Hampshire · England
Fire Rated Sealant in Knowle
Fire-stopping gaps in Knowle need attention? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Door frames with gaps between frame and wall
- Open holes round services passing through fire walls
- New service routes left unsealed after building work
Fire rated sealant in Knowle, done properly
In flats, HMOs, offices and schools, fire stopping is often disturbed by later work. One new cable or pipe can leave a gap that nobody goes back to seal. We seal them with a product tested for that kind of gap. If you’re dealing with fire stopping disturbed by later work and fire seals that have cracked with movement, we can help.
For holiday lets, converted business premises or a community building near Knowle, washroom and kitchen sealant and any fire-rated joints need the same attention as anywhere.
We guarantee the work for a year. If something isn’t right with it in that time, tell us and we’ll put it right.
- Place
- Knowle (PO17)
- Region
- Hampshire
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Leave it or put it right?
For some gaps, sealant isn’t the right answer and another system is needed. Big openings, bundles of cables and plastic pipes may need batts, collars or wraps instead. We’ll say so if a gap needs something other than sealant. Where a wall is exposed, as many are in small places like Knowle, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
What it costs depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before work begins, so you know where you stand.
Why choose Mr Mastic in Knowle
- Experience in homes, commercial sites and hotels
- 180+ five-star Google reviews
- A 12-month guarantee on all work
- More than 20 years in sealant work
Take a look at our cost guide or what customers say.
Nearby places to Knowle
What else we do in Knowle
Your questions about fire rated sealant in Knowle
Do you cover smaller places like Knowle?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
I let a flat near Fareham station. Can you help?
Yes, rental work is part of what we do. You can call 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before we start.
Can I add another job to the visit?
Yes. Just list everything you need and you will get one quote.
Will it make a mess?
No. We protect the surfaces around the joints, and we tidy up before we go.
Can I choose the sealant colour?
Yes. Sealants come in white, clear, grey and other colours, and we agree the colour with you before any work starts.
Is standard sealant good enough for a fire gap?
No. Where a fire-rated seal is needed, it has to be a product tested for that use fitted to the maker’s details.
Should I try DIY first?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. If it does not work out, we can redo it.
Can new sealant go over the old?
No. The old sealant always comes out first.
Quotes for fire rated sealant in Knowle
Some jobs are bigger than they look, and some smaller. What affects the quote:
- How easy the joints are to reach
- The old material and how stubborn it is
- Any working-time requirements on site
- Any mould that needs treating
Instead of a standard rate, we look at what your job involves: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
What to tell us for a quote
To help us quote quickly, please include:
- What the problem is, such as mould, gaps, leaks or cracking
- Photos by email, if that is easy
- Whether it has been sealed before
- How many joints, rooms or windows are involved
If you are in Knowle and need fire rated sealant, call 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
What happens on the day
All our tools and materials come with us in the van, so you do not need to buy or prepare anything. After a quick look at the joints together, we protect the area and start. Most jobs take anything from a few hours to several days, depending on how many gaps there are. For a village or hamlet like Knowle, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- 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.
- We apply and tool the sealant to the product’s tested detail.
- We record what was done and flag anything that needs a different system.
How to prepare
- Keep children and pets away from the work area
- Tell us about any previous sealing or DIY attempts
- Let us know if you’ve seen damp or leaks
Get a quote
Need a quote? Please ring 0345 464 0079 or send us an email and tell us about the job. We’ll explain what we’d do and give you a clear quote before we start.
Related advice
Surface by surface
Masonry and concrete
Masonry is dusty and porous, so preparation matters. We brush and vacuum the gap and use backing where the detail needs it before the sealant goes in.
Linear gaps
Linear gaps run along the head of walls, at floor edges and between panels. They’re sealed with a fire-rated sealant over backing where the detail calls for it.
Commercial buildings in Knowle
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 Fareham station change hands often, and any gap left by new services in shared walls should be closed with a fire-rated product. If you look after a building such as Orchard Lea Infant School, service openings in fire-resisting walls need checking after any refurbishment.
Knowle is about 2 miles north of Fareham, in Hampshire. Jobs in Knowle get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Our Hampshire coverage runs to 683 places, Knowle among them. You can also see our page for Portsmouth, roughly 7 miles from Knowle.
All of PO17 is covered for fire rated sealant. Whether your property is on Serotine Close, Boundary Walk and Park Approach or a nearby road, we can help. Nearby, we also carry out fire rated sealant in Funtley (1 mile south), Tapnage (1 mile north-west), Heathfield (2 miles south), Segensworth (2 miles west) and Titchfield Park (2 miles south-west). Within a short drive, we also cover Winchester (13 miles north), Gosport (6 miles south-east), Havant (10 miles east), Eastleigh (9 miles north-west), Horndean (9 miles east) and Totton (13 miles west).
Landmarks near Knowle
In Knowle, that means homes and buildings near The Miners Arms and The Henry Cort Community College, among other places. The closest station to Knowle is Fareham station, roughly 2 miles south. Other landmarks nearby include Portchester Castle (4.9 miles south-east) and Knowle Hospital (less than half a mile north-east). The countryside around Knowle includes Portsdown Hill and Swanwick Lakes.
Honest limits
New sealant cannot fix everything, and we’ll tell you before any work starts. Sealant will not put right:
- Deciding what fire stopping a building needs
- Fire doors that need new seals, closers or hardware
- Issuing a fire rating or certificate for a building
If in doubt, phone 0345 464 0079 or email us and we will say what we think before you book.
What we seal
- Door frames
- Linear gaps
- Pipe & cable gaps
- Service penetrations
- Flats & HMOs
- Plasterboard & masonry
Work for landlords, hotels and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
We work for landlords and letting agents as well as householders. Resealing between tenancies keeps a property looking cared for before the next move-in.
Signs you need fire rated sealant in Knowle
Door frames are a common weak spot. The architrave hides the gap between frame and wall, so it can be left open when a door is replaced.
Any of these means the joints need attention:
- Fire seals that have cracked with movement
- Open joints along the top of partitions
- Sealant items on a fire risk assessment action list
- Damaged fire sealant left by other trades
If you look after a church, hall or community building such as Church of St Francis, older buildings that have had new heating or wiring often have service gaps worth checking.
What to look for in a quote
- Is VAT in the price?
- How the joint is cleaned and prepared
- Whether the sealant suits the joint
- How long to leave it before use