Greater London · England
New-build mastic & snagging in St Giles, Greater London
Plot mastic for developers and snagging failed sealant in new homes for homes and businesses in St Giles and across Greater London. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Kitchen sealant that has pulled off the wall
- Sealant work across a run of new homes
- Cracked caulk along new skirting
New build mastic in St Giles, done properly
Dust is the enemy of new-build sealant. Each joint is cleaned of dust and primed where the product calls for it, so the new bead bonds properly. We work on skirting & floors, kitchens and show homes, and people most often call us about joints pulling apart as timber shrinks and cracked sealant around new window and door frames.
Across London, commercial floors have movement joints that break down under heavy foot traffic, and new homes need their plot mastic finished properly before handover, in St Giles and beyond.
Our work is backed for twelve months.
- Place
- St Giles (W1F, W1D, W1T)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What happens if it’s left?
A tube of sealant from the DIY shop will not fix the cause: dust, no primer and old sealant left in the joint. Cutting out, cleaning and priming are what make the difference. In a flat in St Giles, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
We do not show prices on the website, because the cost depends so much on the job itself. Call for a quick quote and we’ll talk you through it.
What you get with us
- We agree the colour with you first
- Full insurance on every job
- Rated 4.9 stars on Google
- A sealant colour to suit the surroundings
St Giles: your questions answered
Do you work for landlords with property near Tottenham Court Road station?
Yes, landlords and agents are among the people we work for. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Can you do new build mastic in St Giles?
Yes, St Giles is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or email us with a few details of the job, and we will give you a clear quote.
Is it worth resealing while the house is still settling?
Where water is getting through, do not wait. Hairline cosmetic gaps can wait until the house has settled.
Do you have insurance?
Yes, we’re fully insured for domestic and commercial work.
My new home is still under warranty. Should I contact you?
Start with the builder if you are in the snagging or warranty period. If it is not resolved, we can reseal it properly.
Do you work through snagging lists?
Yes. Send it with photos and we’ll quote for the sealant items. If something is not sealant, we will say so.
Are you an approved applicator?
Yes. We hold ARBOMaster approved applicator status and we’re fully insured too.
Is it worth trying it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Also near St Giles
What else we do in St Giles
What new build mastic looks like in St Giles
Much of London’s new housing is flats in larger developments, where snagging may go through the developer or 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.
For new homes near Tottenham Court Road station, it’s worth checking the sealant early, while snags are still fresh.
St Giles is about 1 mile east of City of Westminster, in Greater London. Anywhere in W1F, we can carry out new build mastic at your property. 764 places in Greater London are on our list, large and small.
Work in W1F, W1D and W1T works the same way as everywhere else we cover. Streets in the area include Duck Lane, Drury Lane and Bridle Lane, all of which we cover. St Giles is on the A301 and A400, which makes it straightforward to reach. If you’re just outside St Giles, we cover Seven Dials (1 mile south), West End (1 mile south-west), Soho (1 mile south-west), Covent Garden (1 mile south-east) and Chinatown (1 mile south-west). Within a short drive, we also cover Kensington (3 miles west), Walthamstow (7 miles north-east), Hampstead (4 miles north-west), Ruislip (13 miles west), Stockwell (3 miles south) and Orpington (13 miles south-east).
Near you in St Giles
Typical jobs here are in homes near LSE Shaw Library, The Crown pub and Mercers' School and the streets around them. Also close by are London Nautical School (1 mile south-east) and St Anne's Churchyard (within half a mile south-west). St Giles has its own railway station: Tottenham Court Road station. Nearby you will also find Montfichet's Tower (1.1 miles east) and Kingly Court (0.5 miles west). Green spaces nearby include Barnsbury Wood and Ludgate Hill.
Different surfaces, different methods
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.
Plot handovers
We work through plots to your schedule, sealing each room ready for handover. Each joint is cleaned and primed where needed.
What happens on the day
On the day, there’s very little for you to do. Point us to the joints and we’ll get on with it. The work itself takes a few hours in a single home. In St Giles, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- First, the list of joints is agreed from your snagging sheet or plot schedule.
- Every bit of the old builder’s sealant is cut out down to clean surfaces.
- Joints are vacuumed and cleaned of building dust.
- We prime where needed and apply a sealant suited to each joint.
- We tool every joint neatly and tell you when each area can be used.
How to prepare
- Keep pets and children clear of the area while we work
- Mention any tricky access
- For business premises, tell us about site rules or sign-in
How to get a quote
We do not publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or send us an email.
Advice
What affects the cost of new build mastic
There’s no set price list. What we look at:
- Mould in or behind the old joints
- Any working-time requirements on site
- The number and length of the joints
- How many areas need sealing
Rather than a set price list, we look at what your job involves: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Asking for a quote
Photos help, but a description is a good start. Try to tell us:
- If it’s domestic, commercial or a hotel
- The rough size of the job
- Any previous sealing or DIY work
- Where the property is
For new build mastic in St Giles, call 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you will get a clear quote before any work starts.
Should I try it myself first?
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
Signs you need new build mastic in St Giles
On many sites, sealant goes on in the final rush before handover. Joints aren’t always cleaned of dust or primed, and the sealant sits on grit instead of the surface.
These are the problems we’re asked about most:
- Cracks appearing as a new home settles
- Beads laid onto grit and dust from the build
- Frame joints opening as the plaster dries
- Untidy sealant flagged on a snagging list
As a London address, St Giles can be tricky for parking: let us know about parking bays, permits or a driveway.
Questions to ask before you book
- What the cure time is
- What insurance they hold
- How much experience the applicator has
- How long the guarantee is
Keeping the joints in good condition
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Act quickly if a seal starts to leak
- Report sealant problems to your builder during the snagging period
- Use the extractor fan every time you shower
- Don’t seal over failed sealant yourself
Keep an eye on the joints over the first couple of years. Small gaps can appear as the house dries and can be resealed later.
If a shower tray or bath seal splits in the first year, look for movement. Have it resealed, and the tray or bath checked, before it gets worse.