Sand-lime block manufacturer — Trąbki near Szczecin

Load-bearing walls use 18–⁠24 cm blocks — our BT18, BTA18, BTA18+, BT24 and BTA24 in strength class 15 or 20. BT12 suffices for partition walls, and BTA8 for thin partitions and enclosures.

Thin-bed adhesive mortar requires 16 blocks per m²; traditional mortar requires 15.5 blocks per m². We sell full pallets — calculate blocks, pallets and adhesive for your wall using the block calculator.

From R_w 44 dB (BTA8 without plaster) to R_w 60 dB (BTA24 with 15 mm cement-lime plaster). A BT24 wall has R_w 52–⁠54 dB, and BTA24 58–⁠60 dB, depending on plaster. Download the complete acoustic table from the website.

Yes. The products have reaction to fire class A1 and are non-combustible. A 24 cm BT24 or BTA24 wall achieves REI 240 (four hours of load-bearing capacity, integrity and insulation); an 18 cm BT18 or BTA18 wall achieves REI 240 when plastered and REI 120 without plaster. Non-load-bearing 18 and 24 cm walls achieve EI 240. Classes according to PN-EN 1996-1-2 tables.

Yes, using our own transport: a flatbed without unloading (up to 24.5 t) or an HDS crane truck (22, 20 or 12 t). Zone I covers deliveries within 25 km of the factory, zone II up to 75 km and zone III up to 105 km — beyond this, individual quotation. Towns and distances are listed on the sand-lime block delivery page.

Yes, industrial pallets are returnable — the deposit is 30 zł net per pallet. Deliver pallets to the factory in Trąbki within 60 days of purchase; we issue a credit note for returned pallets. Full terms: pallet return rules.

Sand-lime blocks perform well where load-bearing capacity, quiet and fire resistance matter: our blocks have strength class 15–⁠20 N/mm², while aerated concrete typically has 2–⁠4 N/mm². A 24 cm BTA24 wall weighs 416 kg/m² (26.0 kg × 16 units) and has R_w 58 dB, or 60 dB with 15 mm cement-lime plaster; an equally thick class 600 aerated concrete wall weighs about 145 kg/m² — the mass law used for our acoustic table then gives about 45 dB. Aerated concrete and porous clay masonry are lighter and provide better thermal insulation as a single leaf, so sand-lime walls are always designed with an additional insulation layer. Industry comparisons (kb.pl, muratordom.pl) identify the same advantages: fire resistance, acoustics, price per m². Full comparison: sand-lime blocks, aerated concrete and clay masonry.

The block itself provides little thermal insulation (λ 0.41 W/m·K for BT24, 0.65 for BTA24 according to our declarations) — the insulation layer retains heat, while the wall provides load-bearing capacity and quiet. Calculation according to PN-EN ISO 6946 (R_si + R_se = 0.17): BT24 24 cm + 16 cm graphite EPS λ 0.031 gives U = 0.17 W/m²K, below the 0.20 required since 2021; with 20 cm, U = 0.14. Insulation thickness is therefore selected to meet the requirements rather than to suit the block.

Yes — and more easily than with a single-leaf wall. Passive house standards require wall U values of about 0.10–⁠0.15 W/m²K. A BT24 wall + 30 cm graphite EPS λ 0.031 has U = 0.10 W/m²K (BTA24 + 30 cm: 0.10), with a total thickness of 54 cm. A single-leaf 48 cm aerated concrete wall (λ about 0.10) gives U ≈ 0.20 — barely meeting WT 2021 and unsuitable for a passive house. In other words, appropriately thick EPS achieves what thermally insulating blocks promise, with even better results — together with the load-bearing capacity and quiet of heavy masonry.

Because it stores heat. A BTA24 wall weighs 416 kg/m² and a BT24 wall 315 kg/m², or 2–⁠3 times more than an aerated concrete wall. This mass heats up and cools down slowly: the house does not overheat on summer afternoons, temperatures do not drop sharply when heating is switched off in winter, and daily fluctuations are noticeably smaller. Combined with external insulation (mass inside, insulation outside), this is the most favourable arrangement for comfort — exactly how passive houses are built.

PN-B-02151-3:2015 requires R'_A1 ≥ 50 dB for walls between flats. From our method description (R'_A1 = R_w − C − K, K = 2 dB): BTA24 with 15 mm plaster gives 56 dB, BTA18 52 dB, BT18 51 dB and BT24 51 dB. We therefore recommend BTA24 or BTA18 for walls between flats (2–⁠6 dB margin for workmanship imperfections); BT12 suffices between rooms in one flat (R'_A1 46 dB with plaster).

Sand-lime material consists of lime, sand and water pressed under high pressure and steam-cured — a frost-resistant material that does not crumble from moisture like aerated concrete (whose high water absorption makes it unsuitable below ground level). For foundation and basement walls we use solid BTA24 and BTA18 blocks in class 20, always with damp-proofing (roofing felt on the footing, vertical waterproofing) — as described in our masonry instructions.

Blocks are 248 mm high and laid with 2 mm thin-bed adhesive mortar (250 mm course module), with tongue-and-groove vertical joints without mortar. Adhesive consumption in our offer: BTA8 — 1.1 kg/m², BT12 — 1.5 kg/m², BT18 — 2.3 kg/m². Traditional mortar (10 mm joint) requires 15.5 units/m² instead of 16, but laying is slower and less even — the first course always uses cement mortar, with adhesive from the second course.

Yes, without special anchors. Sand-lime material is dense (1.4–⁠2.0 t/m³) and homogeneous, so a standard expansion plug holds much more firmly than in aerated concrete or hollow clay blocks, which require chemical anchors or special plugs for porous materials. Drill with a masonry bit and hammer action; use a wall chaser, not a hammer, for service chases.

No — this is one of the less frequently mentioned advantages of hard masonry. Aerated concrete (2–⁠4 N/mm²) can be cut with an ordinary hand saw for wood; manufacturers advertise this as convenient on site, but the same property remains in the finished house. Imagine a detached garage at the back of a plot, screened from the street by a hedge: a door with a solid lock, an alarm sensor on the window — and an aerated concrete rear wall that can be cut through in a few dozen minutes of quiet sawing without touching the lock or alarm. Sand-lime material in class 15–⁠20 N/mm² stops the saw at its first tooth: cutting an opening requires a grinder with a diamond blade, electricity, dust and noise that no burglar would risk. That is why we build not only load-bearing walls but also garages, basements, stores and outbuildings with sand-lime blocks — wherever a wall must protect what is behind it. More comparisons: sand-lime blocks or aerated concrete.

The composition is exclusively sand, lime and water — no resins, foaming agents or chemical additives. The product is non-combustible (class A1), releases no volatile compounds, and lime's natural alkalinity discourages mould and fungi. The high wall mass also reduces outside noise — R_w from 44 dB (BTA8) to 60 dB (BTA24 with plaster).

Yes, with winter mortar and the temperature limits in our masonry instructions: light frost is permissible; stop work in stronger frost, and do not load fresh masonry horizontally until it has had a week of above-zero temperatures. Store blocks on pallets under film — never lay ice-covered units.

The factory is in Trąbki near Stargard (ul. Leśna 10, 73-121 Trąbki), about 20 km from Stargard and 56 km from Szczecin. Our sales office is in Szczecin at pl. Batorego 3.