K-FLEX FIRE EX MORTAR is a gypsum based mortar material, used to reinstate the fire resistance performance of wall and floor constructions where they have been provided with apertures for the penetrations of multiple services. When mixed with water, the compounds form a highly thermally insulating fire sealing compound to prevent the spread of fire and smoke through openings in fire rated walls and floors, including openings formed around building service penetrations. K-FLEX FIRE EX MORTAR will also maintain the acoustic design performance in walls and floors. K-FLEX FIRE EX MORTAR expands approx. 1% by hydraulic action during curing ensuring a very tight seal around the service penetrations and the surrounding opening apertures.

K-FLEX FIRE EX MORTAR may be used to offer a penetration seal with cables, cable trays, plastic pipes, composite pipes and metallic pipes with and without insulation
- Up to 4 hours fire resistance (integrity and insulation);
- Can be used in wall and floor penetrations to accommodate a variety of penetrating services;
- Easy to use: can be applied by trowel or poured into place;
- Does not need specialist equipment: simple mixing and application tools can be used and cleaned with water;
- Does not shrink on setting and provides a rigid, gas-tight barrier to smoke, combustion and halogen gasses.

CE Marked 0843–CPR–0251
ETA 15-0261
ETAG 026-2 (2011) according EN 1366-3 Penetration Seals





K-FLEX FIRE EX MORTAR - 20 kg bag 1



Test method

Fire Rating

Up to EI 240 

EN 1633-3        

Tested penetration seal in:

Flexible walls: min. thickness 100 mm;
Rigid walls: min. thickness of 150 mm;
Rigid floors: min. thickness of 150 mm.


Tested service penetration

- PVC-U pipes up to Ø315mm;
- PVC pipe bundles up to Ø32mm;
- PE pipes up to Ø160mm;
- PE pipe bundles up to Ø32mm;
- ABS pipe bundles up to Ø32mm;
- SAN+PVC pipe bundles up to Ø32mm;
- PP pipes up to Ø75mm;
- PP pipe bundles up to Ø32mm;
- Geberit Mepla pipes up to Ø75mm + FEF / MW insulation;
- Alupex pipes up to Ø75mm;
- Alupex pipes up to Ø75mm + FEF / AESW insulation;
- Copper pipes up to Ø54mm + FEF / MW insulation;
- Steel pipes up to Ø165 mm + FEF insulation;
- Steel pipes up to Ø219 mm + MW insulation;
- Single cables up to Ø80mm;
- Cable bundles up to Ø 100mm;
- Steel cable trays and ladders;
- Metal or plastic conduits up to Ø16mm;
- Blank seals up to 2400x1200mm.

*FEF: Flexible Elastomeric Foam
*MW: Mineral Wool
*AESW: Alkaline earth silicate wool


Durability and serviceability

Type Z2: Intended for uses in internal conditions, excluding temperature below 0°C, without exposure to rain or UV.

 EOTA TR 024:2009

Reaction to fire

EN 13501-1       

Storing temperature

5 to 30 °C  


About 900 kg/m3 after full cure  

Thermal conductivity

0.051 W/mK  

Cure rate

Up to 30 days depending on thickness and temp.  

Tack free time

Less than 1 hour depending on the local climate  

Shelf life

6 months  

Acoustic performances

64 dB  

Ecological data

EMICODE emission class EC 1PLUS  
L’ISOLANTE K-FLEX reserves the right to change data and technical requirements without notice.
Contact us for more information.





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