masonry mortar for cellular concrete

P1  na ściany P1 na ściany
P3  do wewnątrz P3 do wewnątrz
P4  na zewnątrz P4 na zewnątrz
W1  mrozoodporność W1 mrozoodporność
W2  wodoodporność W2 wodoodporność
N2  paca stalowa zębata N2 paca stalowa zębata

Product description

Recommended for construction of walls of cellular concrete (aerated concrete).
Prevents creation of thermal bridging – provides uniform thermal insulation parameters for the whole partition.

Main properties

  • for walls of cellular concrete (aerated concrete)
  • for blocks, bricks and hollow bricks
  • finishing the surface
  • prevents creation of thermal bridging
  • compressive strength – M5 category

Main parameters

  • compressive strength: ≥ 5.0 N/mm²
  • consumption: 8 kg/1 m² for wall 24 cm thick
  • layer thickness: 2 - 10 mm


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Recommended for construction of walls of cellular concrete (aerated concrete).

Prevents creation of thermal bridging – provides uniform thermal insulation parameters for the whole partition.

Used for thin joint brickworks – recommended layer thickness is between 2 and 10 mm (optimum thickness: 2 – 3 mm).

Used for floating and leveling the surface – recommended layer thickness for this application: 2 – 5 mm.

Types of joined elements – cellular concrete, aerated concrete, as well as bricks, hollow bricks and other similar ceramic, lime-sand and concrete elements.


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Compressive strength – M5 category.

Easy and comfortable to use – characterized by very good workability, plasticity and high adhesion.

High output – possibility to control the layer thickness by application with a notched trowel or dosage unit reduces the consumption of the mortar and speeds up the works.

The mortar can be supplemented with so-called anti-frost additives allowing to carry out works at lowered temperatures, i.e. below +5°C – the new temperature range of mortar application, the way of its preparation (especially the adjustment of the amount of water added), principles of carrying out works and the mortar setting conditions must be accepted according to the guidelines of the manufacturer of the additive. The amount of the anti-frost agent depends on the content of cement in the mortar – the proportion of cement to fillers in ATLAS KB-15 is at 1:2. Note. The manufacturer of the mortar is in no way responsible for the effects and the quality of the anti-frost agents used.


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ATLAS KB-15 is manufactured in the form of dry mix of cement binder, aggregate and modifying agents.

Bulk density (of dry mix)
ca. 1.4 kg/dm³
Wet density (after mixing)
ca. 1.65 kg/dm³
Dry density (after setting)
ca. 1.5 kg/dm³
Mixing proportions
(water/dry mix)
0.21 ÷ 0.24 l/1 kg
5.25 ÷ 6.00 l/25 kg
Min./max. layer thickness
2 mm / 10 mm
Mortar preparation temperature,
substrate and ambient temperature
during work
from +5°C to +30°C
Pot life
ca. 4 hours


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The product conforms to EN 998-2 standard. EC Declaration of Performance No. 008/CPR.

CE 1488
PN-EN 998-2:2012
(EN 998-2:2010)
Factory-made masonry mortar,
according to design,
for thin joints (T)
for indoor and outdoor use,

in elements subject to structural

requirements designed for reinforced

and un-reinforced walls, for masonry walls,

posts and partition walls
Compressive strength
≥ 5.0 N/mm²
Joint resistance – initial shear
strength (tabular value)
≥ 0.30 N/mm²
Chloride content
≤ 0.1% Cl
Reaction to fire - class
Water absorption
0.05 kg/m² ∙min0,5

Water vapour permeability coefficient μ

Tabular value
(EN 1745:2002 tab. A.12)
Thermal conductivity coefficient
(average tabular value P=50%)
0.83 W/mK (λ10, dry)
(EN 1745:2002 tab. A.12)

Durability. Compressive strength decrease

after 25 freeze-thaw cycles
≤ 10 %
Durability. Mass decrement
after 25 freeze-thaw cycles
≤ 3 %
Adjustment time
≥ 10 minutes
Aggregate grain size
≤ 1.6 mm
Release/content of hazardous
See: Material Safety Data Sheet

The product has been given the Hygiene Certificate by the National Institute of Hygiene, the ITB Certificate of Conformity No. 1488-CPD-0013/Z and the Radiation Hygiene Certificate.


