South East England and London

New Build Mastic in Greater London

Wherever you are in Greater London, our applicators can help with new build mastic. A clear quote before we start, and a one-year guarantee.

Book new build mastic in Greater London

Call 0345 464 0079

Get a quick quote

New build mastic in every part of Greater London

Plot mastic for developers and snagging failed sealant in new homes. Choose your town from the list to see local details, and call or email us for a quick quote.

Main towns

How new build mastic works in Greater London

If your new home has a leaking shower seal, open skirting joints or untidy sealant, we can help. While the builder’s snagging or warranty period runs, report it to them first. Typical jobs include skirting joints opening in the first winter and shower seals failing in the first year or two, across skirting & floors, show homes and plot handovers.

When we get to you, we check the joints match what you told us. If anything is different, we explain it before carrying on. After that, the work takes a few hours for most snagging lists, longer for a run of plots.

First, the list of joints is agreed from your snagging sheet or plot schedule.
The failed sealant is removed completely.
Joints are vacuumed and cleaned of building dust.
Primer goes on where the surface and product need it, then the new sealant.
Each bead is tooled and the cure times explained.

What you will pay

Leaving a failed joint usually makes the job bigger, not smaller. If you’re unsure, phone 0345 464 0079 or send us an email and we will give you an honest view and a quote.

Why choose Mr Mastic

180+ five-star Google reviews
Trusted Arbo and Everbuild sealants
We leave the area clean and tidy
A choice of colours where the product allows

How to get a quote

Want a quote for new build mastic? Please call 0345 464 0079 or drop us an email and tell us about the job. We will explain what we’d do and send you a clear quote before we start.

What’s near London

Locally, jobs take us to homes and businesses close to St Mary-at-Hill, St George the Martyr and The BFI Reuben Library and the streets around them. Also close by are Trinity Arms Public House (within half a mile south-east), Ark Globe Academy (less than half a mile south), Charles Dickens Primary School (within half a mile north-west) and Newington Gardens (under half a mile south). There’s a railway station in London itself: Elephant & Castle station. Nearby you’ll also find Surrey Dispensary (under half a mile south-east) and Baynard's Castle (0.9 miles north). Green spaces nearby include Bellenden Road Nature Garden and St. James's Park Lake.

Nearby schools include London School of Musical Theatre (less than half a mile west)

New build mastic across Greater London: local notes

From London, City of Westminster and Marylebone to its smaller places, Greater London has new developments as well as older homes. Snagging in new homes and floor joints in older ones are both part of the work.

London and the South East are among the drier parts of the UK, though outside sealant still needs a dry, clean joint, so work across Greater London is planned around the weather.

London: For new homes near Elephant & Castle station, it’s worth checking the sealant early, while snags are still fresh. In and around London, as anywhere, good new build mastic starts with a clean, dry, properly prepared joint.

Should I try it myself first?

Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.

If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.

What we are called out for in Greater London

Later trades and the final clean can damage fresh sealant. A bead disturbed before it has cured may never seal properly.

Look out for these signs:

Second-fix sealing on new plots
Sealant applied over dusty or wet surfaces
Joints pulling apart as timber shrinks
Smeared, uneven beads picked up at snagging

For landlords and businesses

Hotels need rooms back in use, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.

We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.

What affects the quote in Greater London

We quote each job individually. These are the things that affect it:

Whether the work is at height
When we can work, for business premises
Any mould that needs treating
The type of sealant required

Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.

What to tell us for a quote

The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:

Where the property is
The type of property
Any previous sealing or DIY work
Pictures of the joints, sent by email

We do not publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To arrange one, phone 0345 464 0079 or send us an email.

How to look after the new joints

Once the sealant has cured, a few habits help it last:

Ventilate bathrooms well, especially in the first year
Clean sealant with mild detergent, not abrasives
Put sealant faults on your snagging list early
Do not seal over failed sealant yourself

Follow the cure time we give you before the area gets wet. Most silicones need around a day to cure enough for use.

A seal that splits early is often a sign of movement. Getting it resealed properly, and any movement checked, stops it recurring.

FAQs for Greater London

Can landlords and businesses book you?

Yes, we do. Domestic, commercial and hotel work are all part of what we do, and we’re fully insured.

Will you leave a mess?

Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.

How do I get a quote for new build mastic in Greater London?

We don’t publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. You’ll get a clear quote before any work starts.

Will there be a smell?

There can be a smell while the sealant cures, but it fades. Opening a window helps.

Why does sealant fail so quickly in new builds?

It’s common, and there are normally two reasons: movement as the house dries and settles, and sealant laid onto dust without primer. Cutting it out and resealing properly fixes both.

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.

Can you reseal over the builder’s sealant?

No. Fresh silicone doesn’t stick to the old layer, so sealing over the top fails quickly. We cut the old bead out completely.