Greater London · England
New-build mastic & snagging in Westerham, Greater London
Specialist new build mastic for Westerham: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Worktop and upstand sealant coming away
- Second-fix sealing on new plots
- Frame joints opening as the plaster dries
New build mastic in Westerham
A new house keeps drying out and settling for its first couple of years. Timber dries and shrinks, and baths and trays settle, so sealant that was laid quickly before handover often cracks. We work on bathrooms & en suites, plot handovers and kitchens, and common reasons people get in touch are messy sealant that spoils new finishes and cracks appearing as a new home settles.
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.
A 12-month guarantee comes as standard.
- Location
- Westerham (TN16)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
New build mastic around Westerham
Much of London’s new housing is flats in larger developments, where snags may need reporting through the developer or the managing agent. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
As a London address, Westerham can be tricky for parking: let us know about parking bays, permits or a driveway. For new homes near Hurst Green station, it’s worth checking the sealant early, while snags are still fresh.
Westerham is about 5 miles west of Sevenoaks, in Greater London. Wherever you are in the TN16 postcode area, we can carry out new build mastic at your property. Westerham is one of 764 places in Greater London we cover. Our Crawley page covers work nearby, about 16 miles away.
All of TN16 is covered for new build mastic. Streets in the area include Market Square, London Road and High Street, all of which we cover. You’ll find Westerham on the A25 and B2024, so it’s easy for us to get to with everything needed for new build mastic. Neighbouring places we cover for new build mastic include Force Green (1 mile north), Moorhouse Bank (1 mile south-west), Goodley Stock (2 miles south), The Chart (2 miles south-west) and South Street (2 miles north-west). Within a short drive, we also cover Orpington (8 miles north), New Cross (15 miles north), Thornton Heath (12 miles north-west), Croydon (10 miles north-west), East Dulwich (15 miles north-west) and Plumstead (15 miles north).
Landmarks near Westerham
Around Westerham, our work takes us to homes and buildings near The Olde House At Home Public House and the streets around them. For rail, the closest station is Hurst Green station, about 3.4 miles south-west of the centre. Well-known places in the area include Tandridge Priory (2.2 miles south-west). Open spaces near Westerham include Betsom's Hill and Dryhill Nature Reserve.
Should I try it myself first?
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
Landlords, agents and businesses in Westerham
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we will quote.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a 12-month guarantee.
What the job involves on each surface
Windows and doors
The gap between a new frame and its plaster reveal often opens up. We remove cracked sealant and apply a flexible one that suits the frame.
Skirting and floors
Where the floor meets a bath panel or kitchen plinth, the joint keeps mop water out. They get a flexible, water-resistant sealant.
Why act early in Westerham
A tube of sealant from the DIY shop will not fix the cause: grit, unprimed surfaces and old layers underneath. Cutting out, cleaning and priming are what make the difference. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Westerham, the repair is bigger than the sealant job would have been.
Combining jobs into one visit is generally more efficient than separate visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
Why us?
- Any old sealant cut out fully, not covered over
- Colour picked to suit the job
- We agree the colour with you first
- Homes, businesses and hotels
Read our cost guide and what customers say.
Places near Westerham
More services for Westerham
When something else is needed
We’d rather tell you now than do work that won’t last, so here’s what sealant can’t put right:
- Baths and trays that move too much for sealant to cope with
- Cracked trays, tiles or worktops
- Settlement cracks that need a surveyor
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly before you book.
Where we work in Westerham
- Bathrooms & en suites
- Plot handovers
- Kitchens
- Windows & doors
- Skirting & floors
- Show homes
What affects the quote in Westerham
Call for a quick quote. The main things that affect it are:
- The amount of work
- Any working-time requirements on site
- Whether the work is at height
- Which sealant suits the joint
We don’t show prices on the website, because the cost depends so much on the job itself. For a quick quote, please phone 0345 464 0079 or send us an email and we will talk you through it.
Helping us quote
When you contact us, it’s useful to know:
- Where the job is, and your postcode
- A few pictures by email, if you can
- How many joints, rooms or windows are involved
- The type of property
Need a quote? Please ring 0345 464 0079 or email us with a few details. You will know what we plan to do, and what it will cost, before any work begins.
What happens on the day
When we get to you, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take a few hours in a single home. In a London area like Westerham, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- 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, 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.
Before we arrive
- Keep children and pets away from the work area
- Tell us if parking is tricky
- Tell us about access, such as stairs, a lift or high-level joints
How to get a quote
For a quick quote, get us on the phone, or email us if that’s easier. Describe what needs sealing and we will explain what’s involved before giving you a price.
Read more
Common questions in Westerham
Is parking a problem for a job in Westerham?
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 work for landlords with property near Hurst Green station?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can be quoted together. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear price.
Where is Mr Mastic based?
We’re based in Crawley, and we cover South East England, London and all of Scotland.
Are you insured?
Yes. We’re fully insured for domestic and commercial work.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint.
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.
Should I try DIY first?
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 I have to be there?
Access is agreed with you when the job is booked. Indoors, that usually means someone at home.