Greater London · England
Selsdon New Build Mastic
Plot mastic for developers and snagging failed sealant in new homes for homes and businesses in Selsdon and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Frame joints opening as the plaster dries
- Second-fix sealing on new plots
- Cracked caulk along new skirting
New build mastic for homes and businesses in Selsdon
For builders and developers, we work through plots to the schedule you give us. We seal bathrooms, kitchens, windows, doors and skirting so plots are ready to hand over using the right product for each joint. We work on skirting & floors, plot handovers and bathrooms & en suites, and people most often call us about sealant that never bonded to the surface and plot mastic for developers ahead of handover. Some people call us the mastic man, others the silicone man or the sealant specialist; in Selsdon, the job is the same: proper preparation and the right sealant for every joint.
New flats are going up across London, many of them in larger developments. Snagging there often goes through the developer or managing agent, and shower seals that fail early, skirting joints that open up and gaps at thresholds are all common snags.
The work is covered for a year after we finish. If anything is not right with it, phone 07833 053749 or drop us an email.
- Place
- Selsdon (CR2, CR0)
- Wider area
- Greater London
- Cover
- One year on every job
- Quote
- A clear price before work begins
- Telephone
- 07833 053749
- Page updated
- 26 October 2026
Common questions in Selsdon
Do you work for landlords with property near Sanderstead station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can call 07833 053749 or drop us an email with the details for a clear quote.
Is parking a problem for a job in Selsdon?
Parking in Selsdon, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
Do you work for developers?
Yes. We seal plots to the developer’s programme, room by room. Tell us the plots and the joints involved and we will quote.
Should I wait before resealing?
If the seal has failed and water is getting in, do it now. Small gaps that are just cosmetic can be resealed once movement has slowed.
My new home is still under warranty. Should I contact you?
Start with the builder if you are in the snagging or warranty period. Once that’s done, or if they will not put it right, we can reseal it properly.
What colour sealant will you use?
It depends on the joint: white or clear for most sanitary joints, colours for worktops, floors and frames. We’ll agree it with you first.
Do you work through snagging lists?
Yes. Send the list and a few pictures of the sealant items, and we will quote. We’ll flag anything that needs another trade.
What should I tell you?
Let us know what needs doing and where, plus pictures if you have them. We’ll ask anything else we need to know.
What the job involves on each surface
Skirting and floors
Wet-area floor joints need a flexible seal. They get a flexible, water-resistant sealant.
Bathrooms and en suites
New-build bathrooms and en suites are where sealant fails most often. The old sealant comes out and anti-fungal sanitary silicone goes in after cleaning and priming.
Common problems we fix in Selsdon
New homes are full of moisture from plaster, screed and concrete, and it dries out over the first couple of years. As it does, timber shrinks and joints open and the sealant has to cope with the movement.
Signs it’s time to call us include:
- Smeared, uneven beads picked up at snagging
- Shower seals failing in the first year or two
- Plot mastic for developers ahead of handover
- Beads laid onto grit and dust from the build
As a London address, Selsdon can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Before you book anyone
- What happens if the job turns out different
- What guarantee comes with the work
- How much experience the applicator has
- What insurance they hold
When it is not the sealant
We’d rather tell you now than do work that will not last, so here’s what sealant can’t put right:
- Settlement cracks that need a surveyor
- Plumbing faults behind the sealant
- Damaged fittings that need replacing
If you are not sure, just ring 07833 053749 or email us and we’ll give you a straight answer before you book.
Surfaces we seal
- Bathrooms & en suites
- Plot handovers
- Kitchens
- Show homes
- Windows & doors
- Skirting & floors
New homes and floors in Selsdon
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. Many of London’s new homes are flats in bigger developments, where snags may need reporting through the developer or the managing agent.
For new homes near Sanderstead station, it’s worth checking the sealant early, while snags are still fresh.
Selsdon is about 2 miles south-east of Croydon, in Greater London. Every kind of property in Selsdon can book us for new build mastic, old or new, large or small. The work is guaranteed for a year. Our Greater London coverage runs to 786 places, and Selsdon is one of them.
We work across the CR2 and CR0 postcode area for new build mastic and the streets around it. New build mastic is available to properties on York Road, Byron Road and Abbey Road and the roads around them. Other places close to Selsdon include Forestdale (1 mile east), Addington (1 mile north-east), Sanderstead (1 mile south-west), Coombe (1 mile north-west) and Farleigh (2 miles south-east). Larger places within reach include London (11 miles north), City of Westminster (12 miles north), Marylebone (13 miles north), Kensington (12 miles north-west), St Pancras (13 miles north) and Shoreditch (13 miles north).
Landmarks near Selsdon
We work in homes and buildings around Royal Russell School, The Sir Julian Huxley pub and The Quest Academy and the streets around them. The closest station to Selsdon is Sanderstead station, about 1.7 miles west. Other landmarks nearby include St George's Walk (2.7 miles north-west) and Croydon Airport Visitor Centre (2.9 miles west). Not far away are Duppas Hill and Bramley Bank.
How it works
When we get to you, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. Most jobs then take 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 start by going through the snagging items or plot schedule with you.
- Every bit of the old builder’s sealant is cut out, with no layer left behind.
- Joints are vacuumed and cleaned of building dust.
- 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.
Preparing for the visit
- Mention if the joints have been sealed before
- Let us know if you’ve seen damp or leaks
- Mention any tricky access
Get a quote
It all starts with a short chat. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. When it suits you, ring 07833 053749 or drop us an email.
Related advice
DIY sealant or a professional job?
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Looking after it afterwards
So the new joints stay in good condition:
- Wipe joints with warm soapy water
- Photograph failed sealant before it’s redone
- Raise failed sealant with the developer while you are covered
- Ventilate bathrooms well, especially in the first year
Photograph failed sealant before it’s redone and keep the builder’s replies. It’s useful if you need to raise other issues later.
Leave a failed new-build seal and water can reach the floor and the ceiling below. Catching it early keeps the fix to the sealant and protects the rest of the house.
Work for landlords, hotels and businesses
If you manage several properties in or around Selsdon, jobs at different addresses can go on one quote. Just tell us the addresses and what each one needs, and pictures by email help.
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we’ll quote.