Bemix F4 FF


Bemix F4 FF is a thixotropic, expanding, pumpable jointing compound. It is used for sealing and jointing concrete elements and granite blocks. With its thixotropic consistency, it is the first choice for vertical joints. Easily applied with pumping equipment or by hand. Also suitable for horizontal joints and other types of cast joints. Expansion down to –10 °C without heating.

Product data

Article Number:




25 kg

1000 kg

Product category

Expanding mortar

Expanding mortar


Jointing, Application in sub-zero temperatures, Pumpable Jointing, Application in sub-zero temperatures, Pumpable

Processable minutes


Compression strength

40 40

Layer thickness in mm

5-50 5-50

Consumption kg/m2/mm

2 2

Water quantity litres/25 kg



1 kg dry mortar = finished concrete in litres

0,5 0,5


Yes Yes


Is done mechanically for approximately 5 minutes in a slow-action mixer, such as a flat or free-fall mixer. Smaller quantities can be mixed with a mixer attachment. The concrete mix should have a temperature of approximately 20°C. Compensate cold dry material with warm water and vice versa.

Application advice:
The surfaces of the joins should be clean and free of dust, damaged concrete, grease or other contaminants that could impair adhesion. Pre-water for at least 24 hours. Remove surface water immediately before casting. Rough surfaces give better adhesion. The concrete is applied manually and carefully packed. The concrete can also be pumped with a purpose-designed concrete pump. Ensure that joints and underpourings are always completely filled so as to avoid cavities.

After treatment:
Semi-hardened material can be adjusted with a finishing trowel. Free and undamaged surfaces should be treated immediately after casting with a thin, light misting of water that cannot mechanically damage the material. As soon as it is hard, water for a long period and cover with plastic. Keep the concrete damp for at least a week after application and try to keep an even temperature of 15˚C while it is curing. Watering should not be done if applying in sub-zero temperatures.