Hertfordshire · England
Fire Rated Sealant in Northaw Valley
We cover Northaw Valley for intumescent and fire-rated sealant around gaps, frames and service penetrations. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Sealant items on a fire risk assessment action list
- Standard silicone or caulk in a fire-stopping gap
- Unsealed gaps where pipes and cables go through a wall
Workplaces and buildings in Northaw Valley
In England, the Regulatory Reform (Fire Safety) Order 2005 requires a fire risk assessment for workplaces and for the common parts of blocks of flats, which is often where open fire-stopping gaps are first noticed. We work to the specification you are given, installing the product to its tested details.
Rented homes near Crews Hill station change hands often, and any gap left by new services in shared walls should be closed with a fire-rated product. For site and facilities teams at buildings such as St. John's Senior School, fire-stopping around service openings should be restored whenever new services go in.
Northaw Valley is about 2 miles east of Potters Bar, in Hertfordshire. We carry out fire rated sealant for homes and businesses in Northaw Valley and nearby, as part of our work across Hertfordshire. 381 places in Hertfordshire are on our list, large and small. For nearby work, see our London page, about 14 miles away.
All of EN6 is covered for fire rated sealant, from the main roads to the quietest streets. Other places close to Northaw Valley include Botany Bay (1 mile south-east), Potters Bar (2 miles west), Hadley Wood (3 miles south-west), Bentley Heath (3 miles west) and Cockfosters (3 miles south). Larger places within reach include Watford (11 miles west), Hemel Hempstead (14 miles west), Stevenage (15 miles north), St Albans (9 miles north-west), Welwyn Garden City (8 miles north) and Harpenden (12 miles north-west).
What’s near Northaw Valley
Around Northaw Valley, our work takes us to homes and buildings near Two Brewers Public House, Northaw Church of England Primary School and Mount Grace School, among other places. Northaw Valley’s nearest station is Crews Hill station, roughly 1.4 miles south-east. Well-known places in the area include Spires Shopping Centre (3.8 miles south-west) and Chase Farm Hospital (2.3 miles south-east). For a walk, there’s Bowyer's Water and Fir and Pond Woods.
Fire rated sealant in Northaw Valley
Fire stopping only performs as intended if it’s done to the detail: the right depth, the right backing and the right product for the substrate. That detail is what we take care over. If you have linear gaps at the head of walls and open gaps behind door architraves, we can put it right.
For a small place like Northaw Valley, the journey and timings are agreed in advance, so the job can fit around bookings, guests or opening times where possible.
Whatever the size of the job, you get the same 12-month guarantee.
- Location
- Northaw Valley (EN6)
- Region
- Hertfordshire
- Cover
- One year on every job
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Looking after it afterwards
A little care helps the new joints last. Our advice:
- Do not fill fire-stopping gaps with ordinary foam or silicone
- Include hidden areas like risers in routine checks
- Tell trades working in the building that fire seals must be put back
- Get damaged fire seals looked at promptly
Follow the cure time we give you before decorating over the sealant. Not every fire-rated sealant takes paint and we will tell you which one you have.
An open gap is not only a fire issue: noise, draughts and even pests can come through too. Sealing them early helps on every front.
Can I do it myself?
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
How we quote for fire rated sealant
Your quote is based on your job. We look at:
- The number and length of the joints
- How easy the joints are to reach
- The product the joint needs
- How many areas need sealing
We don’t show prices on the website, because each job is priced on what it involves. Call for a quick quote and we’ll talk you through it.
What we need to know
What to tell us when you ask for a quote:
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it has been sealed before
- The rough size of the job
- Photos by email, if that is easy
Every job is quoted individually, so the first step is telling us about yours. Just phone 0345 464 0079 or drop us an email with the details.
Northaw Valley questions
Can you do fire rated sealant in Northaw Valley?
Yes. Our work covers London and the South East, and Northaw Valley is part of that. You can phone 0345 464 0079 or send us an email and let us know what needs doing.
Do you cover smaller places like Northaw Valley?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
What do you put in the joint?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Is it messy?
We keep the work tidy. We protect what’s around the joints.
Are you fully insured?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Will we have a record of what was sealed?
Yes. Every gap we seal is listed with the product used so it’s there for the next inspection.
Do the sealants smell?
Possibly a little. It fades as the sealant cures.
Where is Mr Mastic based?
Our base is Crawley, with over 20 years’ experience. We work across South East England, London and Scotland.
When to call us in Northaw Valley
Sealant applied too thin, without the backing its detail needs, or onto dust won’t perform as it was tested. Rushed fire stopping is common particularly when it was the last job before handover.
The most common problems we see are:
- Holes left by a change of layout
- Fire stopping disturbed by later work
- Gaps around pipes and cables through fire-resisting walls
- Unsealed gaps around fire door frames
For buildings such as Parish Church of St Thomas A Becket, gaps around pipes and cables are worth checking after any building work there.
What your quote should include
- Whether VAT is included
- How long the guarantee is
- Who does the work, and how experienced they are
- What the cure time is
Landlord and commercial work in Northaw Valley
Landlords and letting agents in Northaw Valley can book us as well as householders. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can go on one quote.
Also near Northaw Valley
More services for Northaw Valley
What the job involves on each surface
Linear gaps
Long, narrow gaps appear where walls meet slabs and ceilings. We seal them to the tested detail, with backing where it’s needed.
Flats and HMOs
In flats and HMOs, the walls and floors between homes and common areas need sealing where services pass through. We work through the gaps on your assessment room by room.
The process
All our tools and materials come with us in the van, so there’s nothing for you to buy. Once we’ve agreed what’s being done, the area is protected and the work begins. It normally takes anything from a few hours to several days, depending on how many gaps there are. Somewhere as small as Northaw Valley, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- Access to each area is agreed so the work can run in order.
- Old, damaged or unsuitable sealant is removed.
- Dust and loose debris are cleaned from each gap.
- The fire-rated or intumescent sealant is applied and tooled to the tested detail.
- We record what was done and flag anything that needs a different system.
Preparing for the visit
- Clear items away from the joints we are working on
- Let us know about parking restrictions
- Keep children and pets away from the work area
How to get a quote
Getting a quote is simple: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job.