LIGNACITE

Lignacite – A range of fine textured, loadbearing blocks, suitable for use in commercial and housing projects. Fair-Faced and Paint-Grade blocks can be used to construct internal walls in commercial, industrial and leisure buildings. Select from a range of sizes, strengths and grades for total design flexibility.

LIGNACITE - MEDIUM DENSE BLOCK
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SPECIFICATIONS AND DATA

A range of fine textured, loadbearing units, suitable for facing and general purpose applications. Select from a range of sizes, strengths and grades for total design flexibility.

General Properties – Table 1

Face Size 440mm x 215mm
Dimensional Tolerances Category: D1
Mean Unit Strength 3.6, 7.3, 10.4N/mm2
Net Dry Density Lignacite (all strengths): 1570kg/m3 Lignacite SP: 1450kg/m3
Thermal Conductivity

@ 3% moisture content

Lignacite (all strengths): 0.90W/mK Lignacite SP: 0.79 W/mK
Moisture Movement <0.7mm/m
Reaction to Fire Class A1
Air Tightness  
Configuration Solid Blocks: Group 1,  Cellular & Hollow Blocks: Group 2
Specific Heat Capacity 1000 J/kg/K
Water Vapour Diffusion Coefficient µ =  5/15 (Tabulated value from BS EN 1745)

Note:

(1) Cellular and hollow blocks are produced in 3.6 and 7.3N/mm2 strengths

(2) Based on blocks painted to both faces

  • Medium density fine textured blocks in Fair-Faced, Paint-Grade and Standard block finish
  • For use internally and externally above and below ground
  • High levels of air tightness, sound insulation and fire resistance.

Lignacite blocks are available in the following grades:

  • Fair-Faced. For locations requiring a consistent colour and close textured block face. (When ordering please state blocks are for Fair-Faced use)
  • Paint-Grade. For locations where a consistent close textured face is required as a background for direct painting
  • Standard. For locations where the surface will not be visible eg. plastered, use below ground

Lignacite SP is available in a 140mm width solid block. It consists of a specially formulated mix which reduces the block density to produce a solid block under 20kg unit weight. It is available in all grades. There is a slight colour difference between the traditional block and the Lignacite SP.

Sustainability

Responsible sourcing – Lignacite Ltd operates its manufacturing plants to a BSI certified Environmental Management System (EMS) complying with ISO14001. Lignacite Ltd. complies with the requirements of BES 6001– Framework Standard for the Responsible Sourcing of Construction Products, Certificate No: BES 580823. This independently confirmed Responsible Sourcing Certification provides re-assurance to our customers that they are procuring products responsibly and sustainably. Credits can also be gained under environment assessment schemes such as BREEAM and the Code for Sustainable Homes.

Environmental ratings – Summary green guide ratings applicable to Lignacite blocks can be obtained from the BRE Green Guide to Specific Guide to Specification.

Thermal Bridging

A significant factor in thermal assessments is the heat loss through thermal bridges (known as non–repeating or linear thermal bridges). These occur at junctions between elements or where the continuity of the external fabric insulation is interrupted (e.g. at junctions with external walls, floors and roof). Assessors will need to apply a PSI (y) value to the particular junction being measured.

The Concrete Block Association (CBA) have developed a comprehensive set of junctions that have been independently assessed. The results clearly demonstrate that constructions using Lignacite aggregate blocks can be assigned improved performance when compared to the Government’s Accredited Construction Details and Default values shown in Appendix K of SAP 2012.

As a member of the CBA, Lignacite Ltd is able to advocate the use of these enhanced bridging details. This information will be of interest to designers and SAP assessors as well as builders who will have the responsibility for correctly constructing the various junctions.

Junction details and PSI (y) values can be accessed at www.cba-blocks.org.uk

Design

The design of walls incorporating Lignacite blocks should be in accordance with relevant design standards including BS 8103 Part 2 and BS EN 1996-1-1 and requirements of the Building Regulations.

Surface Finish Recommendations

Drylining – Application to be as manufacturer’s recommendations.

