Fire stopping in Underhill
Fire-rated and intumescent sealing of service penetrations and linear gaps in Underhill and across Greater London. CHAS accredited, Constructionline member, with a 12-month guarantee on workmanship.
- Head-of-wall gaps with no fire seal
- Builders’ foam or ordinary silicone in compartment walls
- Openings left by services added after handover
Fire stopping for businesses in Underhill
Share the site address and what’s failing, and we’ll reply with a fixed quote or arrange a visit.
Service penetrations in Underhill buildings
A number of hotels sit less than 2 miles from Underhill. In hotels, bedroom and corridor walls are normally fire-resisting, so services added in a refit need sealing with the specified product. Approved Document B is the English guidance that covers fire stopping around openings and penetrations. Its BS 476 references are being withdrawn from 2 September 2029, with BS EN 13501-2 classification taking over, subject to transitional arrangements. Either way, we install the specified product to its tested detail.
Where a unit on an estate such as Hadley Manor Trading Estate (0.5 miles north of Underhill), has fire-resisting walls between offices and warehouse, any new service through them should be sealed to the tested detail. In a retail centre such as Spires Shopping Centre (0.7 miles north-west of Underhill), any fire-resisting wall between units that is crossed by new services needs sealing to the tested detail.
Underhill is about 1 mile west of Barnet, in Greater London. Looking for fire stopping in Underhill? We can help, as we do across Greater London. 764 places across Greater London fall within our area, Underhill among them. We also cover London, some 11 miles away.
Commercial sites across EN5 and N20 are covered for service penetrations. If your site is on Park Road, May's Lane and Manor Road or close by, we can quote for service penetrations. Close to Underhill, our area also takes in 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). Nearby towns on our patch include 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).
Around Underhill
We work on buildings around Susi Earnshaw Theatre School, Highlands Gardens and The Red Lion pub. Underhill’s nearest station is New Barnet station, roughly 1 mile east. 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). The countryside around Underhill includes Greenhill Gardens and Darland's Lake.
About our fire stopping in Underhill
A lot of fire-stopping work comes after M&E installation, a refit or a tenant fit-out. New cable runs, replaced pipework and extra data routes all punch holes in compartment walls, often unnoticed. Those on your schedule are closed with the specified product. If you have openings left by services added after handover and snag lists that include open service penetrations, we can put it right, whatever the surface. Most enquiries from Underhill start with one failed joint and grow into a wider look at the building: we look at the rest while we are there and tell you what we find.
In a London area such as Underhill, buildings are refitted often, and every new cable, pipe or duct through a fire-resisting wall or floor leaves a gap. Each service penetration gets fire-rated or intumescent sealant if that’s what is specified, laid to the product’s tested arrangement.
Every job ends the same way: guaranteed. You get a 12-month guarantee on our workmanship, and we explain exactly what that covers when we quote.
- Where
- Underhill (EN5, N20)
- Wider area
- Greater London
- Guarantee
- A 12-month guarantee
- Quotes
- Fixed quote, scope in writing
- Phone
- 01277 525 020
- Page updated
- 3 November 2026
When it isn’t the sealant
Honesty saves time and money. New sealant won’t cure:
- Fire doors, dampers or other fire safety equipment
- Deciding what a wall or floor needs, which belongs to the designer
- Issuing fire ratings or certificates for seals
Not sure which it is? You can call the office on 01277 525 020 or email a schedule or drawings and we’ll tell you honestly.
Surfaces we seal
- Joints between fire-resisting walls and floors
- Cable penetrations
- Small duct penetrations where the tested detail allows
- Pipe penetrations
- Service gaps in risers
- Linear gaps at wall heads
Cost factors for service penetrations
The price varies from site to site. Expect it to depend on:
- Which sealant the job calls for
- The site’s rules and procedures
- Whether the work must be split into stages
- Travel to remote or island sites
The specified product makes a difference, and so does the preparation. Access, phasing and site requirements come into it too.
