Greater London · England
New Build Mastic in Hornsey
Problem with your new-build sealant joints in Hornsey? We cut out the old, prepare the joints and apply the right sealant, with a 12-month guarantee.
- Leaking shower tray seals in a new home
- Worktop and upstand sealant coming away
- Untidy sealant flagged on a snagging list
About our new build mastic in Hornsey
Some owners wait for the first year’s movement before having joints redone. That makes sense for small gaps that are just cosmetic, but a seal that is letting water through needs doing now. We work on windows & doors, plot handovers and kitchens, and common reasons people get in touch are sealant applied over dusty or wet surfaces and plot mastic for developers ahead of handover.
Across London, commercial floors have movement joints that break down under heavy foot traffic, and new homes need their plot mastic finished properly before handover, in Hornsey and beyond.
All of our work is guaranteed for twelve months, and the guarantee is the same wherever you are.
- Place
- Hornsey (N8, N22)
- Wider area
- Greater London
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Why deal with it now?
Sealant done properly at handover means fewer callbacks. Every return visit for a failed seal takes time, and they’re avoidable with good preparation. In a flat in Hornsey, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.
Why us?
- Domestic, commercial and hotel work
- A sealant colour to suit the surroundings
- We leave the area clean and tidy
- Every job guaranteed for a year
See our cost guide and customer reviews.
Different surfaces, different methods
Bathrooms and en suites
En suite showers are a common source of leaks into the room below. Resealing properly keeps water where it belongs.
Show homes
Show homes need sealant that looks right from day one. We lay neat, even beads in colours to suit the finishes.
Joints and finishes in Hornsey homes
Many of London’s new homes are flats in bigger developments, where snagging may go through the developer or 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, Hornsey can be tricky for parking: let us know about parking bays, permits or a driveway.
Hornsey is about 3 miles east of Finchley, in Greater London. Hornsey gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Across Greater London, we cover 764 places, Hornsey among them. You can also see our page for London, roughly 6 miles from Hornsey.
Our applicators cover all of the N8 and N22 postcode area for new build mastic and the streets around it. You will find streets such as High Street, Brandon Place and Cross Lane, all of which we cover. We also cover Turnpike Lane (1 mile east), Crouch End (1 mile south-west), Stroud Green (1 mile south-east), Wood Green (1 mile north-east) and Noel Park (1 mile north-east). Larger places within reach include London (6 miles south), City of Westminster (5 miles south), Marylebone (5 miles south), Kensington (7 miles south-west), St Pancras (4 miles south) and Shoreditch (5 miles south).
Local landmarks in Hornsey
Locally, jobs take us to homes and businesses close to Great Northern Railway pub, Priory Park and Greek Secondary School of London and the streets around them. Hornsey has its own railway station: Hornsey station. Nearby you’ll also find Hornsey Central Hospital (0.7 miles west) and Broomfield House Museum (2 miles north). Open spaces near Hornsey include Darland's Lake and Highgate Hill.
More services for Hornsey
Common questions in Hornsey
Is Hornsey in your area for new build mastic?
Yes, Hornsey is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear price.
I let a flat near Hornsey station. Can you help?
Yes. We work for landlords and agents as well as householders, and several properties can be quoted together. You can ring 0345 464 0079 or drop us an email with the details for a clear quote.
Is it messy?
We keep the work tidy. We protect what’s around the joints.
Do the sealants smell?
Possibly a little. Any smell clears as the sealant cures, and ventilation helps.
Who should fix failed sealant in a new build?
Start with your builder while their snagging or warranty period runs. After that, or if their repair keeps failing, we can do it.
Where is Mr Mastic based?
Mr Mastic is based in Crawley. Our applicators cover Hornsey.
Is the work guaranteed?
Yes. Every job comes with a 12-month guarantee.
What should I tell you?
A short description and the location. We’ll ask anything else we need to know.
What sealant work cannot fix
Some problems need a builder, plumber or other trade rather than us:
- Broken tiles or a split tray
- Settlement cracks that need a surveyor
- Your warranty claim itself, which is between you and the builder
Not sure which it is? You can call 0345 464 0079 or email us and we will tell you honestly.
Joints and surfaces we work on
- Kitchens
- Skirting & floors
- Plot handovers
- Windows & doors
- Bathrooms & en suites
- Show homes
When to call us in Hornsey
Sealant is often one of the last jobs before handover. Dusty, unprimed joints are common, and the sealant sits on grit instead of the surface.
It’s worth asking for a quote if you see:
- Smeared, uneven beads picked up at snagging
- Skirting joints opening in the first winter
- Frame joints opening as the plaster dries
- Gaps opening as the house dries out and settles
If you’ve bought a new home near Hornsey station, the sealant around baths, showers and frames is worth checking in the first year or two.
What to look for in a quote
- Whether the sealant suits the joint
- What insurance they hold
- How hidden problems are handled
- How the surfaces are prepared before sealing
What happens on the day
We bring everything the job needs with us. After a quick look at the joints together, we protect the area and start. It normally takes anything from a few hours to several days, depending on the number of plots. In Hornsey, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We look at why each joint failed, including any movement.
- Old sealant is cut out and the joints cleaned.
- 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.
- The finished joints are checked and the cure times given.
Before we arrive
- Let us know about stairs, lifts or work at height
- Clear the area around the work
- Keep children and pets away from the work area
How to get a quote
Every job is quoted individually, so the first step is telling us about yours. Simply phone 0345 464 0079 or email us and describe the job.
Related advice
Quotes for new build mastic in Hornsey
Every job gets its own quote. These are the things that affect it:
- Whether there’s mould to deal with
- How easy the joints are to reach
- The type of sealant required
- The number and length of the joints
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote.
What we need to know
Photos by email are helpful but not essential. Please mention:
- Where the job is, and your postcode
- Whether it’s a home or a business
- Photos by email, if that’s easy
- How we’d reach the joints
If you’re in Hornsey and need new build mastic, phone 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you will get a clear quote before we start.
Keeping the joints in good condition
Simple care keeps the joints in good condition. Our advice:
- Do not wait for the house to settle if water is getting through
- Put sealant faults on your snagging list early
- Photograph failed sealant before it’s redone
- Avoid running a DIY bead over the old one
Do not stand on the bath edge or the lip of the tray in the first few weeks. Report any movement in a bath or tray.
The sooner you deal with untidy or cracking sealant, the less there is to put right. Small faults turn into leaks if left.