Greater London · England
Remedial Sealant in North Finchley
Remedial sealant for North Finchley, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- A shower that leaks however often it’s resealed
- A second bead peeling off the first
- Gaps opening along the back of the worktop
Aftercare tips
Once the sealant has cured, a few habits help it last:
- Don’t wait for a small gap to become a leak
- Run the fan after every shower
- Keep movement joints clear of mortar and paint
- Always have old sealant cut out, not covered
Do not let anyone seal over it later. Over-sealing is how many remedial jobs start.
Warning signs: sealant lifting at the ends, a second bead visible on top of the first, black mould under the silicone, or stains below a bathroom. Each one is worth getting looked at.
Remedial sealant in North Finchley, done properly
In North Finchley, as anywhere, remedial jobs tend to look alike: sealant over sealant, mould under the bead, leaks that come back and movement joints that have split. Each is stripped back and done again properly. We work on shrunken worktop sealant, failed movement joints and mouldy bath & shower sealant, and common reasons people get in touch are leaks that keep coming back after resealing and caulk or the wrong sealant used in a wet area.
In much of London, period terraces have been converted into flats over the years, with bathrooms fitted into whatever space was available. Small, steamy rooms are where mould gets into sealant and grout fastest, and homes in North Finchley are no different.
You are covered for a year from the day we finish. If there’s a problem with it, please phone 0345 464 0079 or email us.
- Location
- North Finchley (N12, N20, N11)
- Region
- Greater London
- Cover
- One year on every job
- Quote
- A clear price before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Places near North Finchley
Also in North Finchley
Why it’s worth doing now in North Finchley
It’s easy to scratch acrylic, enamel or an uPVC frame cutting out old sealant, and any film left behind stops new sealant sticking. Careful removal is most of a remedial job. 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. Dealing with it early is far simpler for homes in North Finchley.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we will go through it with you.
Why choose Mr Mastic in North Finchley
- 180+ five-star Google reviews
- We leave the area clean and tidy
- An ARBOMaster approved applicator
- You choose the colour before work begins
Take a look at what affects the cost and what customers say.
North Finchley questions
I let a flat near New Southgate station. Can you help?
Yes. We work for landlords and agents as well as homeowners, and several properties can go on one quote. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear quote.
Can worn sealant in a flat in North Finchley cause a leak downstairs?
Yes, it can. Water that gets past failed sealant or cracked grout can run under the bath or tray and show up on the ceiling below. Replacing the sealant and grout before that happens is much less trouble than repairing a neighbour’s ceiling.
Where are you based?
We work from Crawley. We cover North Finchley and the rest of Greater London.
My shower still leaks after a reseal. Can you sort it?
Yes. We check it’s the sealant and not the tray, valve or waste, then the joints are stripped and resealed.
How long should I leave it?
It depends on the product and the conditions. Before we leave, we’ll tell you the cure time.
Is there any odour?
Some sealants have a smell while they cure. Ventilation helps.
Can you strip sealant from an acrylic tray safely?
Yes. We cut and lift the old sealant with tools suited to the surface, and the residue is cleaned away. We point out any damage that’s already there.
What should I tell you?
A short description and the location. We’ll ask anything else we need to know.
What happens on the day
We bring everything the job needs with us, so there’s nothing for you to buy. After a quick look at the joints together, we protect the area and start. It normally takes a few hours, depending on how many layers have to come out. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- Surrounding tiles, trays and frames are protected first.
- Every layer of failed sealant is stripped out.
- The joint is degreased and checked for movement and leaks.
- Once dry, a suitable sealant is applied and tooled.
- You get the cure time and our view on why the joint failed.
Before we arrive
- For indoor joints, keep the area dry beforehand if you can
- Tell us about access, such as stairs, a lift or high-level joints
- Let us know about earlier repairs to the joints
Getting a quote
Getting a quote is simple: let us know the job and the location and its rough size. Photos by email help us understand the job.
Related advice
What remedial sealant looks like in North Finchley
London’s water is hard, so limescale builds up on sealant, grout and fittings, and it has to be cleaned off before new sealant goes in. In a London flat, water from a failed bath or shower seal can reach the neighbours below, which is why it’s worth fixing early.
Schools such as Sacks Morasha Jewish Primary School are buildings too, and we reseal washrooms and kitchens in schools and businesses as well as homes. Letting a property close to New Southgate station? Then failed or mouldy sealant is worth putting right between tenancies, before it turns into a leak. Homes close to St. Barnabas Church include some older properties, and walls and floors in older homes can move, and sealant and grout show it first.
North Finchley is about 1 mile north of Finchley, in Greater London. Anywhere in N12, our applicators can take on remedial sealant. 764 places in Greater London are on our list. There’s also a page for London, about 9 miles away.
Postcode districts we cover here for remedial sealant: N12, N20 and N11. If you need remedial sealant at a property on High Road, Lodge Lane and Percy Road or a nearby road, our applicators can take on the job. Main roads around North Finchley include the A1000. We also cover the places around North Finchley: Woodside Park (1 mile west), Oakleigh Park (1 mile north), Whetstone (1 mile north), Friern Barnet (1 mile east) and Finchley (1 mile south). We also work in nearby towns such as London (9 miles south-east), City of Westminster (7 miles south), Marylebone (7 miles south), Kensington (8 miles south), St Pancras (7 miles south) and Shoreditch (8 miles south-east).
Near you in North Finchley
Typical jobs here are in homes near Friary Park, Woodhouse College and The Bohemia pub, among other places. Nearby too are Francis Skaryna Belarusian Library and Museum (0.5 miles west) and St Michael's Catholic Grammar School (under half a mile south-west). For rail, the closest station is New Southgate station, roughly 1.4 miles east. Nearby you’ll also find Finchley Memorial Hospital (0.8 miles south) and Francis Skaryna Belarusian Library and Museum (0.5 miles west). Open spaces near North Finchley include Darland's Lake and Glebelands Local Nature Reserve.
Work for landlords, hotels 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, and it’s easy to sort out between tenants. We can quote for more than one property at once.
What affects the cost of remedial sealant
There’s no set price list, because no two jobs are the same. The quote depends on:
- When we can work, for business premises
- The type of sealant required
- The size of the job
- Mould in or behind the old joints
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or email us and we’ll talk you through it.
Helping us quote
You don’t need to know the technical terms. It helps if you can tell us:
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
- How we’d reach the joints
- Whether it has been sealed before
For remedial sealant in North Finchley, ring 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
DIY sealant or a professional job?
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it does not work out, we can still put it right.
What we can’t put right
In fairness, there are a few things sealant will not fix:
- Cracks in the fitting rather than the joint
- Tiles that have come away from the wall
- Sealant in an older building that needs testing for asbestos first
Not sure which it is? You can ring 0345 464 0079 or email us and we will tell you honestly before booking.
Where we work in North Finchley
- Botched or over-sealed joints
- Mouldy bath & shower sealant
- Shrunken worktop sealant
- Leaking tray & enclosure joints
- Failed movement joints
- Expansion joints