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Preparation of cellular concrete elements

Masonry works. The surfaces of joined elements must be cleaned from dust and chippings. In order to obtain a thin joint of even thickness along the whole layer, it is recommended to sand and dust the surface of previously laid elements.

Surface floating. In case of leveling or finishing the surface, it must be dry, stable, even and sound, i.e. strong enough, free from layers that may weaken the adhesion of the mortar, especially from dust, dirt, lime, oil, grease, wax, remains of oil and emulsion paint. Reduce excessive absorptivity of the substrate before finishing, using ATLAS UNI-GRUNT priming emulsion.

Weather conditions

Prior to works commencement, account both for the weather conditions at which the works will be carried out and conditions at which the setting and drying process will take place.

Mortar preparation

Pour the mortar from the bag into a clean container with the suitable amount of water (see Technical Data for proportions) and mix using a drill with a mixer (or in cement mixer) until homogenous. Leave the mix adhesive to rest for 5 minutes and then remix. The mortar should be used up within ca. 4 hours.

Mortar application
The works should be carried out in accordance with the masonry work technology for walls of cellular concrete blocks. Use ATLAS MASONRY MORTAR to apply the first layer. Apply ATLAS KB-15 mortar evenly with a notched trowel on a horizontal plane of the previously executed layer. The mortar must be also applied to vertical contact surfaces of adjacent blocks unless the technology provides otherwise. Each new placed element must be pressed down and fixed in the desired position with a rubber mallet.


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Masonry works

wall thickness
Joint thickness
2 mm
From a 25 kg bag
12 cm
ca. 4 kg/m²
ca. 6.2 m²
18 cm
ca. 6 kg/m²
ca. 4.2 m²
24 cm
ca. 8 kg/m²
ca. 3.1 m²
30 cm
ca. 10 kg/m²
ca. 2.5 m²
36 cm
ca. 12 kg/m²
ca. 2.1 m²
Surface floating
The average consumption is around 1.6 kg for 1 m² of surface for each 1 mm of layer thickness.


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• Do not apply the mortar over a large surface at once, because it retains it binding properties for around 10 ÷ 30 minutes (depending on the substrate properties and ambient conditions). In order to check if joining blocks is still possible, press a hand to the applied mortar. If the mortar sticks to fingers, then you can fix the next element. If the fingers remain clean, the mortar must be removed and the new layer applied.

• Adjust the ratio of added water experimentally, following the desired consistency of the mortar, type of substrate and weather conditions. Inappropriate amount of water for mix preparation results in deterioration of strength parameters of the mortar.

• Tools must be cleaned with clean water directly after use. Difficult to remove residues of the set mortar can be removed with the ATLAS SZOP agent.

• Irritant - contains cement. Irritating to respiratory system and skin. Risk of serious damage to eyes. May cause sensitisation by skin contact. Due to its form - powder, the product may cause mechanical irritation of eyes and respiratory system. Keep out of reach of children. Do not breathe dust. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. Wear suitable protective clothing, gloves and eye/face protection. If swallowed, seek medical advice immediately and show the container or label. Follow the instructions in the Material Safety Data Sheet.

• Content of soluble chromium (VI) in ready-to-use mix - ≤ 0.0002%.


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The mortar must be transported and stored in tightly sealed bags, in dry conditions (most preferably on pallets). Protect against humidity. Shelf life in conditions as specified is 12 months from the production date shown on the packaging.


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Paper bags: 25 kg
Pallet: 1050 kg in 25 kg bags


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The above information constitutes basic guidelines for the application of the product and does not release the user from the obligation of carrying out works according to engineering principles and OHS regulations.

At the time of publication of this product data sheet all previous ones become void.
Date of update: 2014-06-04