Details that help us quote
To price the job accurately, we need to understand the site. Useful things to include:
- Specification clauses that apply
- Rough lengths or quantities, or drawings if you have them
- Whether an asbestos survey exists
- Your programme or deadline
Specifications, drawings and tender packages are welcome with any enquiry, and we’ll price against exactly what is specified. Smaller jobs need nothing more than photographs and a few notes.
Should maintenance staff do it?
Redoing a failed joint typically costs more than getting it right at the outset, because the whole bead must be removed and the faces cleaned back again. That’s why many clients bring in a specialist from the beginning.
For a quick touch-up, site staff may be fine, but larger jobs are different: a specialist brings efficiency, a consistent finish and a 12-month guarantee.
On site: what to expect
On arrival, we sign in, go through any site induction and check how permits are handled. Everything around the joints gets protected before anything is cut or cleaned, with the work itself normally taking anything from one day to a planned run of visits, depending on the number of seals and the access. Most London premises stay occupied while we are on site, so zones and timings are agreed with whoever manages the building. Phased work keeps the rest of the building in use.
- We start with your penetration schedule, drawings or specification.
- We plan the sequence of floors, risers and voids with you.
- We compare every service penetration with its tested detail before sealing.
- Foam, ordinary sealant and debris come out first.
- The specified backing and sealant go in to depth and are finished neatly.
- We tell you about openings that need a different product.
What we need from you
- Agree which areas must stay open
- Have the specification and drawings to hand
- Move anything stored against the joints
Ask for a quote
A handful of photos and a postcode is the fastest way to a quote. Upload them with the quote form, or speak to us on 01277 525 020 or email a schedule or drawings if you’d rather talk the job through.
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Signs you need fire stopping in Underhill
When a seal departs from its tested detail, the evidence no longer covers it. An oversized gap, too shallow a bead, missing backing or two makers’ products combined are the usual culprits.
It’s worth sending us details if you spot any of the following:
- Fire-rated sealant that has cracked or shrunk back
- Non-fire-rated filler around services
- Penetration schedules that need working through
- Unsealed penetrations discovered above suspended ceilings
Hospital estates such as Barnet Hospital (0.9 miles west of Underhill) are divided into fire compartments, and any service penetration through them should be sealed to the specified, tested detail.
Comparing quotes
- How they handle RAMS and site documents
- How the existing material will be dealt with
- Their public liability cover
- Whether primer will be used where the manufacturer specifies it
Also near Underhill
More services for Underhill
Underhill: questions and answers
Can you work around term dates at a campus such as Middlesex University?
Yes. Education sites normally want the work in vacations or in phases during term, and we plan to suit. Let us know which documents your site asks for, and we’ll confirm them alongside the quote.
Do you work in occupied care homes around Underhill?
Yes, with the manager deciding the order and timing of rooms. Noise and disruption are kept to a minimum.
Do you have public liability insurance?
Yes. We are fully insured, and the certificate can go with your quote.
Does weather matter for sealant work?
It can, when the joints are outside. Wet joints and cold, damp or frosty conditions stop the sealant bonding properly, so we watch the forecast and rearrange outside work if we have to. Indoors, the weather is rarely a problem.
How many days will you need on site?
We plan the time on site around your programme and access. You will have an expected duration with the quote.
Can you follow the specification on our project?
Yes. The specification and the manufacturer’s installation guidance are what we work to, and any queries are raised before we start.
Do you work in Underhill?
Yes. We cover Underhill. For a quote, give us a call on 01277 525 020 or email us.
Surface by surface
Masonry and concrete
Many seals are made in blockwork, brickwork or concrete slabs. Dust and debris are cleared from the opening, so the sealant and any backing sit properly.
Cables and cable bundles
Cable penetrations are frequently sealed with fire-rated sealant where the detail allows. The detail limits bundle size and the gaps between and around cables, so we check before sealing.