Greater London · England
New Build Mastic in Southwark
Plot mastic for developers and snagging failed sealant in new homes for Southwark, backed by a one-year guarantee. Call for a quick quote.
- Worktop and upstand sealant coming away
- Gaps opening as the house dries out and settles
- Shower seals failing in the first year or two
New build mastic for homes and businesses in Southwark
Snagging sealant properly means taking the failed bead out completely. New silicone won’t bond to old silicone, so the joint is cut out, cleaned, dried and resealed. We work on bathrooms & en suites, windows & doors and skirting & floors, and common reasons people get in touch are internal frame sealant that has split and sealant that never bonded to the surface.
Across London, commercial floors have movement joints that break down under heavy foot traffic, while new homes need a neat, sound finish around frames, baths and kitchens before handover, in Southwark and beyond.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- Southwark (SE1, SE11)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
The process
On the day, we look over the joints with you first. We protect the surfaces around the joints before any work starts. The work usually takes a few hours for most snagging lists, longer for a run of plots. For a job in Southwark, parking and access are the things to plan: let us know about parking, the floor we will be working on and any lift or shared entrance.
- 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 down to clean surfaces.
- We clean out the dust and grit left from the build.
- We prime where needed and apply a sealant suited to each joint.
- We tool every joint neatly and tell you when each area can be used.
Getting ready for the visit
- Mention any leaks or damp you’ve noticed
- For business premises, tell us about site rules or sign-in
- Let us know about parking restrictions
Getting a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Related advice
What affects the quote in Southwark
The price is agreed before any work begins. It takes into account:
- How much there is to do
- Whether there’s mould to deal with
- Whether old sealant or filler has to be cut out
- The number of rooms or windows
Combining jobs into one visit is usually more efficient than separate visits. We will send you a clear quote for the lot.
What we need to know
Photos help, but a description is a good start. Try to tell us:
- The problem you’ve noticed
- The address or postcode of the job
- Pictures of the joints, sent by email
- Whether it’s a home or a business
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we’ll explain what’s involved before giving you a price.
What happens if it’s left?
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. 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. Putting it right early is much less trouble.
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote.
Why us?
- Arbo and Everbuild products
- Full insurance on every job
- Sealant colour chosen to suit
- Neat joints and a tidy finish
Common questions in Southwark
Is Southwark in your area for new build mastic?
Yes, Southwark is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or send us an email and tell us what needs doing.
Is parking an issue for new build mastic in Southwark?
Parking in Southwark, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
What sealant do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We explain the product when we quote.
Can I add another job to the visit?
Yes, we can. More than one area can go on one quote.
Will the old sealant be removed?
Always. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Where are you based?
We work from Crawley. Our applicators cover Southwark.
How long should I leave it?
That depends on the sealant used, so follow the cure time we give you.
Do you work for hotels and businesses?
Yes. We can plan bigger jobs in stages.
For landlords and businesses
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
Mouldy or split sealant often shows up at the end of a tenancy. Several properties can be quoted together.
What sealant work can’t fix
It helps to know what we can’t do too:
- Cracked trays, tiles or worktops
- Settlement cracks that need a surveyor
- A tray or bath that is not properly supported, until it’s fixed
If you are not sure, just call 0345 464 0079 or send us an email and we’ll give you a straight answer.
Where we work in Southwark
- Show homes
- Skirting & floors
- Plot handovers
- Kitchens
- Bathrooms & en suites
- Windows & doors
Joints and finishes in Southwark homes
Many of London’s new homes are flats in bigger 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, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
As a London address, Southwark can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. For new homes near Elephant & Castle station, it’s worth checking the sealant early, while snags are still fresh.
Southwark is about 0 miles north-west of London, in Greater London. If you need new build mastic in Southwark, please phone 0345 464 0079 or send us an email for a quick quote. We cover Greater London from our Crawley base. Across Greater London, we cover 764 places, and Southwark is one of them.
All of SE1 and SE11 is within our area for new build mastic. Local streets include Borough Square, Trinity Church Square and Merrick Square, and we cover them all. Main roads around Southwark include the A300 and B240, so getting to you is simple. Neighbouring places we cover for new build mastic include Tower Hill (1 mile north-east), City of London (1 mile north), Aldgate (1 mile north-east), Bishopsgate (1 mile north-east) and Barbican Estate (1 mile north). Further out, we also cover City of Westminster (3 miles west), Kensington (5 miles west), Walthamstow (7 miles north-east), Hampstead (5 miles north-west), Ruislip (14 miles west) and Brompton (3 miles west).
Landmarks near Southwark
Around Southwark, our work takes us to homes and buildings near London School of Musical Theatre, Little Dorrit's Playground and St Mary-at-Hill and the streets around them. Nearby too are Ark Globe Academy (less than half a mile south-east), The BFI Reuben Library (0.9 miles north-west) and The Gladstone Arms (less than half a mile north-east). The nearest railway station is Elephant & Castle station, roughly 0.5 miles south. Well-known places in the area include Gabriel's Wharf (0.7 miles north-west) and Baynard's Castle (0.8 miles north). Not far away are Ludgate Hill and Bellenden Road Nature Garden.
Places near Southwark
Also in Southwark
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Different surfaces, different methods
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.
Kitchens
Worktop, upstand and sink joints in new kitchens often get a hurried bead. We remove it and reseal with a kitchen-suitable sealant.