Mastic sealant contractors in New Barnet
Mastic sealing for building owners, managing agents and housing associations across New Barnet, carried out by CSCS-carded applicators. CHAS accredited and fully insured.
- A mix of products and colours from past repairs
- Window mastic that has split and shrunk
- Mastic failing across several blocks on an estate
Mastic sealing for businesses in New Barnet
Photos, a specification or a quick description of the joints is enough to start a fixed quote.
Mastic sealing in New Barnet, done properly
Older blocks and commercial buildings can have mastic that contains asbestos. Before we disturb it, we ask to see the asbestos register or survey, and work stops for testing if there’s any doubt. We don’t remove asbestos-containing materials. Site teams most often ask us about a mix of products and colours from past repairs and cracked, hardened mastic round windows on a block, on shopfronts below residential blocks, window and door perimeters on blocks and communal kitchens and washrooms. One point of contact handles commercial sealant work in New Barnet from the first photographs to the final walk-round, whether it’s one building or several.
Across Greater London, New Barnet included, the ULEZ applies, and parking and loading rules differ from street to street. For a block or estate, it helps to know where we can park and stage materials.
Building owners and contractors get the same cover: a 12-month guarantee on our workmanship. It doesn’t extend to damage, faults in the building or work by others, and we are upfront about that.
- Location
- New Barnet (EN5, EN4, N20)
- Wider area
- Greater London
- Guarantee
- A 12-month guarantee
- Price
- A fixed quote before we start
- Telephone
- 01277 525 020
- Last updated
- 3 November 2026
Blocks and managed buildings in New Barnet
New Barnet has seven care or nursing homes no more than 2 miles away. Frame mastic on care buildings is best renewed elevation by elevation, with the manager deciding timings. For a London block, the agent or landlord usually handles notices to residents and access to flats. We plan around the notices and access you arrange.
Owners of student blocks near Middlesex University, 4.5 miles to the south-west of New Barnet, can schedule frame and external mastic for the summer vacation. Buildings close to stations like New Barnet station (to the north of New Barnet) are often flats over shops, with frame mastic to keep sound. If you’re responsible for a building such as Holy Trinity Lyonsdown, frame and door mastic needs the same attention as any other property.
New Barnet is about 1 mile east of Barnet, in Greater London. We cover commercial sites throughout New Barnet. 764 places across Greater London fall within our area, New Barnet among them. For work in that direction, see our London page, about 11 miles away.
Anyone looking for mastic sealing in EN5, EN4 and N20 gets the same process as the rest of our area: details, then a fixed price, then sealing and a 12-month guarantee. Streets here include York Road, Park Road and Henry Road, and sites on any of them can send details for a fixed quote. Close to New Barnet, our area also takes in Barnet (1 mile west), Cockfosters (1 mile north-east), East Barnet (1 mile south-east), Underhill (1 mile west) and Whetstone (1 mile south). Further afield, our area takes in London (11 miles south), City of Westminster (9 miles south), Marylebone (9 miles south), Kensington (10 miles south), St Pancras (8 miles south) and Shoreditch (9 miles south-east).
Around New Barnet
Locally, jobs take us to sites close to Trent School Cockfosters, East Barnet School and The Alexandra pub. New Barnet has its own railway station: New Barnet station. A little further out are Spires Shopping Centre (1.6 miles north-west) and Francis Skaryna Belarusian Library and Museum (2 miles south). The countryside around New Barnet includes Greenhill Gardens and Darland's Lake.
Also near New Barnet
What else we do in New Barnet
On site: what to expect
A typical day starts with protection: masking tape along the joint edges and sheeting over anything nearby. On site, the work usually takes anything from a day to a few weeks, depending on the number of buildings and joints, and we clear our waste as we work. Most London premises stay occupied while we are on site, so we agree zones and timings with the building or facilities manager. Phased work keeps the rest of the building in use.
- First we look at the mastic on each building and note what needs replacing.
- You get a fixed quote, priced per building where that helps your budgeting.
- The programme is fixed with you, including dates you can pass on to residents or tenants.
- Failed mastic is removed and the faces taken back to sound, dry material.
- Deep joints get backing rod, faces are primed if the manufacturer specifies it, then the joint is sealed and tooled.
