Greater London · England
Commercial Sealant in Underhill
Sealant work for offices, hotels, washrooms and commercial buildings in Underhill, with a one-year guarantee on every job. Ask us for a quote.
- Leaking joints in shower rooms and changing areas
- Leaks from showers into rooms or ceilings below
- Mouldy bathrooms flagged at a tenancy check
Commercial sealant in Underhill, done properly
Office kitchens, staff washrooms and welfare facilities need to be usable every working day. We can plan the work for early mornings or out of hours to keep disruption down. Each area is handed back with its cure time. Common call-outs are for repeated reseals that don’t last and large numbers of bathrooms needing the same work, across hotel bathrooms, welfare facilities and retail & leisure sites.
Commercial work in London comes with its own logistics: loading restrictions, building rules and tight access. Timings and access are agreed with the building before work starts in Underhill, and room-by-room programmes can be planned where needed.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Underhill (EN5, N20)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Why it’s worth doing now in Underhill
A leaking shower in a hotel room or flat above can damage the ceiling below. Then two rooms are out of action, not one. A reseal now avoids that. Damp from a failed joint spreads quietly in older London brickwork and timber, and by the time it shows on a wall or ceiling in Underhill, the repair is bigger than the sealant job would have been.
Combining jobs into one visit is generally more efficient than separate visits. We’ll send you a clear quote for the lot.
Why choose Mr Mastic in Underhill
- More than 20 years in sealant work
- Homes, businesses and hotels
- Tidy, careful work
- One-year guarantee on every job
Take a look at what affects the cost and customer reviews.
Aftercare tips
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Log resealing so you know what’s due
- Include the silicone on your room checklists
- Plan resealing around quiet periods
- Get split or lifting joints looked at early
A squeegee in each shower is a simple help: less water sits on the joints between uses.
Watch for the warning signs: black spots in the silicone, corners lifting, staining on the ceiling below or a musty smell. Any of these means the joints need attention.
What we do, step by step
Good joint work is mostly preparation, so that’s where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it normally takes a few hours per area, with larger sites planned over several visits. In a London area like Underhill, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- We walk the site with you and agree the rooms, the order and the hours.
- Each area is protected and the old sealant cut out completely.
- The joints are degreased, treated and left to dry.
- We lay the right sealant for each area, with anti-fungal silicone in wet rooms.
- Rooms are checked and returned with a cure time so staff know when to use them.
Before we arrive
- Keep children and pets away from the work area
- Try not to wet indoor joints just before the visit
- Move anything stored near the joints
Getting a quote
We quote each job on its own, so the first step is telling us about yours. Just phone 0345 464 0079 or email us with the details and send photos if you have them.
Related advice
What we are called out for in Underhill
Staff kitchens and food areas see constant splashing and wiping, and grease and cleaning sprays break down sealant. The worktop and sink edges usually fail first.
Most people get in touch when they notice something like this:
- Repeated reseals that do not last
- Washroom sealant that looks dirty however often it’s cleaned
- Failed floor-level joints in accessible wet rooms
- Tired sealant in let properties
For landlords with property near New Barnet station, several rental properties can be resealed on one programme.
What to look for in a quote
- Is VAT in the price?
- Whether all the old sealant comes out first
- Which sealant they’ll use, and why
- Are they insured?
What the job involves on each surface
Rental portfolios
An empty property is easy to reseal, so the next tenant moves in to clean, sound joints.
Welfare facilities
Shower rooms in welfare blocks get heavy use and need sound joints. Anti-fungal sanitary silicone is used throughout, including accessible wet rooms.
Commercial sealant in Underhill: local notes
Many London buildings have tight access and loading restrictions, and out-of-hours working is possible to arrange. London’s water is hard, so limescale builds up on sealant, grout and fittings.
If you look after a building such as St Catherine's RC School, busy washrooms and kitchens can be resealed in phases so they stay open. Community buildings like St John the Baptist Church are part of the picture too: any kitchen and washrooms need the same sealant care as any other building.
Underhill is about 1 mile west of Barnet, in Greater London. Every kind of property in Underhill can book us for commercial sealant. The work is guaranteed for a year. We cover 764 towns and villages across Greater London, large and small. For nearby work, see our London page (11 miles or so).
Every address in EN5 and N20 is covered for commercial sealant, from the main roads to the quietest streets. Whether your property is on Park Road, May's Lane and Manor Road or a nearby road, our applicators can take on the job. We also cover the places around Underhill: Barnet (1 mile east), New Barnet (1 mile east), Monken Hadley (1 mile north), Hadley Wood (1 mile north-east) and Cockfosters (2 miles east). We also work in nearby towns such as London (11 miles south-east), City of Westminster (9 miles south), Marylebone (9 miles south), Kensington (10 miles south), St Pancras (9 miles south) and Shoreditch (10 miles south-east).
What’s near Underhill
In Underhill, that means homes and buildings near Susi Earnshaw Theatre School, Highlands Gardens and The Red Lion pub and the streets around them. The closest station to Underhill is New Barnet station, about 1 mile east of the centre. Well-known places in the area include Francis Skaryna Belarusian Library and Museum (2.2 miles south) and Barnet General Hospital (0.9 miles west). For a walk, there’s Greenhill Gardens and Darland's Lake.
Towns and villages near Underhill
More services for Underhill
Common questions in Underhill
Do you work for landlords with property near New Barnet station?
Yes, landlords and agents are among the people we work for, 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’ll give you a clear price.
Is parking an issue for commercial sealant in Underhill?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
What sealant do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
Can you supply method statements and risk assessments?
Tell us what your site asks contractors for. We will confirm what we can supply before work is booked.
When can guests or staff use the shower again?
Follow the cure time we give you, which is normally around 24 hours. Planning the order of rooms keeps that downtime manageable.
Do you come to Underhill?
Yes. From our base in Crawley, we cover South East England, London and all of Scotland, Underhill included.
Do you offer different sealant colours?
We help you choose a colour that suits, from white and clear to greys and other shades. The product needed can limit the range.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
What we can’t put right
We will always be straight with you, so here’s what sealant cannot fix:
- Fire risk assessments or certification
- Cracked trays or baths rather than failed joints
- Failed tanking or loose tiles behind the sealant
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think.
Joints and surfaces we work on
- Student & care accommodation
- Welfare facilities
- Rental portfolios
- Office washrooms & kitchens
- Hotel bathrooms
- Retail & leisure sites
Quotes for commercial sealant in Underhill
We do not publish a price list. What we look at:
- The old material and how stubborn it is
- The product the joint needs
- Whether there’s mould to deal with
- When we can work, for business premises
Leaving a failed joint generally makes the job bigger, not smaller, as water and mould keep getting in. If you are not sure whether it needs doing, call 0345 464 0079 or email us and we’ll give you an honest view and a quote.
Asking for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- Whether it’s a home or a business
- Any access issues, like height or stairs
- The address or postcode of the job
- Roughly how big the job is
To get a quote, call 0345 464 0079 or send us an email with the location and a short description of the problem. You will have a clear quote before work begins.