Greater London · England
Fire-rated sealant in Coldharbour, Greater London
Specialist fire rated sealant for Coldharbour: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Gaps where walls meet ceilings or slabs
- Open holes round services passing through fire walls
- New service routes left unsealed after building work
When something else is needed
Sealant is not the answer to every problem, and we’d rather say so up front. It will not solve:
- Fire risk assessments, which need a qualified assessor
- Construction that does not provide fire resistance on its own
- Sign-off of the building, which sits with building control or your assessor
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we’ll tell you honestly before you book.
Where we work in Coldharbour
- Linear gaps
- Pipe & cable gaps
- Plasterboard & masonry
- Door frames
- Service penetrations
- Flats & HMOs
Fire rated sealant in Coldharbour, done properly
In flats, HMOs, offices and schools, fire stopping is often disturbed by later work. A new cable run or a replaced pipe can leave an open hole behind. Those are the gaps we close, using a tested fire-rated product. We work on linear gaps, flats & HMOs and door frames, and the jobs we see most are damaged fire sealant left by other trades and ordinary sealant used where a fire-rated product was needed.
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. Out-of-hours working can be arranged where a building in Coldharbour can’t close.
There’s a 12-month guarantee on every job, large or small.
- Location
- Coldharbour (SE9, BR7)
- Region
- Greater London
- Cover
- One year on every job
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Fire rated sealant around Coldharbour
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. Many London buildings have tight access and loading restrictions, so out-of-hours working can be arranged where needed.
Coldharbour is in London, so parking needs planning: let us know about parking bays, permits or a driveway. If you look after a church, hall or community building such as St Alban, older buildings that have had new heating or wiring often have service gaps worth checking.
Coldharbour is about 4 miles north-west of Orpington, in Greater London. We carry out fire rated sealant for homes and businesses in Coldharbour and the surrounding area. Coldharbour is one of 764 towns and villages in Greater London where we work for fire rated sealant. Our London page covers work nearby, about 8 miles away.
Every address in SE9 and BR7 is covered for fire rated sealant, from the main roads to the quietest streets. If you need fire rated sealant at a property on Green Lane, Horley Road and Dorset Road or a nearby road, our applicators can take on the job. Neighbouring places we cover for fire rated sealant include Mottingham (1 mile west), Chinbrook (1 mile west), New Eltham (1 mile north-east), Eltham (1 mile north) and Middle Park (1 mile north-west). Larger places within reach include London (8 miles north-west), City of Westminster (11 miles north-west), Marylebone (10 miles north-west), Kensington (12 miles north-west), St Pancras (10 miles north-west) and Shoreditch (9 miles north-west).
Around Coldharbour
Locally, jobs take us to homes and businesses close to Elmstead Wood and St Thomas More Catholic Comprehensive School, among other places. For rail, the closest station is Mottingham station, about 0.6 miles north of the centre. Other landmarks nearby include The Glades (2.4 miles south-west) and Metropolitan Police Museum (2.2 miles east). Green spaces nearby include The Tarn and Summer Hill.
Towns and villages near Coldharbour
What else we do in Coldharbour
Landlords, agents and businesses in Coldharbour
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
How the job changes by surface
Masonry and concrete
For masonry and concrete, we use a product tested in that substrate. We clean out dust and debris before sealing so the sealant bonds.
Flats and HMOs
In occupied buildings, we plan the order of work with you. We agree access to each flat and the common parts before we start so residents know what to expect.
Common questions in Coldharbour
Can you help a landlord with a rental near Mottingham station?
Yes. We work for landlords and letting agents as well as homeowners, and several properties can go on one quote. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Is parking a problem for a job in Coldharbour?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Do you work in Coldharbour?
We do. Coldharbour is part of the area we cover.
Can you match the sealant colour?
In most cases you can choose. We’ll explain which colours are available.
Do the sealants smell?
It depends on the product. Some products have a noticeable smell, others very little, and any smell fades as they cure.
How much does fire rated sealant cost in Coldharbour?
Size, access and the old material all affect the cost. Ask us for a 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.
Can you tell me which gaps need fire stopping?
No, we do not assess buildings. Once you have a specification or action list from your assessor or designer, we can quote for the fire-rated sealant items.
Signs you need fire rated sealant in Coldharbour
Over time, buildings change layout and use. A house turned into flats or an HMO, or an office split into smaller units, brings new walls, new service routes and new gaps.
If you can see any of these, it’s time to have the joints looked at:
- Standard silicone or caulk in a fire-stopping gap
- Seals cut through by electricians, plumbers or data installers
- Cracked or shrunken fire-rated sealant
- Open holes round services passing through fire walls
For site and facilities teams at buildings such as Mottingham Primary School, service openings in fire-resisting walls need checking after any refurbishment.
What your quote should include
- Which sealant they’ll use, and why
- How long to leave it before use
- Who turns up on the day
- What happens if they find a problem under the old sealant
Why deal with it now?
Leaving a gap until a refurbishment comes round can mean years with it open. On its own, sealing it now is a small job that does not depend on other work. Damp from a failed joint spreads quietly in older London brickwork and timber, and once it shows in Coldharbour, the repair is bigger than a sealant job.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Why choose Mr Mastic in Coldharbour
- Every job guaranteed for a year
- ARBOMaster approved applicator
- More than 20 years in sealant work
- Tidy, careful work
Take a look at what affects the cost or our reviews.
What we do, step by step
Most of a good job is in the preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it generally takes a few hours for a handful of gaps, and longer for a whole building. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Coldharbour. A visitor permit or a nearby bay makes the visit run more smoothly.
- Access to each area is agreed so the work can run in order.
- We take out any damaged or unsuitable sealant.
- 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.
Getting ready for the visit
- Keep pets and children clear of the area while we work
- Move anything stored near the joints
- Tell us about any previous sealing or DIY attempts
Ask for a quote
We quote each job on its own. Just ring 0345 464 0079 or drop us an email with the details, and photos are welcome.
Read more
Keeping the joints in good condition
After the cure time, these simple habits help:
- Look in service cupboards and ceiling voids from time to time
- Do not fill fire-stopping gaps with ordinary foam or silicone
- Don’t paint over fire sealant until it has cured
- Include fire stopping when you schedule refits
Leave the sealant to cure fully before painting near it. Some fire-rated sealants can be painted and some can’t, so ask us which we used.
A flagged gap shouldn’t wait for the next assessment. Get it sealed and recorded so the item can be closed.