Hertfordshire · England
Northaw Fire Rated Sealant
Professional fire rated sealant in and around Northaw, with every bit of old sealant taken out first and a 12-month guarantee.
- Sealant items on a fire risk assessment action list
- Unsealed gaps around fire door frames
- Gaps around pipes and cables through fire-resisting walls
How to look after the new joints
Good habits help new joints last longer. Our tips:
- Never patch a fire seal with standard sealant
- Keep the record of products and locations with your fire safety documents
- Keep photos of seals that will be hidden
- Allow for resealing whenever new services are run
File the record of locations and products with your fire safety paperwork. It helps whoever checks the building next.
Any job that breaks through a wall or ceiling should include resealing. Doing it at the time avoids leaving gaps behind.
About our fire rated sealant in Northaw
Door frame gaps, linear joints and holes around services all have their own details. Measuring the gap and checking what it’s made of comes first, then apply it to the depth its tested detail calls for. We work on flats & HMOs, service penetrations and linear gaps, and the jobs we see most are gaps left after a refit or conversion and gaps around pipes and cables through fire-resisting walls.
In a village or hamlet like Northaw, commercial work is more likely to be a pub, a farm shop, holiday lets or a village hall than an office block. They all have washrooms, kitchens and service openings that need the right sealant.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- Northaw (EN6)
- Region
- Hertfordshire
- Guarantee
- One year on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Northaw: your questions answered
Do you cover Northaw for fire rated sealant?
Yes. Our work covers London and the South East, and Northaw is part of that. Just ring 0345 464 0079 or drop us an email with a few details of the job.
Do you work for landlords with property near Cuffley station?
Yes, we work for landlords and letting agents. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear quote.
Do I have to be there?
We need access to the joints, so we will agree that with you when we book. For inside work, that normally means someone being in.
What does fire rated sealant cost?
The cost depends on the size of the job, access and how much old sealant has to come out. Call for a quick quote and we’ll talk you through it.
What does intumescent mean?
Intumescent means it swells when heated, helping close the gap. Intumescent sealants are one kind of fire-rated sealant; which product suits depends on the gap, the substrate and the service.
Is it messy?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
Can you give us a record of the work?
Yes. Locations and products are written up when we finish. Tell us if your assessor needs it in a particular format.
How long does fire rated sealant take?
A typical job takes anything from a few hours to several days, depending on how many gaps there are, including preparation and clearing up. Your quote will say how long we expect yours to take.
What happens if it’s left?
Squirting in whichever sealant is nearest doesn’t make a fire seal. Fire-rated products are tested in set gap sizes, depths and substrates, so both the product and the method matter. Around Northaw, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why choose Mr Mastic in Northaw
- Homes, businesses and hotels
- We leave the area clean and tidy
- Old sealant always removed completely
- Trusted Arbo and Everbuild sealants
Read what affects the cost and customer reviews.
Commercial buildings in Northaw
Workplaces and the common parts of blocks of flats in England need a fire risk assessment under the Regulatory Reform (Fire Safety) Order 2005, which is often where open fire-stopping gaps are first noticed. We apply fire-rated sealant to the assessor’s or designer’s specification and the product’s tested details.
Rented homes near Cuffley station change hands often, and any gap left by new services in shared walls should be closed with a fire-rated product. For buildings such as Parish Church of St Thomas A Becket, older buildings that have had new heating or wiring often have service gaps worth checking. If you look after a building such as Northaw Church of England Primary School, fire-stopping around service openings should be restored whenever new services go in.
Northaw is about 2 miles north-east of Potters Bar, in Hertfordshire. We provide fire rated sealant to homes and businesses in Northaw and the surrounding area. Our area takes in 381 places across Hertfordshire. We also work in London, around 14 miles away.
All of EN6 is within our area for fire rated sealant, from the main roads to the quietest streets. If you need fire rated sealant at a property on Vineyards Road, Church Lane and Northaw Road West or a nearby road, we can help. Nearby, we also carry out fire rated sealant in Cuffley (1 mile east), Brookmans Park (2 miles north-west), Newgate Street (2 miles north-east), Bell Bar (2 miles north-west) and Little Berkhamsted (3 miles north). Further out, we also cover Watford (11 miles west), Hemel Hempstead (14 miles west), Stevenage (14 miles north), St Albans (8 miles west), Welwyn Garden City (7 miles north) and Harpenden (12 miles north-west).
What’s near Northaw
We work in homes and buildings around Two Brewers Public House and Mount Grace School and the streets around them. For rail, the closest station is Cuffley station, roughly 1.6 miles east. A little further out are Potters Bar Museum (2.1 miles west) and Chase Farm Hospital (3.3 miles south-east). Open spaces near Northaw include Fir and Pond Woods.
DIY versus a professional finish
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
What happens on the day
Before we leave, we go over the finished joints with you and tell you how long to leave it. The visit itself usually takes from a few hours to a few days, depending on the number of gaps and the access, depending on the size of the job. Somewhere like Northaw needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- Before starting, we go through the specification or action list with you.
- We measure every gap and note what it’s in and what passes through.
- Any non-fire-rated filler is removed and the gap cleaned.
- We fit backing where needed and apply the fire-rated sealant to depth.
- We hand over a list of locations and products for your files.
Preparing for the visit
- Move anything stored near the joints
- Mention any leaks or damp you’ve noticed
- Mention any tricky access
Getting a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is. Whenever you are ready, ring 0345 464 0079 or email us.
Related advice
Surface by surface
Linear gaps
A linear joint may need to allow for movement as well as fire. The product and depth are chosen to suit both.
Flats and HMOs
Conversions usually leave a mix of old and new service holes. We seal the ones on your specification with a tested product.
For landlords and businesses
Letting agents and landlords in Northaw can book us as well as householders. Resealing between tenancies keeps a property looking cared for before the next move-in.
For anyone letting property in or around Northaw, several properties can be quoted together. Just tell us the addresses and what each one needs, and photos by email help.
Nearby places to Northaw
More services for Northaw
What we cannot put right
New sealant can’t fix everything, and we’d rather say so up front. It will not solve:
- Problems with the door itself rather than the gap around the frame
- Sign-off of the building, which sits with building control or your assessor
- Deciding what fire stopping a building needs
If you are not sure, just phone 0345 464 0079 or drop us an email and we will give you a straight answer.
What we seal
- Plasterboard & masonry
- Linear gaps
- Door frames
- Flats & HMOs
- Service penetrations
- Pipe & cable gaps