Greater London · England
New Build Mastic in St Helier
Specialist new build mastic for St Helier: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Internal frame sealant that has split
- Second-fix sealing on new plots
- Skirting joints opening in the first winter
New build mastic in St Helier, done properly
For builders and developers, we work through plots to the schedule you give us. Bathrooms, en suites, kitchens, frames and skirting are sealed ready for handover with a sealant suited to each area. We work on kitchens, bathrooms & en suites and windows & doors, and people most often call us about sealant applied over dusty or wet surfaces and new-build shower sealant that has already split.
New flats are going up across London, many of them in larger developments. In a new development, snags are often reported through the developer or the managing agent, and failed shower seals, open skirting joints and gaps at thresholds are typical.
All of our work is guaranteed for twelve months, and the guarantee is the same wherever you are.
- Place
- St Helier (SM5, SM4, SM1)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
When it is not the sealant
New sealant cannot fix everything, and we will tell you before we start. Sealant will not put right:
- Movement caused by a poorly fitted tray or bath
- Settlement cracks that need a surveyor
- Damaged fittings that need replacing
If in doubt, ring 0345 464 0079 or email us and we will say what we think.
What we seal
- Windows & doors
- Show homes
- Kitchens
- Bathrooms & en suites
- Plot handovers
- Skirting & floors
New homes and floors in St Helier
Much of London’s new housing is flats in larger developments, where snags may need reporting through the developer or the managing agent. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you’ve bought a new home near Sutton Common station, the sealant around baths, showers and frames is worth checking in the first year or two. St Helier is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
St Helier is about 3 miles south-east of Wimbledon, in Greater London. Across the SM5 area, we can carry out new build mastic at your property. Our area takes in 764 places across Greater London. London is on our list too, about 9 miles from St Helier.
Work in SM5, SM4 and SM1 is quoted and booked the same way as anywhere else. You’ll find streets such as Kelso Road, Wrythe Lane and Whitby Road, all of which we cover. Close by, we work in Rosehill (1 mile north-east), Benhilton (1 mile south-west), The Wrythe (1 mile south-east), Carshalton (1 mile south-east) and Sutton (1 mile south). Within a short drive, we also cover London (9 miles north-east), City of Westminster (9 miles north), Marylebone (9 miles north), Kensington (8 miles north), St Pancras (10 miles north) and Shoreditch (11 miles north-east).
Local landmarks in St Helier
Locally, jobs take us to homes and businesses close to Greenshaw High School, The Cricketers Inn and Merton College, among other places. The closest station to St Helier is Sutton Common station, about 0.8 miles south-west. Well-known places in the area include St Helier Hospital (less than half a mile south) and Chessington Castle Hill (5 miles west). Not far away are Bennett's Hole and Duppas Hill.
Looking after it afterwards
To keep the joints looking good and working properly:
- Wait for the cure time before using a resealed shower
- Avoid running a DIY bead over the old one
- Record problems with dated photos
- Watch for new gaps as the house dries out
Avoid standing on the rim of the bath or the edge of the tray while the sealant cures. Report any movement in a bath or tray.
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.
Work for landlords, hotels and businesses
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
We also work for property managers and facilities teams. We can quote a run of properties together, and we are fully insured for the work.
Why act early in St Helier
A tube of sealant from the DIY shop will not fix the cause: grit, unprimed surfaces and old layers underneath. Proper removal and preparation are what make it last. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Dealing with it early is far simpler.
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why us?
- Old sealant always removed completely
- You choose the colour before work begins
- A sealant colour to suit the surroundings
- Tidy, careful work
Take a look at how sealant jobs are priced or customer reviews.
How it works
We bring everything the job needs with us, so you don’t need to buy or prepare anything. After a quick look at the joints together, we protect the area and start. It normally takes a few hours in a single home. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We look at why each joint failed, including any movement.
- Old sealant is cut out and the joints cleaned.
- We make sure the joints are dry and prime them if needed.
- New sealant goes in, with baths filled first so they’re at their heaviest.
- The finished joints are checked and the cure times given.
Before we arrive
- Let us know about parking restrictions
- Tell us about access, such as stairs, a lift or high-level joints
- Tell us about any water getting in
Ask for a quote
Need a quote? Please phone 0345 464 0079 or email us and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Related advice
St Helier questions
Is parking an issue for new build mastic in St Helier?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Do you cover St Helier for new build mastic?
Yes, St Helier is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or email us and tell us what needs doing, and we’ll give you a clear quote.
When is the best time to reseal in a new build?
Where water is getting through, don’t wait. Small gaps that are just cosmetic can be resealed once movement has slowed.
Is there any odour?
Sometimes, a little. Any smell clears as the sealant cures.
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.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Do you do commercial work?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
Do you have insurance?
Yes. We are fully insured, and we can confirm the details when we quote.
Towns and villages near St Helier
Also in St Helier
What the job involves on each surface
Skirting and floors
New homes often develop a gap between skirting and floor. A flexible sealant closes it without cracking like caulk.
Plot handovers
We work through plots to your schedule, sealing each room ready for handover. Each joint is cleaned and primed where needed so the sealant lasts.
How we quote for new build mastic
For a quick quote, just ask. The main things that affect it are:
- How easy the joints are to reach
- Any working-time requirements on site
- Whether there’s mould to deal with
- How much old sealant there is and how hard it is to remove
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote and we will talk you through it.
What we need to know
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Where the property is
- Whether it has been sealed before
- Access, such as stairs, a lift or height
- How many joints, rooms or windows are involved
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we’ll talk you through the work.