Mastic contractors in Finchley
Construction mastic in Finchley, backed by over 20 years in commercial sealing. Fully insured, with a 12-month guarantee.
- Sealant knocked or painted over by other trades
- Perimeter gaps outside the sealant’s range
- Snag items on joints that need redoing before handover
Construction mastic in Finchley
Send drawings, photos or a joint schedule, or tell us about the site, and we’ll come back with a fixed quote.
Construction mastic in Finchley, done properly
On a new build, the mastic package is one of the last trades through each area. We work as a mastic subcontractor to main contractors and developers with projects in Finchley, sealing plot by plot or floor by floor as areas are released. We work on brick and block movement joints, floor and skirting junctions and sanitary and kitchen joints, and what we are called in for most is a long mastic snag list close to completion and bath and shower joints scraped during the final clean. Sealant applicators who only do sealant are a different proposition from a general trade with a gun in the van: in Finchley, that means joint design, primers and backing rod as standard.
Construction in a London area such as Finchley means working on constrained sites: limited storage, booked deliveries and access shared with other trades. Mastic is typically one of the last trades on each elevation or floor, so we keep to the programme and the order of trades the site sets.
Work we carry out in Greater London comes with a 12-month guarantee. If an installation problem shows up, call 01277 525 020 or email a schedule or drawings and we’ll arrange a return visit.
- Location
- Finchley (N3, N2, N12, NW11)
- Wider area
- Greater London
- Cover
- 12 months on every job
- Quote
- A fixed quote before we start
- Telephone
- 01277 525 020
- Page updated
- 3 November 2026
Keeping the joints sound
Cleaning and maintenance staff play a part too. Pass these on to them:
- Flag uneven or tapered frame gaps early
- Don’t force external sealing on a damp or frosty day
- Release areas for mastic once other trades have finished in them
- Keep finished joints away from paint, plaster and scrapers
Tell the builders’ clean team which areas have new sealant. Scrapers used on frames and worktops can nick or lift a new bead so keep them off the joints.
Snag items left to the last week put handover at risk. A planned close-out through each area as it completes keeps the list short.
Questions about Finchley
Can work at a site such as Middlesex University fit around teaching?
Yes. Education sites normally want the work in vacations or in phases during term, and we plan to suit. We are CHAS accredited and a Constructionline member, and paperwork such as RAMS is confirmed with the quote.
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. Say when the building is occupied and when it’s quiet, and we’ll plan accordingly. All of Greater London is inside the ULEZ, and our planning allows for it
Can you send site paperwork?
Each site asks for different documents, so list what you need, whether RAMS, insurance or CSCS details, and we’ll confirm with the quote.
Are you insured?
Yes. We’re fully insured, and the certificate can go with your quote.
Are you CHAS accredited?
We’re CHAS accredited and a Constructionline member, and each applicator is CSCS-carded. We’re fully insured for public liability.
Can one quote cover more than one building?
Yes. Multi-site work and planned programmes are a core part of the service, planned site by site to suit how each building is used.
Do you seal on top of existing sealant?
No. We cut the old material out and clean the joint back before sealing, because fresh silicone will not bond with aged silicone.
Common problems we fix in Finchley
Shrinkage and settlement in the first months put new joints under strain. Materials lose construction moisture and shrink, which opens up internal joints, particularly where caulk has been used in a joint that moves. Picking a flexible sealant where there’s movement keeps snags down.
What tends to prompt an enquiry:
- Internal caulk splitting as the building dries out
- Frame gaps too wide for sealant alone
- A long mastic snag list close to completion
- Bath and shower joints scraped during the final clean
For contractors at a school such as Manorside Primary School, sealing has to be finished before term starts.
Questions to ask before you book
- Whether primer will be used where the manufacturer specifies it
- Can the work be phased to keep areas open?
- Their approach to joint depth and backing
- Which product they’ll use, and why it suits the joint
Diagnose, treat, sign off
Diagnose, treat, sign off: that’s the shape of every visit. First comes an inspection and agreement on scope, then the work is carried out to the specified product and detail, and the job ends with a walk round and sign-off. Planning a London job such as one in Finchley starts with access. Give us the hours we can be on site and we will schedule to suit.
