Silka Brochure - CS Blocks – The Efficient Choice in Construction

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Technical Data – Small Format Silka CS Blocks

Thin Bed Mortar Blocks – Light (LBL)

Dimensions (mm)	Avg. Compressive Strength (N/mm²)	Kg/pc	Pc/m²	Thin Joint Mortar (kg/m²)*
LBL 10 low 298 x 100 x 148	≥ 15	6.19	22.20	5.40
LBL 10 high 298 x 100 x 198	≥ 15	8.74	16.70	4.10
LBL 15 low 298 x 150 x 148	≥ 15	10.73	22.20	8.00
LBL 15 high 298 x 150 x 198	≥ 15	11.96	16.70	6.20
LBL 20 low 298 x 200 x 148	≥ 15	14.54	22.20	11.00
LBL 20 high 298 x 200 x 198	≥ 15	16.78	16.70	8.40

Thin Bed Mortar Blocks – Light (LBL)

These small format light blocks (LBL) are designed for quick and efficient construction using thin joint mortar. They provide a minimum compressive strength of 15 N/mm² and come in a variety of sizes (100–200 mm thickness, 148–198 mm height). The weight per block ranges from 6.19 kg to 16.78 kg, with mortar usage between 4.10 and 11.00 kg/m² depending on block dimensions. The LBL blocks are ideal for non-load-bearing walls or partition walls and are optimized for thin joint construction with minimal finishing requirements.

Thin Bed Mortar Blocks – Full (LB)

Dimensions (mm)	Avg. Compressive Strength (N/mm²)	Kg/pc	Pc/m²	Thin Joint Mortar (kg/m²)*
LB 10 low 298 x 100 x 148	≥ 25	7.62	22.20	4.70
LB 10 high 298 x 100 x 198	≥ 25	10.53	16.70	3.50
LB 15 low 298 x 150 x 148	≥ 25	11.79	22.20	7.40
LB 15 high 298 x 150 x 198	≥ 25	16.19	16.70	5.60
LB 20 low 298 x 200 x 148	≥ 25	16.00	22.20	9.50
LB 20 high 298 x 200 x 198	≥ 25	22.23	16.70	7.20

Thin Bed Mortar Blocks – Full (LB)

The full blocks (LB) are heavier and stronger than the LBL variety, with a minimum compressive strength of 25 N/mm². They are suitable for load-bearing walls, available in thicknesses of 100–200 mm, and heights of 148–198 mm. Block weights range from 7.62 kg to 22.23 kg, with mortar usage from 3.50 to 9.50 kg/m². LB blocks also use thin joint mortar and allow for efficient assembly with minimal finishing, supporting both structural and partition wall applications.

Chamfered Blocks (VB)

Dimensions (mm)	Avg. Compressive Strength (N/mm²)	Kg/pc	Pc/m²	Thin Joint Mortar (kg/m²)*
LBL 10 low 298 x 100 x 148	≥ 15	6.63	22.20	4.60
LBL 10 high 298 x 100 x 198	≥ 15	8.63	16.70	3.50
LBL 15 low 298 x 150 x 148	≥ 15	9.06	22.20	7.00
LBL 15 high 298 x 150 x 198	≥ 15	11.98	16.70	5.20
LBL 20 low 298 x 200 x 148	≥ 15	12.75	22.20	9.30
LBL 20 high 298 x 200 x 198	≥ 15	16.45	16.70	7.00

*Thin joint mortar usage includes waste and spillage, applied on the top side of blocks.

Chamfered Blocks (VB)

Chamfered blocks (VB) are designed for aesthetic and functional applications, including fair-faced walls. They have the same compressive strength as the LBL blocks (≥15 N/mm²) and come in the same range of thicknesses and heights. Weight per block ranges from 6.63 kg to 16.45 kg, with mortar consumption from 3.50 to 9.30 kg/m². The chamfered design allows walls to be left unplastered and reduces finishing work, while still supporting thin joint mortar construction.

Discover the Simplicity of Silka CS Blocks

Silka CS blocks combine the specific qualities of calcium silicate—sound insulation, high load-bearing capacity, and thermal efficiency—with outstanding efficiency and dimensional stability.

Key Advantages:

Ideal for use with thin joint mortars.
Finishing options: no pointing required, tile directly, or apply thin plaster.
Chamfered blocks can be left fair-faced.
LB and LBL blocks: double tongue and groove for easy assembly.
VB chamfered blocks: tongue and groove connection for precision.
Free project-oriented advice and site service from Xella: 0870 609 0306.

Which Tools Do You Need?