Dense Plaster – Apply either 1:1:6 cement:lime:sand or 1:4 ½ Masonry cement:sand or 1:5 ½ cement;sand and plasticiser. Alternatively: Thistle Bonding or Thistle Hardwall or Knauf Ultimate backing plaster.

Finishing Coats – Thistle plaster finish or Thistle multi-finish or Knauf Multi cover.

External Rendering – Rendering to be in accordance with BS EN 13914-1. Avoid over strong mixes. Ensure the first coat of render is applied to a greater thickness than successive coats. An initial spatterdash coat is advisable, consisting of 1 part cement, 1 part sand, gauged with a proprietary bonding agent (SBR). Builders considering the use of proprietary render systems must exercise caution to accurately adhere to the render manufacturers’ design and specification instructions. Detailed guidance is also published in the NHBC Standards, Chapter 6.11- Render.

Strictly adhere to the specific application instructions, paying particular attention to prevailing weather conditions and the minimum recommended thickness of single coat renders.

Standards

Lignacite blocks are BSI Kitemarked approved to BS EN 771-3. They are Category 1 masonry units manufactured under a BSI certified Quality System complying with BS EN 9001.

Unit and Laid Weights

Unit and laid weights (including mortar) are shown in Table 2. All weights are approximate and subject to normal variations in raw materials.

Block Weights – Table 2

Width

(mm)

Form Unit Weight (kg) Laid Weight

(kg/m2)

75 Solid 11.1 118
100 Solid 14.9 159
140 Solid SP 19.2 206
140 C/H 15.3 168
190 Solid 28.2 301
190 Hollow 19.0 210
215 Solid 31.9 340
215 Hollow 20.8 231
Note: Weights are based on 3% moisture content by weight. 

Thermal Resistance

The thermal resistance values (m 2 K/W) for Lignacite are shown in Table 3. The values are derived by dividing the block thickness by its thermal conductivity (W/mK).

Thermal Resistances – Table 3

Thermal Resistance (m2 K/W)
Width

(mm)

Form 3%

m/c

100 Solid 0.111
140 Solid SP 0.177
140 C/H 0.210
190 Solid 0.211
190 Hollow 0.246
215 Solid 0.239
215 Hollow 0.258
Note: 3% moisture content (m/c) should be used for protected locations such as the inner leaf, and 5% for exposed locations such as the outer leaf when rendered.

Fire Resistance

The fire resistance periods of Lignacite loadbearing and non-loadbearing walls are shown in Tables 5a and 5b. The data is derived from BS EN 1996-1-2.

This data is are only valid for walls complying with BS EN 1996 Part 1-1, Part 2 and Part 3. For walls designed in accordance with BS 5628, fire resistance values can be confirmed with our Technical Department.

The thicknesses given in the Table 5a and 5b are for masonry alone, excluding finishes. For the fire resistance of walls with finishes, refer to the Lignacite Design Guide – Fire Resistance.

Fire resistance of Lignacite solid blocks – Table 5a

Solid blocks (Group 1 units) –

no finish

Non-loadbearing wall

(criteria E1)

Loadbearing wall

(criteria RE1)

a 1.0 a 0.6
75mm 1 hour 1 hour
100mm 3 hours 2 hours 3 hours
140mm 4 hours 3 hours 4 hours

Fire resistance of Lignacite cellular and hollow blocks – Table 5b

Cellular and

hollow blocks (Group 2 units) –

no finish

Non-loadbearing wall

(criteria E1)

Loadbearing wall

(criteria RE1)

a 1.0 a 0.6
100mm 1 hours 1 hours 1.5 hours
140mm 3 hours 3 hours 3 hours

Note:

  1. These Tables are only valid for walls complying with BS EN 1996 Part 1-1,

Part 2 and Part 3. For walls designed in accordance with BS 5628, fire

resistance values from that Standard are available on request. 

