Greater London · England
Fire-rated sealant in Clapham, Greater London
Fire rated sealant for Clapham, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- New service routes left unsealed after building work
- Ordinary sealant used where a fire-rated product was needed
- Open gaps behind door architraves
How we handle fire rated sealant in Clapham
Filling a fire-stopping gap with standard silicone or caulk doesn’t make it fire-rated. We cut out the wrong material and the gap is resealed with a product tested for that use. If you have unsealed gaps around fire door frames and gaps left after a refit or conversion, we can put it right.
Commercial work in London comes with its own logistics: loading restrictions, building rules and tight access. Timings and access are agreed with the building before work starts in Clapham.
The work is covered for a year after we finish. If anything is not right with it, phone 0345 464 0079 or email us.
- Where
- Clapham (SW4, SW8, SW9)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Surface by surface
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, flat by flat if needed.
Plasterboard walls
Many fire-resisting walls in flats, offices and conversions are plasterboard. We use a product tested in that kind of wall for the gap we’re sealing.
Quotes for fire rated sealant in Clapham
Your quote is based on your job. We look at:
- Access and height
- The size of the job
- Working hours on commercial sites
- Which sealant suits the joint
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether we need extra access for height. We take all of that into account in your quote.
What we need to know
When you call or email, these details help:
- How we’d reach the joints
- What’s wrong with the joints now
- Where the job is, and your postcode
- Roughly how big the job is
Asking for a quote is easy: let us know the job and the location. A few pictures by email make the job easier to understand, and we will take it from there.
Nearby places to Clapham
Also in Clapham
How it works
Our applicators work methodically: protect, prepare, seal, tidy. Typically it takes from a few hours to a few days, depending on the number of gaps and the access. In Clapham, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We go through the gaps on your list or survey and check each one’s size and substrate.
- We remove any old or unsuitable filler and clean the gap.
- We put in whatever backing or fill the product detail specifies.
- The sealant goes in to the depth its detail sets, then it’s tooled off.
- We record the locations and products used for your records.
Before we arrive
- Mention any sign-in or site rules at work premises
- Tell us about any previous sealing or DIY attempts
- Tell us if parking is tricky
Get a quote
We quote each job on its own, so the first step is telling us about yours. Simply ring 0345 464 0079 or email us and describe the job, and photos are welcome.
Related advice
Clapham: your questions answered
Can you help a landlord with a rental near Clapham High Street station?
Yes. We work for letting agents and landlords as well as householders, and several properties can go on one quote. You can call 0345 464 0079 or email us with the details for a clear quote.
Is parking an issue for fire rated sealant in Clapham?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Will there be a smell?
Possibly a little. Any smell clears as the sealant cures.
What should I tell you?
Just the basics: where it is, what you’ve noticed and how we reach it. After that, simply ring 0345 464 0079 or drop us an email.
Do you provide details of the products used?
Yes. We note each location and the product that went in, so you have it on file.
Can ordinary silicone be used in a fire-stopping gap?
No. Where a fire-rated seal is needed, it has to be a product tested for that use.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint before applying anything new.
Will you assess my building’s fire safety?
No. Your fire risk assessor, designer or building control decides that. Our job is applying the sealant to their specification.
Workplaces and buildings in Clapham
There are hotels and other places to stay in and around Clapham. For hotels, a room-by-room programme keeps most rooms in use while the work goes on. Commercial buildings in London often have strict access rules and limited loading, and out-of-hours working is possible to arrange.
If you look after a church, hall or community building such as St Paul's Church, service openings in its walls need the right fire-rated sealant, as in any building. If you let a flat or house near Clapham High Street station, any gap left by new services in shared walls should be closed with a fire-rated product.
Clapham is about 3 miles north of Streatham, in Greater London. Jobs in Clapham get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. We cover 764 towns and villages across Greater London.
Every address in SW4, SW8 and SW9 is covered for fire rated sealant, from the main roads to the quietest streets. Local streets include Grafton Square, Clapham High Street and Houghton Square, and we cover them all. Being close to the B224 and B303, Clapham is easy for our applicators to reach for fire rated sealant. Close by, we work in Stockwell (1 mile east), Little Portugal (1 mile north-east), Clapham Park (1 mile south), South Lambeth (1 mile north-east) and Brixton (1 mile south-east). Further out, we also cover London (3 miles north-east), City of Westminster (3 miles north), Marylebone (4 miles north), Kensington (4 miles north-west), St Pancras (4 miles north) and Shoreditch (5 miles north-east).
Local landmarks in Clapham
Around Clapham, our work takes us to homes and buildings near Lambeth Academy, Larkhall Park and Trinity Academy, among other places. Clapham has its own railway station: Clapham High Street station. A little further out are Baynard's Castle (3.5 miles north-east) and Harrods (2.6 miles north-west). Not far away are Battersea Park Lake and Knight's Hill.
What we are called out for in Clapham
A lot of fire stopping is out of sight: above ceilings, inside risers and behind panels. Because nobody sees it, gaps go unnoticed until an assessor or surveyor looks.
The most common problems we see are:
- Unsealed gaps where pipes and cables go through a wall
- Sealant items on a fire risk assessment action list
- Gaps left after a refit or conversion
- Ordinary sealant used where a fire-rated product was needed
Schools such as Clapham Manor Primary School are buildings too, and gaps opened by contractors for new cabling are a common finding in schools and offices.
Before you book anyone
- What product goes in the joint
- Who does the work, and how experienced they are
- Whether they’re fully insured
- How hidden problems are handled
Leave it or put it right?
A quick fill with any sealant to hand isn’t fire stopping. Fire-rated products are tested in set gap sizes, depths and substrates, so both the product and the method matter. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Call for a quick quote and we will explain what it covers.
Why choose Mr Mastic in Clapham
- We leave the area clean and tidy
- We’re fully insured
- Anti-fungal sanitary silicone in wet areas
- Domestic, commercial and hotel work
Take a look at how sealant jobs are priced and customer reviews.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Looking after it afterwards
A little care helps the new joints last. We recommend:
- Allow for resealing whenever new services are run
- Include hidden areas like risers in routine checks
- File the fire-stopping record where your assessor can find it
- Never patch a fire seal with standard sealant
Include fire stopping in your regular building checks. Look for cracks, gaps or sealant that has been cut or pulled out and have them put right.
A flagged gap shouldn’t wait for the next assessment. Have it sealed, then keep the record so you can show it was dealt with.