For constructing with Silka thin bed mortar blocks:

Thin bed mortar applicator
Electric mixer and trough
Classic mason tools (trowel, hammer, trimming knife)
Manual block grab
Mechanical block cutting device or milling machine
Thin joint mortar

Thin Joint Mortar (Silkafix)

Supplied in 25 kg bags (summer or winter quality).
Mix 25 kg powder with 6 liters of cold water for at least 4 minutes.
Small quantities can be mixed in a bucket.
Usage period: 4 hours (winter mortar max 2 hours).
Place blocks within 15 minutes of application.

Kicker Course Construction

The first course is placed on traditional mortar to ensure level correction for irregular floors.
Allow at least 1 day for setting before continuing with Silka CS blocks.

Application of Thin Joint Mortar

Use thin joint mortar applicators and scoops for even application.
Apply to a maximum of 3 meters of wall in dry conditions.
Brush blocks with water before applying mortar for optimal adhesion.

Placing Silka CS Blocks

Place blocks on the thin joint mortar bed and adjust using a soft-faced hammer.
Ergonomic hand grips make lifting easy; manual block grabs available.

Cutting Special Blocks to Size

Non fair-faced masonry: Silka CS block-cutting device.
Fair-faced masonry: Table saw or right-angle disc grinder for precise edges.
Chamfered edges: Chamfered edge template.

Anchoring Materials

Stainless steel cavity wall anchors (7 pcs/m²) with plastic lip-clips.
Thin joint mortar coupling strips for adjoining walls.

Movement Joints

Used to manage large buildings’ structural movements.
Maximum spacing depends on wall thickness and reinforcement (NBN B 24-401, STS 22).
PVC scrim tape can be used for plastered walls.

Removing Excess Mortar & Protecting Walls

Wait a few hours before removing mortar with putty knife or brush.
Protect finished walls from rain or frost using plastic covers.

Drilling Work Minimized

LBL and VB blocks have pre-aligned drill-hole patterns for conduits and pipes.
Electrical boxes can be installed easily.

Wall Finishing & Anchoring

Apply thin coat plaster, traditional plaster, tiles, or paint directly.
Suitable for heavy objects; standard nylon wall plugs suffice.

Chamfered Block Specifics

Each course must be perfectly level.
Tongue and groove connection ensures accuracy.
Wait 20 minutes before removing excess mortar.
Cutting with table saw or disc grinder; chamfer edges with template.
Minimal chasing required for electrical installations.

Large Format Silka CS Elements

Modular sizes: 897 or 997 mm length, 543 or 643 mm height, thickness 100–300 mm.
Special pieces factory-cut according to approved drawings.
Delivered and installed using a small crane for efficiency.

Element	Dimensions (mm)	Compressive Strength (N/mm²)	Kg/pc	Pc/m²	Mortar Usage (kg/m²)	Acoustic Qualities (dB)
E 100 low	897/997 x 100 x 543	≥ 25	94.74	1.85	1.60	43
E 100 high	897/997 x 100 x 643	≥ 25	112.19	1.56	1.40	43
E 150 low	897/997 x 150 x 543	≥ 25	142.11	1.85	2.50	50
E 150 high	897/997 x 150 x 643	≥ 25	168.28	1.56	2.20	50
E 175 low	897/997 x 175 x 543	≥ 25	165.79	1.85	3.00	52
E 175 high	897/997 x 175 x 643	≥ 25	196.33	1.56	2.50	52
E 214 low	897/997 x 214 x 543	≥ 25	202.74	1.85	3.60	55
E 214 high	897/997 x 214 x 643	≥ 25	240.08	1.56	3.00	55
E 300 low	897/997 x 300 x 543	≥ 25	184.22	1.85	5.00	58
E 300 high	897/997 x 300 x 643	≥ 25	336.56	1.56	4.40	58

Large Format Silka CS Elements (E)

The large format Silka CS elements are intended for large-scale projects and load-bearing construction. Available in lengths of 897 or 997 mm, heights of 543 or 643 mm, and thicknesses from 100–300 mm, they offer compressive strength ≥25 N/mm². Block weights range from 94.74 kg to 336.56 kg, with mortar usage from 1.40 to 5.00 kg/m². Acoustic performance ranges from 43–58 dB depending on size. Factory-cut special pieces ensure fast, precise installation with minimal on-site modification.

General Silka CS Blocks FAQs

Q1: What are Silka CS blocks?
A: Silka CS blocks are calcium silicate masonry units that combine sound insulation, high load-bearing capacity, and thermal efficiency. They are dimensionally stable, suitable for thin joint mortar construction, and allow for various finishing options such as tiling, plastering, or leaving fair-faced.