- Finished joints are looked over and the 12-month guarantee confirmed.
What we need from you
- Have the specification and drawings to hand
- Explain the parking and delivery arrangements
- Warn occupants and staff about the work
Quotes
Pricing a project or setting a maintenance budget? We’ll quote against your scope and drawings you can plan around. For a chat about it beforehand, ring 01277 525 020 or email a schedule or drawings.
Read more
Keeping the joints sound
Once the work is signed off, these steps help:
- Mention RAMS, insurance or CSCS requirements up front
- Look at the sunniest and most exposed elevations first
- Plan resealing building by building rather than complaint by complaint
- Track which buildings were done and when
If paintable sealant was used, decoration can follow once it has cured. Non-paintable silicone shouldn’t be painted over.
Failed mastic often goes unnoticed until heavy rain finds it. Resealing when cracking first shows avoids water damage and saves internal repairs.
What happens if it’s left?
Adding sealant to cyclical maintenance is an easy win. Leaving it until there’s a leak turns it into reactive work and less choice about when. In New Barnet, each extra visit means more notices, permits and disruption, so a proper job first time, with the old sealant fully removed, is worth it.
We don’t publish prices, because the scope varies so much from one building to the next. For a fixed figure, call for a quote and we’ll price your job on its own details.
Why us?
- Work to your specification and the manufacturer’s guidance
- Health and safety: CHAS accredited
- Fully insured, including public liability cover
- Colour options checked against the specified product
See how commercial sealant jobs are priced or how we’re accredited.
FAQs: New Barnet
Can you cope with the access rules in a London building?
Yes, most London buildings have access rules of some kind, and we plan around them. Share the building’s contractor rules and we will work to them. All of Greater London is inside the ULEZ, and our planning allows for it
Do you work in occupied care homes around New Barnet?
Yes. We work around residents’ routines, a room or two at a time. Noise and disruption are kept to a minimum.
Does the weather affect the work?
For external joints, yes. Sealant needs a dry joint and a temperature within the product’s range, so frost, rain or cold mornings can delay outside work. Internal work is rarely affected.
Can you reseal a whole block or estate?
We can. Each building is inspected, quoted and scheduled in turn, and the programme can start with the worst.
How do you reach windows on upper floors?
Every block is different. How upper joints are reached is agreed before work is booked so the fixed quote reflects it.
How long before the joints can be used?
That comes down to the sealant and the temperature. Some products skin over quickly but need longer to cure fully, and we confirm it before leaving site.
Is it fine to apply new sealant on top of old?
No. Failed sealant is removed and the faces cleaned back to sound, dry material first, because fresh silicone will not bond with aged silicone.
When something else is needed
Sealant solves a lot, but not everything, and we’d rather tell you before you spend money. It won’t fix:
- Materials that need asbestos testing before work
- Water coming in from the roof or rainwater goods
- Masonry that has broken away beside the joint
If you are not sure, just speak to us on 01277 525 020 or email the details over and we’ll give you a straight answer.
Surfaces we seal
- Window and door perimeters on blocks
- External wall and movement joints
- Communal kitchens and washrooms
- Shopfronts below residential blocks
- Communal entrances and stairwells
- Balcony and threshold joints
Commercial clients in New Barnet
Housing associations and managing agents often need work done across blocks and communal areas. Work can be phased so residents and staff keep access throughout, with each stage agreed with your site contact.
If you look after buildings for someone else, you need clear quotes and clear reporting. We quote a fixed sum, confirm the scope and walk the finished work with you or your representative.
What sets the cost
To price the job, we consider:
- How accessible the joints are
- Joint width, depth and condition
- The site’s rules and procedures
- Travel to remote or island sites
A quote for mastic joints depends on quantities, condition and access, and any specification that applies. Ask us for a fixed quote.
Details that help us quote
There’s no need for a formal survey. A few details are enough to get going:
- The type of building and who uses it
- The site address and postcode
- A wide shot and a close-up of the area
- Approximate linear metres or a joint schedule
Every job follows the same four steps: send details, get a quote, we seal, guaranteed. The first step is to speak to us on 01277 525 020 or send photos by email with what you know.