Bemix F4


Bemix F4 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.

Product data

Article Number:




25 kg á 40 bags/palette

1000 kg

Product category

Expanding mortar

Expanding mortar


Jointing, Pumpable Jointing, Pumpable

Processable minutes


Compression strength

40 MPa 40 MPa

Layer thickness

5-50 mm

5-50 mm


2 kg/m2/mm 2 kg/m2/mm

Water quantity per 25 kg

4.0 litres

4.0 litres

1 kg dry mortar = finished concrete in litres



Yes Yes



The concrete substrate must be clean and free of dust, damaged concrete, grease or other contaminants that may impair adhesion. Substrate with a roughened and raw surface with closely spaced irregularities provide better adhesion. Clean the substrate carefully and if possible pre-water 24 hours before casting. Remove free water just before casting.


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. In sub-zero temperatures use Bemix F4 FF.

Application advice:

The mortar is applied manually and carefully packed or 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 trowel. Free and unprotected surfaces are protected immediately after casting so that shrinkage and dehydration cracks do not occur. After casting, the surface can be moisture-cured with a thin, light mist of water, but that cannot mechanically damage the mortar. At air temperatures above 5°C, curing may take place with remaining form, covering or supply of water and may last the entire first week. As soon as the surface hardens, it can be watered and covered.