Fire-rated sealing and fire stopping in Langley, Hertfordshire
Fire-rated and intumescent sealing of service penetrations and linear gaps in Langley. CHAS accredited, Constructionline member, with a 12-month guarantee on workmanship.
- Expanding foam used as fire stopping
- Hidden openings found during inspections
- Old intumescent sealant that has split away
Fire stopping in Langley
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
Diagnose, treat, sign off
Before we leave any area, we remove the tape, clean down and inspect every joint with your site contact. If an area should be left alone while the sealant cures, we say how long and put signs out. If others near Langley need work, visits can be combined. You will have a fixed quote before work starts.
- First we confirm the product and tested details named in the specification.
- Openings are measured and grouped by detail.
- Old or wrong materials are cut out.
- Where the detail needs backing, it goes in at the stated depth.
- We gun the sealant in to the specified depth around each service and tool it.
- We walk the completed areas with you and confirm the records agreed at quote stage.
Preparing the site
- Let building users know which areas are affected
- Point out parking and an unloading spot
- Clear stock, furniture or equipment away from the joints
Ask for a quote
Photos, drawings or a schedule of the joints are often enough for a fixed quote. Where a site visit makes more sense, we will arrange one.
Related advice
Fire stopping for commercial buildings in Langley
We are commercial sealant applicators, CHAS accredited and a Constructionline member, with CSCS-carded applicators on site. We hold no third-party fire-stopping installer certificate and we’d rather say that up front. What we offer is careful installation of the specified sealant to its tested detail, with a 12-month guarantee on our workmanship. We work on joints between fire-resisting walls and floors, pipe penetrations and small duct penetrations where the tested detail allows, and the failures we are asked to look at most are expanding foam used as fire stopping and openings found when ceilings come down for a refit. Searching for sealant specialists in Langley? Mastic Doctor has worked for contractors, FMs and building owners since 2005, with CSCS-carded applicators.
Around smaller places like Langley, penetration seals come up in schools, halls, pubs with rooms, care homes and farm buildings used as offices. Any service penetration through those walls should be closed with the specified product, set out as its test evidence shows.
We stand by our work with a 12-month guarantee. It covers how we prepared and applied the sealant, and we come back if anything isn’t right.
- Where
- Langley (SG4)
- Wider area
- Hertfordshire
- Guarantee
- A 12-month guarantee
- Quotes
- A fixed quote before we start
- Call
- 01277 525 020
- Updated
- 3 November 2026
What sealant work can’t fix
We seal joints; we don’t mend everything behind them. On its own, sealant can’t deal with:
- Construction that lacks the fire resistance the seal relies on
- Fire doors, dampers or other fire safety equipment
- Large openings beyond what any sealant detail covers
If in doubt, speak to us on 01277 525 020 or send details through our quote form and we will say what we think.
Surfaces we seal
- Cable penetrations
- Pipe penetrations
- Joints between fire-resisting walls and floors
- Small duct penetrations where the tested detail allows
- Service gaps in risers
- Linear gaps at wall heads
Looking after the joints
Your facilities or cleaning team can help the joints last. Pass these on to them:
- File the specified details where the next contractor can find them
- Brief every trade that openings they make must be sealed
- Check with the data sheet before painting over fire sealant
- Flag new cables with no seal around them
After every round of M&E works, check that the openings created have been sealed. Building it into each contractor’s sign-off keeps the walls intact.
On fit-outs, get the fire-stopping specification agreed before the services go in. Details can then be picked to suit the actual pipes, cables and ducts.
Places near Langley
Also in Langley
Penetration seals near Langley
Fire stopping of openings and penetrations in England falls under Approved Document B. The national BS 476 classes are due to drop out of it from 2 September 2029, leaving the European BS EN 13501-2 route, subject to transitional arrangements. What we install is set by the specification, and it goes in to the tested detail. There are a number of hotels within about 2 miles of Langley. Bedroom-to-corridor walls in hotels are normally fire-resisting, so new cabling or pipework through them has to be sealed to the tested detail.
