Greater London · England
Fire Rated Sealant in Dartmouth Park
Intumescent and fire-rated sealant around gaps, frames and service penetrations for homes and businesses in Dartmouth Park and across Greater London. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Open joints along the top of partitions
- Cracked or shrunken fire-rated sealant
- New service routes left unsealed after building work
About our fire rated sealant in Dartmouth Park
We can work through a building room by room or floor by floor, with each location and product recorded. It gives you a list to keep with the building’s fire safety documents. We are often asked to deal with unsealed gaps around fire door frames and sealant items on a fire risk assessment action list, across door frames, flats & HMOs and plasterboard & masonry.
Across London, offices, shops, hotels, student halls and blocks of flats all need sealant work from time to time, whether that is washroom resealing or fire-rated sealant around service openings. Where a building in Dartmouth Park needs to stay open, work can be planned outside normal hours.
Big or small, you get the same one-year guarantee in Dartmouth Park and across Greater London.
- Location
- Dartmouth Park (NW5, N19, N7)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Why it’s worth doing now in Dartmouth Park
Squirting in whichever sealant is nearest does not make a fire seal. Fire-rated products are tested in set gap sizes, depths and substrates, which is why we match the product and the method to each gap. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
Why choose Mr Mastic in Dartmouth Park
- 20+ years of sealant experience
- We’re fully insured
- 4.9 on Google from 180+ five-star reviews
- Trusted Arbo and Everbuild sealants
See our cost guide and customer reviews.
How the visit works
Before we leave, we go over the finished joints with you and tell you how long to leave it. The work normally takes a few hours for a handful of gaps, and longer for a whole building, depending on the size of the job. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- Access to each area is agreed so the work can run in order.
- We take out any damaged or unsuitable sealant.
- Gaps are cleaned of dust and loose material.
- 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
- Where the joints are inside, avoid wetting them before we arrive
- Clear items away from the joints we’re working on
- Keep pets and children clear of the area while we work
How to get a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we’ll explain what’s involved before giving you a price.
Related advice
FAQs for Dartmouth Park
Is parking an issue for fire rated sealant in Dartmouth Park?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Do you take on hotel work around Dartmouth Park?
Yes, hospitality work, including hotels, is part of what we do. Jobs can be programmed room by room, with out-of-hours working possible to arrange.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Can I choose the sealant colour?
Most of the time, yes. We’ll explain which colours are available and agree one before work begins.
Do you hold any approvals?
Yes. Mr Mastic is an ARBOMaster approved applicator and we are fully insured too.
Is intumescent sealant the same as fire-rated sealant?
Intumescent describes a material that swells in heat. Intumescent sealants are a type of fire-rated sealant and which one is used depends on the job.
Will we have a record of what was sealed?
Yes. We note each location and the product that went in, so you have it on file.
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 will talk you through it.
Landlords, agents and businesses in Dartmouth Park
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements and we’ll quote.
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
Different surfaces, different methods
Service penetrations
Service penetrations are where new gaps often appear. We clean out what’s there and reseal to the right depth with backing where the detail needs it.
Plasterboard walls
Holes in plasterboard are often cut roughly for services. Where a hole is bigger than the sealant’s tested range, it needs another approach.
What sealant work can’t fix
New sealant can’t fix everything, and we’d rather say so up front. Sealant will not put right:
- Doors that aren’t fire doors in the first place
- Large holes that need a different fire-stopping system
- Issuing a fire rating or certificate for a building
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think.
Surfaces we seal
- Linear gaps
- Flats & HMOs
- Pipe & cable gaps
- Plasterboard & masonry
- Service penetrations
- Door frames
Keeping the joints in good condition
How long the joints last depends on use and care. Here’s what we suggest:
- Don’t paint over fire sealant until it has cured
- Keep the record of products and locations with your fire safety documents
- Check risers, ceiling voids and cupboards during building checks
- Flag any open gap you spot round a pipe or cable
Do not add foam, filler or ordinary sealant over a fire seal. Repairs should use a matching fire-rated product. We can tell you which product we used.
Any job that breaks through a wall or ceiling should include resealing. Catching it then saves a separate visit later.
What we’re called out for in Dartmouth Park
Gaps also open up as buildings move: cracked or debonded sealant leaves an open route through the wall. Knocks, maintenance and building work damage it further.
The most common problems we see are:
- Gaps where walls meet ceilings or slabs
- Gaps filled with a product that is not fire-rated
- New service routes left unsealed after building work
- Unsealed gaps where pipes and cables go through a wall
For landlords with property near Gospel Oak station, fire-rated sealant around pipes and cables through walls and floors needs making good whenever new services go through.
What to look for in a quote
- How much experience the applicator has
- What preparation is included
- What happens if they find a problem under the old sealant
- What product goes in the joint
Places near Dartmouth Park
What else we do in Dartmouth Park
Workplaces and buildings in Dartmouth Park
There are hotels and other places to stay in and around Dartmouth Park. For hotels, a room-by-room programme keeps most rooms in use while the work goes on. 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 work to the specification you’re given, installing the product to its tested details.
Dartmouth Park is in London, so parking needs planning: let us know about parking bays, permits or a driveway. Managing a site like Acland Burghley School? Then gaps opened by contractors for new cabling are a common finding in schools and offices.
Dartmouth Park is about 2 miles east of Hampstead, in Greater London. For fire rated sealant in and around Dartmouth Park, please phone 0345 464 0079 or send us an email for a quick quote. We cover Greater London from our Crawley base, Dartmouth Park included. Our Greater London coverage runs to 764 places, and Dartmouth Park is one of them.
We cover every part of NW5, N19 and N7 for fire rated sealant and the streets around it. That includes homes and businesses on Hugo Road, Ward Road and Anson Road and the roads around them. We also cover the places around Dartmouth Park: Lissenden Gardens (1 mile south-west), Tufnell Park (1 mile east), Gospel Oak (1 mile south-west), Upper Holloway (1 mile north-east) and Highgate (1 mile north). Further out, we also cover London (5 miles south-east), City of Westminster (3 miles south), Marylebone (3 miles south), Kensington (5 miles south-west), St Pancras (3 miles south-east) and Shoreditch (4 miles south-east).
Landmarks near Dartmouth Park
In Dartmouth Park, that means homes and buildings near The Dartmouth Arms, Whittington Park and Brookfield Primary School, among other places. Also close by are Asanté Academy of Chinese Medicine (1.4 miles north) and Vaughan Williams Memorial Library (1.5 miles south). The nearest railway station is Gospel Oak station, about 0.5 miles south-west. Nearby you’ll also find O2 Centre (1.8 miles south-west) and Isokon Gallery (1 mile south-west). Not far away are Belsize Wood and Dartmouth Park Hill.