Q2: What types of Silka CS blocks are available?
A: There are three main types:

Thin Bed Mortar Light Blocks (LBL) – small format, ≥15 N/mm² compressive strength, lightweight.
Thin Bed Mortar Full Blocks (LB) – stronger blocks for load-bearing walls, ≥25 N/mm².
Chamfered Blocks (VB) – aesthetic blocks for fair-faced walls, ≥15 N/mm².

Q3: What are the main advantages of Silka CS blocks?
A: Advantages include:

Ideal for thin joint mortar construction.
Minimal finishing required.
Chamfered blocks can be left unplastered.
Ergonomic design with tongue and groove connection.
Free project-oriented advice and on-site service from Xella.

Thin Bed Mortar Blocks – Light (LBL) FAQs

Q4: What are the sizes and weights of LBL blocks?
A: LBL blocks come in thicknesses of 100–200 mm, heights of 148–198 mm, and weights ranging from 6.19 kg to 16.78 kg per block.

Q5: What is the compressive strength of LBL blocks?
A: All LBL blocks have a minimum compressive strength of 15 N/mm².

Q6: How much thin joint mortar is needed?
A: Mortar usage ranges from 4.10 to 11.00 kg/m², depending on block size. This includes waste and spillage.

Q7: What applications are LBL blocks suitable for?
A: LBL blocks are ideal for non-load-bearing or partition walls, and they are optimized for fast thin joint mortar construction.

Thin Bed Mortar Blocks – Full (LB) FAQs

Q8: What are the sizes and weights of LB blocks?
A: LB blocks come in thicknesses of 100–200 mm, heights of 148–198 mm, and weights ranging from 7.62 kg to 22.23 kg per block.

Q9: What is the compressive strength of LB blocks?
A: LB blocks have a minimum compressive strength of 25 N/mm², making them suitable for load-bearing applications.

Q10: How much thin joint mortar is required?
A: Mortar usage ranges from 3.50 to 9.50 kg/m², depending on the block dimensions.

Q11: What are LB blocks typically used for?
A: LB blocks are suitable for structural and partition walls, providing high strength while allowing thin joint mortar construction for efficiency.

Chamfered Blocks (VB) FAQs

Q12: What are the dimensions and weights of VB blocks?
A: VB blocks have the same thickness (100–200 mm) and heights (148–198 mm) as LBL blocks, with weights ranging from 6.63 kg to 16.45 kg.

Q13: What is the compressive strength?
A: Chamfered VB blocks have a compressive strength of ≥15 N/mm².

Q14: How much mortar is required?
A: Mortar usage ranges from 3.50 to 9.30 kg/m².

Q15: What makes VB blocks unique?
A: Chamfered blocks allow fair-faced wall construction, reduce finishing work, and feature tongue and groove connections for precise assembly.

Construction & Handling FAQs

Q16: What tools are required for Silka CS block construction?
A: Essential tools include a thin bed mortar applicator, electric mixer, trowel, hammer, trimming knife, manual block grab, and block-cutting devices.

Q17: How is thin joint mortar mixed and applied?
A: Mix 25 kg of Silkafix powder with 6 liters of cold water for at least 4 minutes. Apply within 15 minutes of mixing, with small quantities usable in a bucket. Winter mortar is suitable for up to –5°C.

Q18: What is a kicker course and why is it important?
A: The kicker course is the first course of blocks laid on traditional mortar to ensure level walls. It should set for at least 1 day before continuing with thin joint mortar construction.

Q19: How are special blocks cut?
A: Non fair-faced blocks: Silka CS block-cutting device.
Fair-faced blocks: Table saw or disc grinder; chamfered edges with template.

Q20: How are walls protected and finished?
A: Remove excess mortar after a few hours. Protect walls from rain/frost with plastic covers. Finish with thin coat plaster, traditional plaster, tiles, or paint directly. Heavy objects can be anchored using standard nylon plugs.

Large Format Silka CS Elements FAQs

Q21: What sizes and strengths are available?
A: Sizes: 897/997 mm length, 543/643 mm height, 100–300 mm thickness.
Compressive strength: ≥25 N/mm².

Q22: What are the block weights and mortar usage?
A: Weights: 94.74–336.56 kg per block. Mortar: 1.40–5.00 kg/m².

Q23: What are the acoustic properties?
A: Sound insulation ranges from 43–58 dB depending on the block size.

Q24: How are large format elements installed?
A: Special pieces are factory-cut based on drawings and installed using a small crane for fast, efficient construction with minimal on-site modification.