Schools such as The Thomas Alleyne School often have new data and services installed during holidays, and penetrations through fire-resisting walls should be checked afterwards. On a hospital site such as Lister Hospital, which lies north of Langley, fire-rated sealant goes in where the specification calls for it, with the work planned around the estates team’s permits.
Langley is about 3 miles south-west of Stevenage, in Hertfordshire. Any commercial site in Langley is covered, for single jobs and planned programmes alike. 371 places across Hertfordshire fall within our area, including Langley. London is covered too, around 27 miles from Langley.
We cover the SG4 postcode districts for service penetrations. For a building on London Road and Village Street or nearby, we can quote for service penetrations. If your building is just outside Langley, we cover Langley Bottom (1 mile north-west), Rush Green (1 mile north-west), St Paul's Walden (1 mile west), Old Knebworth (2 miles south-east) and Driver's End (2 miles south). Further afield, our area takes in Hemel Hempstead (13 miles south-west), Stevenage (3 miles north-east), St Albans (10 miles south-west), Welwyn Garden City (6 miles south), Harpenden (7 miles south-west) and Hitchin (5 miles north).
Around Langley
In Langley, that means premises near Concerts at Knebworth House and Farmers Boy Public House, among other places. For rail, the closest station is Stevenage station, roughly 1.5 miles north-east of the centre. Well-known places in the area include Lister Hospital (2.7 miles north) and Wymondley Castle (3.7 miles north). The countryside around Langley includes Ridlins Mire.
Questions we’re asked in Langley
Would you work within a site like Lister Hospital?
Yes. We work in healthcare settings as well as offices and schools. Before anything starts, the estates team agrees permits, inductions and infection-control measures with us.
Is Langley too far out for you?
Not at all. Langley is within our area. Our area covers London and the South East counties. Send photos and a list of what needs doing, and we’ll plan the job to need as few trips as possible.
Can you follow the specification on our project?
Yes. The specification and the manufacturer’s installation guidance are what we work to.
What site paperwork can you supply?
Each site asks for different documents, so list what you need, whether RAMS, insurance or CSCS details, and we’ll confirm with the quote.
Will you just go over the old sealant?
No. Failed sealant is removed and the faces cleaned back to sound, dry material first, because fresh silicone will not bond with aged silicone.
Do you have public liability insurance?
Yes. Mastic Doctor is fully insured, public liability included.
Is your workmanship covered by a guarantee?
Yes. It runs for twelve months and covers how we prepared and sealed the joints, but not damage, misuse or other trades’ work.
What happens if it’s left?
Open service penetrations matter on ordinary days, not just in a fire: smoke, noise and draughts pass through them every day. The specified fire seal closes the gap for all of these. Around Langley, it’s better to renew all the failing joints at once, rather than one at a time. Send photos of each area and we’ll quote for the lot.
Every site prices differently: the joint sizes, the specified product, access and working hours each have a bearing. Send the details and a fixed figure follows.
Why us?
- Products installed to the manufacturer’s instructions
- Commercial sealant work since 2005
- Fully insured
- Workmanship guaranteed for 12 months
Take a look at how commercial sealant jobs are priced and our accreditations.
Commercial clients in Langley
CHAS accredited and a Constructionline member, we make supplier vetting simple. Our insurance certificate can be sent along with the quote.
Whether you’re a managing agent, a property factor or an owner’s representative: send the details, accept a fixed quote, and we carry out and guarantee the work. Keys, access and contacts can be agreed in advance.
Signs you need fire stopping in Langley
Physical damage is another reason seals stop doing their job. Seals get knocked during maintenance, cut back to add a cable or pulled out when services are swapped and the opening isn’t always resealed.
Typical triggers for a call:
- Unsealed joints where partitions meet the slab
- Improvised or mixed-product fire seals
- Penetration schedules that need working through
- Fire-rated sealant that has cracked or shrunk back
On a site such as Horizon Technology Park (1.2 miles east of Langley), every fit-out that runs new services through a compartment wall leaves penetrations to seal with the specified product.
What to look for in a quote
- How joint depth will be controlled
- What site paperwork they can supply
- Which product they’ll use, and why it suits the joint
- How long is the guarantee, and what does it include?