- Drawings, the sealant specification and your programme come to us for pricing.
- A fixed quote sets out the scope, the products and the sequence.
- Any site paperwork you need (RAMS, insurance certificate, CSCS details) is confirmed with the quote.
- Areas are sealed plot by plot or floor by floor as the trades hand them over.
- Joints are cleaned, primed where the maker requires it, backed and sealed to the specification.
- Before handover, snags are dealt with and the package is signed off under our 12-month guarantee.
Preparing the site
- Arrange parking or a loading space
- Confirm the product named in the specification
- Send asbestos survey details if the building is pre-2000
Get a fixed quote
Tell us about the building, the joints and when you need the work done, and a fixed quote will follow. The easiest way is to ring 01277 525 020 or use the quote form.
Related advice
Places near Finchley
Other services in Finchley
Building and refurbishing in Finchley
As part of Greater London, Finchley is inside the ULEZ, which applies to every van on site. Deliveries are booked and storage is tight, so mastic materials come in as needed. A 2-mile radius around Finchley takes in a good number of hotels. Hotel extensions and refits usually have to fit around bookings, so mastic dates are tight.
Building work at universities like Middlesex University (to the west of Finchley) is often timed for the summer, mastic included. When units on a site such as Finchley Industrial Centre (to the north of Finchley) are refurbished or reclad, the panel joints and window perimeters are part of the mastic package.
Finchley is about 6 miles north of City of Westminster, in Greater London. Anywhere in N3, the process is the same: details in, fixed quote out, then sealing and a 12-month guarantee. Our Greater London coverage takes in 764 places, large and small. Our London page has more on work in that area.
Commercial sites across N3, N2, N12 and NW11 are covered. We cover commercial and managed buildings on Station Road, Chaplin Square and Market Place. You’ll find Finchley on or near the B1462. We also cover Church End (1 mile west), Woodside Park (1 mile north), North Finchley (1 mile north), Friern Barnet (2 miles north-east) and Oakleigh Park (2 miles north). A short drive away, we cover London (8 miles south-east), City of Westminster (6 miles south), Marylebone (6 miles south), Kensington (7 miles south), St Pancras (6 miles south-east) and Shoreditch (7 miles south-east).
Near you in Finchley
Locally, jobs take us to sites close to The Elephant Inn, Bishop Douglass School and Francis Skaryna Belarusian Library and Museum and the streets around them. Nearby too are Victoria Park (under half a mile north) and Woodhouse College (1 mile north-east). The nearest railway station is New Southgate station, about 1.9 miles north-east. Other landmarks nearby include Finchley Memorial Hospital (under half a mile north-east) and Grand Arcade (1 mile north). Not far away are Highgate Hill and Lakeside Nature Reserve.
How the job changes by surface
Internal decorators’ caulk
Caulking is often done in a hurry by whoever’s on site. Done properly, it saves decorators time and gives a clean line.
Snagging before handover
Damaged, missed or untidy joints make up most snag lists. We price snagging as part of the package or as a separate visit.
What happens if it’s left?
Refurbishments sometimes budget for new windows when the frames are sound and only the seal has failed. Sound frames often need only a new perimeter seal and that’s a far smaller job. We will say so if a frame itself is the problem. In a London building, a failed joint rarely affects only one party: water travels through shared structures, and a small leak becomes a dispute between occupiers. Dealing with it early is simpler for everyone.
The price depends on the quantity of joints, what has to come out first and the access. Call for a quote when you’re ready.
Why clients in Finchley choose us
- One number for every site we cover
- Sealing commercial buildings since 2005
- CHAS accredited
- Colour agreed before work starts
Take a look at what affects the cost or our accreditations.
Building owners, agents and FMs in Finchley
For main contractors, we work as the sealant subcontractor on new-build and refurbishment projects. We work to your programme, your specification and your site rules, with CSCS-carded applicators on site.
Facilities managers want contractors who arrive with the paperwork sorted. Let us know the documents you need (RAMS, insurance certificate, CSCS details) and we’ll confirm them with the quote.