Greater London · England
New Build Mastic in Nunhead
New build mastic for Nunhead, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Sealant that never bonded to the surface
- Frame joints opening as the plaster dries
- Joints pulling apart as timber shrinks
Leave it or put it right?
Water getting past a failed seal in a new build reaches walls and floors that are still settling. Resealing promptly protects the new finishes around it. In a flat in Nunhead, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please ring 0345 464 0079 or drop us an email.
Why us?
- A choice of colours where the product allows
- We leave the area clean and tidy
- Domestic, commercial and hotel work
- 20+ years of sealant experience
See what affects the cost or our reviews.
New build mastic in Nunhead, done properly
Across Nunhead, we work for both new-home owners and the builders handing those homes over. Whether it’s one en suite or a run of plots, the method is the same: cut out, clean, prime where needed and reseal neatly. We work on skirting & floors, windows & doors and show homes, and the jobs we see most are smeared, uneven beads picked up at snagging and new-build shower sealant that has already split.
Much of London’s new housing is flats in larger developments. In a new development, snags are often reported through the developer or the managing agent, and shower seals that fail early, skirting joints that open up and gaps at thresholds are all common snags.
The work is guaranteed for twelve months. If something isn’t right with it in that time, tell us and we will put it right.
- Location
- Nunhead (SE15, SE4, SE14)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Can I do it myself?
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
The difference is mostly in the preparation and the 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.
How it works
There’s no need to move everything out, just the space around the work. Everything nearby is protected, and the work takes a few hours for most snagging lists, longer for a run of plots for a typical job. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Nunhead. 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.
- The failed sealant is removed completely, with no layer left behind.
- We clean out the dust and grit left from the build.
- We prime where needed and apply a sealant suited to each joint.
- Each bead is tooled and the cure times explained.
Preparing for the visit
- Try not to wet indoor joints just before the visit
- On commercial sites, let us know about site rules
- Keep children and pets away from the work area
Ask for a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. Whenever you are ready, ring 0345 464 0079 or send us an email.
Related advice
Surface by surface
Skirting and floors
Floors and skirting move as the house dries and the heating runs. Caulk cracks; a flexible sealant moves with it in a colour to suit.
Kitchens
Worktops in new homes can move slightly as the house dries, which opens gaps along the back. We reseal them with a flexible sealant.
Honest limits
To be straight with you, some problems need a different trade:
- Damaged fittings that need replacing
- Disputes or warranty claims with your builder
- Leaks from pipes, valves or wastes, which need a plumber
If you are not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer.
What we seal
- Windows & doors
- Bathrooms & en suites
- Plot handovers
- Kitchens
- Skirting & floors
- Show homes
For landlords and businesses
Failed sealant is one of the commonest items on a check-out report. We can quote for more than one property at once.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
Nearby places to Nunhead
What else we do in Nunhead
Aftercare tips
Once the sealant has cured, a few habits help it last:
- Check bath and shower seals every few months as the house settles
- Clean sealant with mild detergent, not abrasives
- Act quickly if a seal starts to leak
- Ventilate bathrooms well, especially in the first year
Keep an eye on the joints over the first couple of years. Hairline gaps can open as timber and plaster dry 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.
Joints and finishes in Nunhead homes
London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Much of London’s new housing is flats in larger developments, where snagging may go through the developer or managing agent.
For new homes near Nunhead station, it’s worth checking the sealant early, while snags are still fresh. As a London address, Nunhead can be tricky for parking: let us know about parking bays, permits or a driveway.
Nunhead is about 1 mile south-west of New Cross, in Greater London. Whether you’re in the middle of Nunhead or further out, we cover new build mastic for every kind of property. Our Greater London coverage runs to 764 places, and Nunhead is one of them.
All of SE15, SE4 and SE14 is covered for new build mastic, from the main roads to the quietest streets. That includes homes and businesses on Rye Road, Nash Road and Kitto Road and the roads around them. Close by, we work in Telegraph Hill (1 mile north-east), Honor Oak (1 mile south), Peckham (1 mile north-west), New Cross (1 mile north-east) and Brockley (1 mile south-east). Larger places within reach include London (3 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (7 miles west), St Pancras (5 miles north-west) and Shoreditch (5 miles north).
Near you in Nunhead
We work in homes and buildings around The Ivy House, Peckham Rye and Allenby Tutorial Trust, among other places. There’s a railway station in Nunhead itself: Nunhead station. Nearby you will also find Greenwich Castle (2.4 miles north-east) and Lewisham Shopping Centre (1.7 miles east). Open spaces near Nunhead include Knight's Hill and One Tree Hill.
Nunhead questions
Is parking an issue for new build mastic in Nunhead?
Parking in Nunhead, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
I let a flat near Nunhead station. Can you help?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Can new sealant go on top of the old bead?
No. The old sealant is cut out fully, the joint cleaned and primed where needed, before resealing.
What should I tell you?
Let us know what needs doing and where, with photos by email if possible. We’ll ask anything else we need to know.
When is the best time to reseal in a new build?
Any seal that’s leaking should be redone right away. For small cosmetic gaps, waiting until the house has settled can save doing them twice.
Do you do commercial work?
Yes. We work in offices, washrooms, hotels and other commercial premises. Working times can be discussed when we quote.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
Why has my new-build shower seal failed already?
It’s common, and there are generally two reasons: the house moving as it dries, and sealant that never bonded properly. A proper reseal deals with both.