockwell (4 miles south).
Near you in Clerkenwell
Typical jobs here are in homes near Barts Health Archives, The Sekforde pub and Elizabeth Garrett Anderson School, among other places. You will also find Tech City College (within half a mile north-east) and King Square Gardens (less than half a mile north-east). There’s a railway station in Clerkenwell itself: Farringdon station. Well-known places in the area include Brunswick Centre (0.9 miles west) and Montfichet's Tower (0.9 miles south). Open spaces near Clerkenwell include St. James's Park Lake and Ludgate Hill.
Aftercare tips
Joint life depends on how it’s used and looked after. We suggest:
- Look at the sealant regularly in the first couple of years
- Resist patching a failed seal with a tube from the DIY shop
- Photograph failed sealant before it’s redone
- Wipe joints with warm soapy water
Ventilation matters in a new home, which is still drying out. Use the extractor fan or open a window after showers to help keep mould away.
The sooner you deal with untidy or cracking sealant, the less there is to put right. Left alone, a small crack can become a leak over time.
What we do, step by step
On the day, there’s very little for you to do. Show us the job and we will take it from there. The work itself takes a few hours in a single home, including the tidy-up. In Clerkenwell, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- First, the list of joints is agreed from your snagging sheet or plot schedule.
- The failed sealant is removed completely, 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.
- We tool every joint neatly and tell you when each area can be used.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- Mention any leaks or damp you’ve noticed
- Try not to wet indoor joints just before the visit
How to get a quote
Want a quote for new build mastic? Please ring 0345 464 0079 or email us and tell us about the job. We will explain what we’d do and give you a clear quote before we start.
Related advice
Towns and villages near Clerkenwell
What else we do in Clerkenwell
How the job changes by surface
Plot handovers
Good preparation at handover saves snagging later. Dust from the build is removed first.
Kitchens
New-kitchen sealant is often applied in a rush. We remove it and reseal with a kitchen-suitable sealant.
What we are called out for in Clerkenwell
New homes are full of moisture from plaster, screed and concrete, and it dries out over the first couple of years. Drying timber shrinks and pulls joints apart and the sealant has to cope with the movement.
It’s worth asking for a quote if you see:
- Untidy sealant flagged on a snagging list
- Joints pulling apart as timber shrinks
- Internal frame sealant that has split
- Skirting joints opening in the first winter
As a London address, Clerkenwell can be tricky for parking: let us know about parking bays, permits or a driveway.
Comparing quotes
- Whether all the old sealant comes out first
- What the cure time is
- Who turns up on the day
- What the quote includes, VAT included or not
When something else is needed
New sealant can’t fix everything, and we’d rather say so up front. It will not solve:
- Disputes or warranty claims with your builder
- Structural cracks in walls or ceilings
- Damaged fittings that need replacing
Not sure which it is? You can phone 0345 464 0079 or send us an email and we’ll tell you honestly.
What we seal
- Skirting & floors
- Plot handovers
- Bathrooms & en suites
- Kitchens
- Show homes
- Windows & doors