Masonry Mortar For Porous Blocks

For building exterior and interior walls and partitions using porous blocks





Maximum particle size0.63 mm
Recommended layer thickness2 to 5 mm
Mortar mix effective life *at least 2 hours
Compressive strength after 28 days *at least 7.5 MPa
Freeze-thaw durabilityat least 50 cycles
Thermal conductivity0.8 W/(m•K)
standard value
Operating temperature-30°С to +70°С
Dry mix consumption per 1 m3 of masonryabout 25 kg

* Under normal conditions – temperature +20°С, relative air humidity 60%.

In the case of working under conditions other than normal the values may deviate from those given in the table.


building exterior and interior walls and partitions using porous blocks (autoclaved aerated concrete, foam concrete, shell limestone, etc.). Siltek M-2 mortar is efficient for thin-layer local leveling, filling seams and joints between the blocks and all kinds of mineral (except gypsum) surfaces. Siltek М-2 mortar with "Winter" label on the bag may be used at air temperature not lower than -5 °C.


high quality cement PC I-500, graded aggregates, modifying additives.

Surface preparation (according to DSTU-N B А.3.1-23:2013, DSTU-N B V.2.6-212:2016):

block surface should be strong, with no considerable damage, and free from dust, dirt, oil and any substances that reduce adhesion.

Preparation of mortar mix:

pour water in a clean working container at the rate of 4.25 - 4.75 l of water per 1 bag of Siltek M-2 (0.17 - 0.19 l per 1 kg of dry mix);

gradually add dry mix and stir with a low-speed mixer to obtain homogeneous, pasty mass without lumps;

leave the mixture for about 3 to 5 minutes, then stir again.

Application process:

using a trowel or steel putty knife apply mortar mix onto the contact surface and level with notched trowel with notch size of 6x6 mm or 8x8 mm (thickness of the layer depends on the quality of blocks);

the time from applying mortar mix onto the surface till laying the blocks shall not exceed 10 minutes;

when laying blocks, do not press them strongly to the surface (they may be adjusted within 3 minutes, if necessary)

period of commencement of mortar mix hardening depends on the type of blocks and atmospheric conditions;

wash tools thoroughly upon completion or stoppage of work;


paper bags with inner polyethylene layer. Net weight 25 kg.


in undamaged packaging, on pallets, in dry place at temperatures not above +40 °C and air humidity not above 75 %. Guaranteed shelf life is 12 months from manufacturing date indicated on the package.

Safety Rules:

keep out of the reach of children;

while working protect the respiratory system;

avoid contact with skin;

in case of contact with eyes rinse with clean water and, if necessary, seek medical advice.


it is recommended to perform all work at the surface and air temperature of + 5 °C to +30 °C and relative humidity of 55-65 %;

do not use in gypsum block masonry;

in the hot season it is recommended to moisten the block surface before masonry;

when temperature lowers to -5 °C, for urgent completion of work it is  recommended to add an antifreeze admixture "calcium formate" (according to application instructions) to the water when preparing Siltek M-2 mix without "Winter" label. The surface of the block before masonry should be free of ice deposits (additional heating possible). It is recommended to prepare mortar mix in plastic container using heated water (up to +35 °C).

Manufacturer Warranty:

the manufacturer guarantees conformance of Siltek M-2 Masonry Mortar to stated specifications only subject to compliance with masonry technique, as well as compliance with the rules of transportation and storage;

the manufacturer cannot be held responsible for the use of material for the purposes and under conditions not covered by these instructions. These instructions are for information purposes only and do not substitute professional training of the worker. When using material under conditions not stated in this technical specifications, it is necessary to conduct independently additional tests or consult the manufacturer.