Greater London · England
Kenton New Build Mastic
Plot mastic for developers and snagging failed sealant in new homes in Kenton, with a 12-month guarantee on every job. Call for a quick quote.
- Joints pulling apart as timber shrinks
- Shower seals failing in the first year or two
- Sealant applied over dusty or wet surfaces
New build mastic in Kenton
Across Kenton, we work for both new-home owners and the builders handing those homes over. One shower or a whole phase of plots, the method doesn’t change: remove, clean, prime where needed, then a neat new bead. If you are dealing with cracked sealant around new window and door frames and gaps opening as the house dries out and settles, we can put it right.
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.
Big or small, you get the same one-year guarantee in Kenton and across Greater London.
- Place
- Kenton (HA3, HA7, HA1)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
New build mastic in Kenton: local notes
Much of London’s new housing is flats in larger developments, where snagging may go through the developer or managing agent. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
As a London address, Kenton can be tricky for parking: let us know about parking bays, permits or a driveway.
Kenton is about 2 miles south of Stanmore, in Greater London. Whether you’re in the middle of Kenton or further out, we cover new build mastic for every kind of property. We cover 764 towns and villages across Greater London, from the larger towns to small villages. There’s also a page for London, about 11 miles away.
Work in HA3, HA7 and HA1 is quoted and booked the same way as anywhere else. If you need new build mastic at a property on Retreat Close, Kenton Road and Woodgrange Avenue or a nearby road, we can help. Kenton is on the A4006, so it’s easy for us to get to. Neighbouring places we cover for new build mastic include South Kenton (1 mile south), Northwick Park (1 mile south-west), Greenhill (1 mile west), Wealdstone (1 mile north-west) and Harrow on the Hill (2 miles south-west). We also work in nearby towns such as London (11 miles south-east), City of Westminster (8 miles south-east), Marylebone (8 miles south-east), Kensington (7 miles south-east), St Pancras (9 miles south-east) and Shoreditch (11 miles south-east).
Landmarks near Kenton
Locally, jobs take us to homes and businesses close to Uxendon Manor Primary School, The New Moon pub and Preston Park. Kenton’s nearest station is Kenton station, about 0.5 miles south-west. Other landmarks nearby include St. Anns (1.3 miles west) and Hilfield Castle (4.9 miles north). Green spaces nearby include Masons Field and Northala Fields.
Kenton questions
Is parking a problem for a job in Kenton?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Can you do new build mastic in Kenton?
Yes. We work across London and the South East, and Kenton is part of that. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Do you work through snagging lists?
Yes. Snagging lists are a common starting point for us. We agree the sealant items with you before work begins.
I rent my home. Can I book you?
Of course. Check with your landlord; we can send the quote to them too.
Will you just run a new bead over the existing one?
No. Fresh silicone does not stick to the old layer, so sealing over the top fails quickly. The old sealant always comes out first.
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 do plot mastic on a new development?
Yes. We take on second-fix sealant work across new plots. We clean and prime joints properly to keep callbacks down.
Do you have insurance?
Yes. We’re fully insured, with over 20 years’ experience in sealant work.
Places near Kenton
More services for Kenton
What affects the quote in Kenton
We do not publish a price list. What we look at:
- Whether there’s mould to deal with
- The product the joint needs
- How many rooms, windows or areas are involved
- Whether old sealant or filler has to be cut out
The cost reflects the work involved, not a rough estimate. That is why we ask about the job first and give you a clear price before any work starts.
What to tell us for a quote
To make quoting easier, let us know:
- Roughly how big the job is
- Whether it’s a home or a business
- What the problem is, such as mould, gaps, leaks or cracking
- Where the job is, and your postcode
If you are in Kenton and need new build mastic, ring 0345 464 0079 or send us an email. Tell us what the problem is and where, and you’ll get a clear quote before work begins.
Looking after it afterwards
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Report sealant problems to your builder during the snagging period
- Keep pictures and emails about snagging items
- Watch for new gaps as the house dries out
- Resist patching a failed seal with a tube from the DIY shop
Clean the sealant with a mild detergent and a soft cloth. Keep scourers and harsh chemicals off it as they wear the bead.
Report failed sealant to the builder while you are in the snagging period. After that, putting it right may fall to you, so raise it early.
How it works
Our applicators work methodically: protect, prepare, seal, tidy. For most jobs that takes a few hours for most snagging lists, longer for a run of plots. In Kenton, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- Each joint is checked for movement before we start.
- We remove the failed sealant and clean the joints.
- Joints are dried and primed where the product calls for it.
- New sealant goes in, with baths filled first so they’re at their heaviest.
- We check every joint and leave you with the cure times.
Before we arrive
- Tell us if parking is tricky
- Tell us about any previous sealing or DIY attempts
- Tell us about access, such as stairs, a lift or high-level joints
Ask for a quote
Need a quote? Please call 0345 464 0079 or drop us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Related advice
When to call us in Kenton
Later trades and the final clean can damage fresh sealant. If it’s disturbed before curing, the joint can be left weak.
Signs it’s time to call us include:
- Cracks appearing as a new home settles
- Worktop and upstand sealant coming away
- Internal frame sealant that has split
- Leaking shower tray seals in a new home
For new homes near Kenton station, it’s worth checking the sealant early, while snags are still fresh.
What to look for in a quote
- When the joint can take water or movement
- What product goes in the joint
- What insurance they hold
- What happens if they find a problem under the old sealant
What the job involves on each surface
Windows and doors
External mastic around new windows and doors is sometimes rushed or missed. It’s resealed with an exterior sealant suited to the frame and wall.
Show homes
In a show home, the sealant is on display. Every bead is neat and coloured to suit the room.
DIY versus a professional finish
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
Leave it or put it right?
Sealant done properly at handover means fewer callbacks. Snagging visits for failed sealant cost time on every plot and most come down to preparation. In London conversions, one flat’s bathroom is often above another flat’s ceiling, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Why choose Mr Mastic in Kenton
- Colour picked to suit the job
- A 12-month guarantee on all work
- Old sealant always removed completely
- ARBOMaster approved applicator
Take a look at our cost guide and our reviews.