Mastic sealant contractors in Friern Barnet
Planning work on a mastic joint in Friern Barnet? We assess it, carry out the work and guarantee our workmanship for 12 months.
- Repeated reactive repairs to the same buildings
- Estate-wide sealant that is simply worn out
- Patchy repairs in mismatched sealant
Mastic sealing for businesses in Friern Barnet
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
How we handle mastic sealing in Friern Barnet
Before work starts, most agents and landlords want the documents in order. Tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we’ll confirm with the quote. We’re a Constructionline member and CHAS accredited, and we carry public liability insurance. We work on balcony and threshold joints, communal kitchens and washrooms and shopfronts below residential blocks, and the failures we’re asked to look at most are movement joints with sealant missing and no planned programme for sealant. A single leaking joint is often how a building in Friern Barnet first comes to us: we look at the rest while we’re there and tell you what we find.
London’s ULEZ covers every borough, and parking and loading rules vary street by street. For a block or estate, it helps to know where we can park and stage materials.
We sign every job off with a 12-month guarantee. The promise is simple: if our work fails within that year, we put it right.
- Place
- Friern Barnet (N11, N12, N10, N20)
- Wider area
- Greater London
- Cover
- 12 months on every job
- Quote
- A fixed quote before we start
- Call
- 01277 525 020
- Last updated
- 3 November 2026
Honest limits
Some faults sit outside our scope, and we say so rather than covering them up:
- Leaks through the frame itself rather than the perimeter
- Substrate edges that need repairing first
- Glazing that needs replacing
If you’re not sure, just phone 01277 525 020 or use the quote form and we will give you a straight answer before you book.
Joints and surfaces we work on
- Communal entrances and stairwells
- Communal kitchens and washrooms
- Shopfronts below residential blocks
- External wall and movement joints
- Window and door perimeters on blocks
- Balcony and threshold joints
Looking after the joints
For the best life from the joints:
- Reduce knocks to communal area joints
- Avoid piecemeal callouts where you can
- Share the asbestos register when you send details
- Check sealant joints during planned building inspections
Protect entrance and corridor joints from knocks where possible. Damage at low level is the most common reason communal joints fail early.
Water getting in round frames can damage plaster, decoration and the frames themselves. Resealing early keeps the job small.
Why it’s worth doing now in Friern Barnet
Sealing over failed mastic looks tidy for a while. It doesn’t bond and usually fails within a short time. Full removal and proper preparation is what lasts. Failed sealant in a building in Friern Barnet can quickly affect neighbours, tenants or the floor below: water travels through shared structures, and a small leak becomes a dispute between occupiers. Putting it right early is less disruptive than dealing with the consequences.
The price depends on how many linear metres there are, how much old material needs removing and the access. Call for a quote once you have the details.
Why us?
- Colours chosen to suit frames, cladding or finishes where possible
- One phone line for London, the South East and Scotland
- 12 months’ guarantee on every job
- Joints cleaned back to sound surfaces
Read how commercial sealant jobs are priced and our accreditations.
Should maintenance staff do it?
Some joints are best left to specialists: for example fire-rated seals that must match a tested detail, trafficked floor joints and external movement joints. Getting these wrong normally costs more in the end than doing them right.
Redoing a failed joint normally costs more than getting it right at the outset, since all of it has to come out and the faces be cleaned back again. That’s why many clients bring in a specialist from the beginning.
Our process
The first thing on site is a walk round with your contact, to confirm the scope, the order of work and any areas we must keep clear. After that, any old or failed material is removed, each joint is prepared and the new sealant goes in. All of Greater London is in the ULEZ, and kerbside space in Friern Barnet can be scarce. If there’s a loading bay, a car park or a permit we can use, tell us when you send details.
- First we look at the mastic on each building and note what needs replacing.
- A fixed quote follows, split by block or building if that suits you.
- Dates, areas and access are agreed so residents or tenants can be told in advance.
- We remove the old mastic completely and clean the joint faces back.
- Backing rod and primer go in as the joint requires, then the new bead is placed and tooled.
- Finished joints are looked over and the 12-month guarantee confirmed.