  1. Criteria E1 refers to walls with a separating function. Criteria RE1 refers to walls with a separating and load bearing function.
  2. This Table is derived on data from the National Annex to BS EN 1996-1-2. References to a ≤ 1.0 and a ≤ 0.6 refer to the proportion of load on a wall.

If unknown, we suggest the values for a ≤ 1.0 are used as these are ‘worst case’ values.

Appearance

Lignacite blocks are medium grey in colour with a fine textured surface. Solid, cellular, and hollow block types are available.

Applications

Lignacite blocks are suitable for use in commercial and housing projects. Fair-Faced and Paint-Grade blocks can be used to construct internal walls in commercial, industrial and leisure buildings. Lignacite blocks can be used in the following locations:

  • The inner and outer leaves of external cavity walls
  • Internal walls including fire break walls
  • Separating walls including those conforming to Robust Detail specifications
  • External and internal walls below ground (3.6N/mm 2 blocks can be used in both inner leaf and internal walls;

7.3N/mm 2 blocks to other locations)

  • Infill units to beam and block flooring
  • Fair-Faced blocks are recommended for internal use

Mortar

The mortar type for work above ground level should be designation (iii) / Compressive Class M4. Stronger mixes may be used only with the permission of the designer. Stronger mixes may also be required for work below ground in accordance with PD 6697.

Thermal Insulation

Lignacite blocks can be used to satisfy the requirements of Part L of the Building Regulations.

Presented are the U-values for a range of wall constructions based on 100mm Lignacite blocks blocks in conjunction with full and partial cavity insulation. The outer leaf is facing brick, but a rendered block outer leaf will usually achieve at least the same U-value.

For constructions not shown please contact our Technical Department (tel 01842 810678) who will be pleased to provide confirmation of performance.

Full Cavity Fill and 100mm Lignacite blocks

U-values (W/m K2)

 

Cavity fill type

No finish (eg Paint Grade block) 12.5mm plasterboard    on dabs 13mm lightweight plaster
Internal finish
100mm DriTherm Cavity Slab 32 Ultimate 0.28 0.27 0.28
100mm DriTherm Cavity Slab 34 Super 0.30 0.28 0.29
100mm Isover CWS 32 0.28 0.27 0.28
100mm Isover CWS 36 0.31 0.30 0.31
100mm Xtratherm Cavity Therm 0.20 0.19 0.19
100mm Kingspan Kooltherm K106 0.18 0.17 0.18
125mm DriTherm Cavity Slab 32 Ultimate 0.23 0.22 0.23
125mm DriTherm Cavity Slab 34 Super 0.25 0.23 0.24
125mm Isover CWS 32 0.23 0.22 0.23
125mm Isover CWS 36 0.26 0.25 0.25
125mm Xtratherm Cavity Therm 0.16 0.16 0.16

Partial Cavity Fill and 100mm Lignacite blocks

U-values (W/m K2)

 

Cavity fill type

No finish (eg Paint Grade block 12.5mm plasterboard    on dabs 13mm lightweight plaster
Internal finish
50mm Celotex CW4000 0.30 0.28 0.29
50mm Kingspan Kooltherm K108 0.26 0.25 0.26
60mm Celotex CW4000 0.26 0.25 0.26
60mm Kingspan Kooltherm K108 0.23 0.22 0.22
75mm Celotex CW4000 0.22 0.21 0.22
75mm Kingspan Kooltherm K108 0.19 0.18 0.19

Notes to tables: 

  1. The U-values shown are based on the use of various proprietary insulation products. Alternative products can be used, provided they can achieve an equivalent thermal resistance (m2K/W).
  2. Wall ties are assumed to be stainless steel with a cross-sectional area of no more than 12.5mm2 for structural cavities up to 125mm wide.
  3. The suitability of full fill cavity insulation materials will depend on exposure conditions and should be confirmed by the designer. For partial cavity fill, a 50mm residual should be maintained. In some cases it may be possible to reduce the cavity width to a minimum of 25mm. The insulation manufacturer should be consulted for guidance.

