HENSOTHERM 461 KS R15-R90 25KG
What is this product?
Water-based fire protection for structural steel
HENSOTHERM 461 KS is a water-based, single-component intumescent coating for structural steel in indoor use. It is maintenance-free and approved in accordance with BS 476, Certifire No. CF 5678.
Fire resistance
- Open sections, beams: R15 to R60
- Open sections, columns: R15 to R90
- Hollow sections: R15 to R60
Where it is used
- Structural steel columns, beams, girders, I- and H-sections
- Open sections up to Hp/A 375 m⁻¹, hollow sections up to Hp/A 325 m⁻¹
- Approved for galvanised sections
- Indoor use only
Product characteristics
- Free of halogens, APEO, borates, plasticisers and silicones
- Non-VOC according to ISO 11890-2 (VOC below 1 g/l), LEED v4 confirmed
- Colour: white
- Suitable for shop application thanks to fast drying
- Top coats available in RAL shades or to an individual colour sample
Technical data
- First coat on primed steel: 500 g/m² (approx. 250 µm dry)
- Further coats: up to 1,000 g/m² (approx. 500 µm dry) each
- At least 24 hours between coats at approx. +20°C and 65% relative humidity, after a positive fingernail test
- Airless spray: 200 to 250 bar, nozzle 0.017 to 0.025 inch, output above 4 l/min, thin with max. 3% water
- Brush or roller: lambskin or foam roller, long-bristled Chinex brush
- Apply preferably above +10°C and below 80% relative humidity, steel at least 5°C above dew point
- For application by trained personnel
- Supplied in 25 kg plastic pails
Documents
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R15 to R90 to BS 476, Certifire CF 5678
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Water-based, non-VOC
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Free of halogens, APEO, borates, plasticisers and silicones
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Approved for galvanised sections
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Suitable for shop application
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LEED v4 confirmed
Specifications & Documents
Full technical data and downloadable certification for compliance records.
| Finish | White. Top coats in RAL shades or to an individual colour sample. |
| Use | Indoor |
| Application Method | Airless spray (200 to 250 bar, nozzle 0.017 to 0.025 inch), lambskin or foam roller, or brush |
| Fire Classification | R15 to R60 beams, R15 to R90 columns, R15 to R60 hollow sections |
| British Standard | BS 476 (Certifire CF 5678) |
| VOC Content | Below 1 g/l, non-VOC according to ISO 11890-2 |
| Shelf Life | Minimum 12 months unopened at +20°C from date of manufacture |
How to Apply
Simple application with standard tools — no specialist equipment required.
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1Prime steel before HENSOTHERM 461 KSBlast-cleaned steel (Sa 2.5): prime with HENSOGRUND AQ, HENSOGRUND 1966 E+ or HENSOGRUND 2K EP. Manually cleaned steel (PSt 2): HENSOGRUND 1K AK. Galvanised steel: HENSOGRUND 2K.
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2Check conditions for HENSOTHERM 461 KSApply and dry preferably above +10°C and below 80% relative humidity. Steel at least 5°C above dew point and not above +35°C. Application by trained personnel only.
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3Stir HENSOTHERM 461 KSStir thoroughly at low speed before use.
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4Apply HENSOTHERM 461 KSAirless spray at 200 to 250 bar, nozzle 0.017 to 0.025 inch, output above 4 l/min, filters removed, thinned with max. 3% water. Or lambskin or foam roller, or long-bristled Chinex brush. First coat 500 g/m², further coats up to 1,000 g/m².
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5Allow HENSOTHERM 461 KS to dry between coatsAt least 24 hours at approx. +20°C and 65% relative humidity. Each coat must pass the fingernail test before the next.
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6Top coat HENSOTHERM 461 KSWhere required, apply HENSOTOP WB, SB or 2K PU only when fully dry: at least 24 hours and after a positive fingernail test.
Coverage Guide
Frequently Asked Questions
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HENSOTHERM 461 KS is a water-based intumescent coating for structural steel columns, beams, girders, I- and H-sections and hollow sections, for indoor use.
R15 to R60 for open section beams, R15 to R90 for open section columns, and R15 to R60 for hollow sections.
It is approved in accordance with BS 476, Certifire No. CF 5678.
Yes. It is approved for galvanised sections, primed with HENSOGRUND 2K after the galvanising has been fully degassed.
First coat on primed steel 500 g/m² (approx. 250 µm dry). Further coats up to 1,000 g/m² (approx. 500 µm dry) each.
At least 24 hours at approx. +20°C and 65% relative humidity, and each coat must pass the fingernail test.
A top coat is mandatory where the surface will be cleaned. Without a top coat, use only in dry indoor conditions without condensation. Compatible top coats are HENSOTOP WB, HENSOTOP SB and HENSOTOP 2K PU.
No. It is for indoor use only.
What Our Customers Say
Verified reviews collected via eKomi — independently moderated and genuine.
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★★★★★
Gave them a ring to ask for some advice, was pointed to exactly what I needed and how much. Arrived promptly and has performed perfectly.
Verified purchase · 2 weeks ago -
★★★★★
Very quick response to query and fast delivery. Easy to use product with good instructions. Great company. Will use again.
Verified purchase · 1 month ago -
★★★★★
Excellent product with swift delivery. Easy to top up fire retardancy after the deck was cleaned. Looks completely untreated which was exactly what we wanted.
Verified purchase · 1 month ago