What we need from you
- Share your working hours and any access restrictions
- Have the specification and drawings to hand
- Agree which areas must stay open
Request a quote
Pricing a project or setting a maintenance budget? Send the scope and any drawings, and we will return a fixed quote that you can work with. If you have questions first, give us a call on 01277 525 020 or email the details over.
Read more
Also near Friern Barnet
What else we do in Friern Barnet
Questions we’re asked in Friern Barnet
Is Friern Bridge Retail Park, near Friern Barnet, within your area?
Yes. Estates, retail parks and business parks around Friern Barnet, Friern Bridge Retail Park among them, are all within reach. A few photographs and the unit address let us price the work.
Can you work in a London building with booked loading and goods-lift slots?
Yes. Inductions, permits and timed loading are routine for us in London. The building manager’s rules go straight into our method. We allow for the ULEZ, which covers every borough
Who decides which product is used?
If the job is specified, we follow the specification. Otherwise, we recommend a product to suit the joint’s movement, the substrate and the conditions, following the manufacturer’s guidance.
Can you take on resealing for a block portfolio?
We do. Managing agents, property factors in Scotland, housing associations and landlords with block or commercial portfolios are our main clients for this work and work can be quoted per building or as a whole.
How long will the new sealant last?
Nobody can honestly give a figure in years, because life depends on how much the joint moves, how exposed it is and how it’s cleaned and used. Regular inspection is the best way to catch problems early.
Can you quote from photographs?
Photos, drawings or a schedule are often enough to quote. Where they aren’t, we arrange a site visit before quoting.
Can people stay in the building while you reseal?
Occupiers stay in the building throughout. We flag any areas that need internal access well before the dates so it can be arranged.
Mastic sealing in Friern Barnet: the local picture
There are six care or nursing homes within about 2 miles of Friern Barnet. Care home owners need frame and external mastic kept sound without unsettling residents. Blocks in London are normally run by managing agents, landlords or housing associations, with residents to notify and access to arrange. We work to your notice and access plan.
Site managers at schools like Holly Park Primary School can fit frame mastic into the summer works. If you own or manage units on a site such as Friern Bridge Retail Park, which lies east of Friern Barnet, failed mastic on frames, door surrounds and external joints can be dealt with unit by unit. Trustees of buildings like St John's Church can bring frame and external mastic into a planned maintenance list.
Friern Barnet is about 2 miles north-east of Finchley, in Greater London. Looking for mastic sealing in Friern Barnet? We can help, as we do across Greater London. Friern Barnet is one of 764 places in Greater London on our list. Our London page has more on work in that area.
Anyone looking for mastic sealing in N11, N12, N10 and N20 gets the same process as the rest of our area: send details, get a quote, we seal, guaranteed. For a building on Martock Gardens, Shapwick Close and Radstock Close or nearby, we can quote for mastic joints. You will find Friern Barnet on or near the A406 and B550. Just outside Friern Barnet, we also work in New Southgate (1 mile east), Brunswick Park (1 mile north), North Finchley (1 mile west), Arnos Grove (1 mile east) and Whetstone (1 mile north-west). A short drive away, we cover London (8 miles south), City of Westminster (7 miles south), Marylebone (7 miles south), Kensington (8 miles south), St Pancras (6 miles south) and Shoreditch (7 miles south-east).
Around Friern Barnet
Locally, jobs take us to sites close to Francis Skaryna Belarusian Library and Museum, Friary Park and Friern Barnet School, among other places. Friern Barnet has its own railway station: New Southgate station. Nearby you’ll also find Francis Skaryna Belarusian Library and Museum (1.4 miles west) and Grand Arcade (1 mile west). Not far away are Highgate Hill and Darland's Lake.
How the quote is worked out
A fixed quote reflects the actual work. It allows for:
- Whether old sealant has to be cut out first
- Quantities, in metres or numbers
- Induction, permit and paperwork requirements
- Travel to remote or island sites
We don’t publish prices, since every building and every scope is different. Call for a quote and we’ll price your job on its own details.
What to include in your enquiry
A good diagnosis starts with the right details. Tell us:
- Any specification or named product
- The site address and postcode
- Asbestos survey details if the building is older
- How the joints are reached, and at what height
For a fixed quote, call the office on 01277 525 020 or send details through our quote form, telling us the site location and the nature of the job. You can also send details through our quote form.