Greater London · England
Netherne on-the-Hill New Build Mastic
Plot mastic for developers and snagging failed sealant in new homes for Netherne on-the-Hill, backed by a 12-month guarantee. Ask us for a quote.
- Kitchen sealant that has pulled off the wall
- Internal frame sealant that has split
- Gaps opening as the house dries out and settles
How we handle new build mastic in Netherne on-the-Hill
A new house keeps drying out and settling for its first couple of years. Timber dries and shrinks, and baths and trays settle, and sealant applied in a hurry at handover can split. Typical jobs include sealant work across a run of new homes and gaps between new skirting and floors, across bathrooms & en suites, plot handovers and windows & doors.
From brand-new flats to converted terraces with new flooring, London has every kind of floor. Every joint between floor, skirting and threshold has to cope with some movement, in Netherne on-the-Hill as anywhere.
There’s a 12-month guarantee on every job, large or small.
- Where
- Netherne on-the-Hill (CR5)
- Region
- Greater London
- Cover
- A year, on every job
- Quote
- A clear price before we start
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
New homes and floors in Netherne on-the-Hill
Much of London’s new housing is flats in larger developments, where snags may need reporting through the developer or the managing agent. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For new homes near Coulsdon South station, it’s worth checking the sealant early, while snags are still fresh.
Netherne on-the-Hill is about 2 miles south of Coulsdon, in Greater London. Whether you’re in the middle of Netherne on-the-Hill or further out, we cover new build mastic for every kind of property, from flats and houses to offices and hotels. Across Greater London, we cover 764 places, and Netherne on-the-Hill is one of them. We also work in Crawley, about 13 miles from Netherne on-the-Hill.
Work in CR5 is quoted and booked the same way as anywhere else. We cover properties on The Village Square, Rookery Mead and Netherne Lane and the roads around them. Other places close to Netherne on-the-Hill include Hooley (1 mile west), Merstham (2 miles south), Chaldon (2 miles south-east), South Merstham (2 miles south) and Gatton (2 miles south-west). Larger places within reach include London (14 miles north), City of Westminster (15 miles north), Kensington (15 miles north), Brompton (14 miles north), Stockwell (12 miles north) and Orpington (12 miles north-east).
What’s near Netherne on-the-Hill
In Netherne on-the-Hill, that means homes and buildings near Shabden Park. Netherne on-the-Hill’s nearest station is Coulsdon South station, about 1.6 miles north. A little further out are The Belfry (3.8 miles south) and East Surrey Museum (2.9 miles east). Not far away are South London Downs National Nature Reserve and Colley Hill.
Signs you need new build mastic in Netherne on-the-Hill
If plaster or screed was still damp when it was sealed, the bond suffers. Site programmes don’t always leave time for joints to dry.
The problems people generally mention when they call include:
- Gaps behind new kitchen upstands
- Internal frame sealant that has split
- Leaking shower tray seals in a new home
- Gaps opening as the house dries out and settles
As a London address, Netherne on-the-Hill can be tricky for parking: let us know about parking bays, permits or a driveway.
Questions to ask before booking
- Which colour the sealant will be
- How the surfaces are prepared before sealing
- What product goes in the joint
- How much experience the applicator has
Should I try it myself first?
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
Landlords, agents and businesses in Netherne on-the-Hill
We also work for property managers and facilities teams in Netherne on-the-Hill and across Greater London. Several sites can be quoted together, and we are fully insured for the work.
For anyone letting property in or around Netherne on-the-Hill, several properties can be quoted together. Send us the addresses and the work at each, and pictures by email help.
What else we do in Netherne on-the-Hill
Surface by surface
Bathrooms and en suites
New-build bathrooms and en suites are where sealant fails most often. We cut out the failed bead, clean and prime, and reseal with anti-fungal sanitary silicone.
Windows and doors
On new builds, external frame sealant can be patchy. We reseal it with a weatherproof, flexible sealant.
Aftercare tips
A little care helps the new joints last. We recommend:
- Avoid scourers and strong chemicals on sealant
- Record problems with dated pictures
- Ventilate bathrooms well, especially in the first year
- Do not seal over failed sealant yourself
Follow the cure time we give you before the area gets wet. Silicone is usually left for about a day before water reaches them.
A failed seal in a new home lets water into joists, plasterboard and ceilings. Catching it early keeps the fix to the sealant.
The process
Before we leave, we go over the finished joints with you and tell you how long to leave it. The work normally takes a few hours in a single home, depending on the size of the job. 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.
- 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.
- We check every joint and leave you with the cure times.
Before we arrive
- Keep pets and children clear of the area while we work
- Try not to wet indoor joints just before the visit
- Mention if the joints have been sealed before
Get a quote
Getting a quote is simple: let us know what needs doing and where. A few photos by email make the job easier to understand, and we’ll come back to you with a quote.
Read more
Quotes for new build mastic in Netherne on-the-Hill
The price is agreed before any work begins. It’s based on:
- The size of the job
- How easy the joints are to reach
- The product the joint needs
- When we can work, for business premises
Homes and businesses are quoted the same way: how much there is to do, how we reach it and what it needs, along with when we can work on site. Ask us for a quote and we’ll go through it with you.
What to tell us for a quote
Photos by email are helpful but not essential. Try to tell us:
- Whether it’s a home or a business
- The rough size of the job
- A few pictures by email, if you can
- Access, such as stairs, a lift or height
We don’t publish a price list. Instead, we send you a clear quote for your job. To arrange one, call 0345 464 0079 or send us an email.
FAQs for Netherne on-the-Hill
Is parking an issue for new build mastic in Netherne on-the-Hill?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Do you work for landlords with property near Coulsdon South station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we will give you a clear price.
How long does the job take?
That depends on how much there is to do, but most jobs take a few hours in a single home. We’ll give you a better idea when we quote.
Where are you based?
We work from Crawley. Our applicators cover Netherne on-the-Hill, along with the rest of our area.
Is it worth resealing while the house is still settling?
Any seal that’s leaking should be redone right away. Cosmetic gaps can wait until the first year or two of movement has passed.
Will it make a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
How much does new build mastic cost in Netherne on-the-Hill?
It depends on the job, so we quote each one individually. For a quick quote, ring 0345 464 0079 or email us and let us know what needs doing and where.
Do you take out the old sealant first?
Yes, always, and completely. New silicone does not stick to old silicone, so the joint is cleaned back first.