Thermal Bridging

A significant factor in thermal assessments is the heat loss through thermal bridges (known as non–repeating or linear thermal bridges). These occur at junctions between elements or where the continuity of the external fabric insulation is interrupted (e.g. at junctions with external walls, floors and roof). Assessors will need to apply a PSI (y) value to the particular junction being measured.

The Concrete Block Association (CBA) have developed a comprehensive set of junctions that have been independently assessed. The results clearly demonstrate that constructions using Lignacite aggregate blocks can be assigned improved performance when compared to the Government’s Accredited Construction Details and Default values shown in Appendix K of SAP 2012.

As a member of the CBA, Lignacite Ltd is able to advocate the use of these enhanced bridging details. This information will be of interest to designers and SAP assessors as well as builders who will have the responsibility for correctly constructing the various junctions.

Junction details and PSI (y) values can be accessed at www.cba-blocks.org.uk

Movement Control

Movement joints should be considered in accordance with PD 6697 at approximately 6.0 metre spacings. In areas of concentrated stress, such as those above and below openings, consideration should be given to the use of bed joint masonry reinforcement.

Sound Insulation

The Weighted Sound Reduction Index (Rw) values of various Lignacite wall constructions are shown in Tables 4(a) and 4(b). Table 4(a) presents sound values for Lignacite blockwork with conventional finishes. Table 4(b) presents values for Lignacite blockwork with acoustic linings to one or both sides of the wall. These constructions will be of interest where higher levels of sound insulation are required without increasing the block wall thickness and are based on the use of 100mm and 140mm Lignacite blocks in conjunction with proprietary acoustic panels. These enhanced constructions have the capability to achieve a sound reduction in excess of 60 Rw (dB).

Sound Reduction – Lignacite wall with conventional finishes Table 4a

Weighted Sound Reduction Index Rw (dB)
Wall

Width

(mm)

Block Type L/tweight Plaster Dry

Lined

Paint

Finish

Fair

Faced

75 Solid 43 45 40 39
100 Solid 47 47 47 46
140 Solid SP 51 51 50 49
140 Cellular/Hollow 49 49 47 47
190 Solid 54 53 54 53
190 Hollow 50 50 50 49
215 Solid 54 55 55 54
200-215 Collar Jointed Wall

2x100m

leaves laid back to back (1)

52 52 51 51
215 Hollow 51 51 51 50
275 Cavity Wall

2x100m

leaves with a 75mm cavity

54 54 53 52
340 Cavity Wall

100mm Solid blocks and 140mm

LignaciteSP blocks with a 100mm cavity

57 57 56 55

(1)  2 leaves of 100mm solid blocks laid back to back and tied together.

Note:

  1. The above values are based on technical assessments and tests to BS EN

    ISO 140-3.

  1. Surface finishes are assumed to be applied to both wall faces.
  2. Cavity walls tied together using Type 4/Type A wall ties e.g. Ancon Staifix HRT4

Sound Reduction – Lignacite wall with acoustic linings – Table 4b

Block Type Acoustic Lining Specification Weighted Sound Reduction Index Rw (dB)
100mm Lignacite Solid – Lining to one face Isowave 23 system fixed to one wall face. 64
140mm Lignacite SP – Lining to one face Isowave 23 system fixed to one wall face. 56
140mm Lignacite SP – Lining to both faces Isowave 23 system fixed to both wall faces. 65
140mm Lignacite SP – Lining to one faces 50mm C stud built with  20mm gap from wall, 50mm Isover APR Insulation,

12.5mm Soundbloc plasterboard

65

Note: The Isowave system is supplied by Isomass Ltd. www.isomass.co.uk

100mm Lignacite solid blockwork with acoustic lining to one side. Sound insulation = 64 Rw, dB

140mm Lignacite SP blockwork with acoustic lining to one side. Sound insulation = 56 Rw, dB

140mm Lignacite SP blockwork with acoustic lining to both sides. SRL TEST c flooring systems Sound insulation = 65 Rw, dB

140mm Lignacite SP blockwork with acoustic lining to one side. Sound insulation = 65 Rw, dB