Product description

STEIN TEC® Bedding Mortar BM 04 S is an extreme-quickly binding work dry mortar with application-specific mineral and organic additives. STEIN TEC® Bedding Mortar BM 04 S is available as bag ware (40 kg), as Big Bag (1.000 kg) and/or from 15 t in the silo with mixing device. Due to its quick strength development and its high adhesive tensile strength, it is particularly suited for paved and slabbed surfaces used with up to heaviest loads, if quickest possible loading capacity is required. STEIN TEC® Bedding Mortar BM 04 S features high water permeability and frost resistance. It surpasses in all its properties the normally-binding bedding mortar BM 04. Furthermore, it meets resp. surpasses in its properties the requirements according to the FSGV-Arbeitspapier Nr. 618/2 (working paper for surface pavements with pavings and slabs using bonded construction)..

STEIN TEC® Bedding Mortar BM 04 S is optimally adapted with its material properties, like shrinkage and deformation characteristics, to STEIN TEC® jointing mortars.

The thickness of the bedding when compacted, shall be 4 cm at least, and single-layer, 6 cm maximum. If the bedding thickness is more than 6 cm when compacted, it is necessary to pre-shape in layers under approx. 25 % pre-compaction (required gross density of hardened mortar 1.900 kg/m³, cp. Table “Technical specifications”).


  • quick hardening
  • early loadable
  • high compressive strength
  • high adhesive tensile strength
  • high water-permeability
  • frost-resistant
  • low-shrinkage and low-stress
  • polymer modified
  • very good processability

Important informatione

If concrete blocks, slabs and, in general, elements with smooth and even (e.g sawn) underneaths are used, STEIN TEC® Bond Adhesive Haftfix should be applied additionally.

Paving blocks and slabs must be clean, i.e. free from dust, grease, oil, adhesions and impurities (e.g. cutting or grinding slurry).

For the laying and grouting of paving blocks and slabs in bonded construction method, respective regulations and generally accepted codes of practice do apply, like DIN 18318, ZTV Pflaster-StB (about pavings) and the bulletin M FP as far as applicable to bonded construction method and to the FSGV-Arbeitspapier Nr. 618/2 (working paper for surface pavements with pavings and slabs using bonded construction). Especially important is a sufficiently stable superstructure suited to the expected loads. For traffic areas where heavy traffic is expected, the requirements in terms of design and sustainability should be set for the panel 3 (Construction Classification III according RStO 01) or Load Classification 3.2 according RStO 12.


STEIN TEC® Bedding Mortar BM 04 S shall be mixed either using the horizontal flow-mixer mounted at the silo, or if delivered as bag ware in the positive mixer with clear cold water only (added amount see Technical Bulletin or imprint on bag) in earth-moist texture (snow ball test see under “Information”). On the bedding, the paving blocks resp. slabs shall be finally hammer set in correct height and alignment in projected joint distance. By the piling strike, a compaction of approx. 25 per cent of the mortar bed, professionally prepared, must be achieved underneath the element (required gross density of hardened mortar 1.900 kg/m³, cp. table “Technical specifications”). The mortar bed must be raised up by that slump..

The paved / slabbed surface must be after-treated. For further information see Technical bulletin STEIN TEC® Bedding Mortar BM 04 S.

Set on

Paving block set on the mortar bed.

Hammer setting

Hammer setting of the paving block into the bedding mortar. The bedding mortar must be compacted 25 per cent by the pilling strike.

Set on

Paving block in final position and height after hammer setting.


After-treatment of the bedding mortar by watering and covering of the recently paved surface.

Technical specification

Binding agent base hydraulically binding specialty cements
Minimum processing temperature 5° C, night-frost free
Processing time approx. 1 hour at 20° C
Requirements approx. 20 kg dry mortar / cm / m2
Built-in thickness at least 4 cm, single-layer 6 cm maximum in compacted condition
Compressive strength after 1 day (20° C) * > 15 N/mm2
Compressive strength after 7 days (20° C) * > 30 N/mm2
Compressive strength after 14 days (20° C) * > 35 N/mm2
Compressive strength after 28 days (20° C) * > 35 N/mm2
Adhesive tensile strength1) > 2,0 N/mm2
Gross density of hardened mortar 1.900 kg/m3
E-module < 22.000 N/mm2
Water permeability > kf = 5 x 10-5 m/sec
Frost resistance proven
eduction of sound run-time after CIF test CIF Testing fluid distilled water < 5 %
All values determined on the basis of lab-body blocks in build-in density at 20° C at the specified testing age resp. after 28 days.
1) Determination of adhesive tensile strength on slab base-body according to DAfStb-guideline “Schutz und Instandsetzung von Betonbauteilen, Teil 4 (= Protection and reinstatement work of concrete elements, part 4) with “Haftfix”.
Subject to technical modifications.
Important information
Suitability for storage approx. 6 months in the silo and as bag ware in dry cool rooms.
* The decrease of temperature down to 10° C doubles the needed time for hardening. At the decrease down to 5° C it will be quadrupled.

You can download the Technical bulletin here.