Lignacite: Paint Grade Concrete Blocks Datasheet
Side view of a Lignacite Paint Grade Block.

Lignacite Paint Grade Concrete Blocks

Lignacite Paint Grade are fine-textured concrete blocks that are ideal for walls requiring direct decoration. They are tough, durable and suitable for all types of buildings.

Manufactured to BS EN 771-3, the blocks’ unique mix design (consisting of cement, fine aggregates and recycled graded-wood particles) accounts for their outstanding technical performance.

The 140mm width version (known as Lignacite SP) has a specially formulated mix that optimises the block density to produce a solid block with a unit weight of less than 20kg. There is a slight colour difference between Lignacite SP and 100mm Lignacite Paint Grade blocks.



Specification & Application

Weights & Pack Sizes

All weights are approximate and subject to normal variations in raw materials.

Table 1 – Block Weights and Pack Sizes

Size mm nominal
(L x W x H)
Unit weight
Laid weight inc. mortar
No. of blocks per pack
Solid 440 x 100 x 21514.915972
Solid SP 440 x 140 x 21519.220648
Table 1 Notes:
(1) Note: Weights are based on 3% moisture content by weight.
(2) Pack sizes may vary depending on the plant (Brandon or Nazeing) producing and delivering the blocks. For the most up-to-date information, please contact our Sales Team via or Alternatively, call our Head Office on 01842 810678.

Fire Resistance

Lignacite Paint Grade blocks are rated as Class A1 in accordance with BS EN 13501-1:2007+A1:2009. A1 materials are completely non-combustible and make no contribution to fire.

The fire resistance periods of Lignacite loadbearing and non-loadbearing walls are shown in Table 2, derived from the National Annex to BS EN 1996-1-2. This is applicable to all strengths of Lignacite.

The fire resistance of loadbearing walls is influenced by the proportion of the load on a wall, which is annotated in the National Annex as a ≤1.0 or a ≤0.6. The fire values presented are based on the worst loading case (≤1.0) and can therefore be safely used for all loading conditions.

The thicknesses shown are for masonry alone, excluding finishes. For the fire resistance of walls with finishes, refer to the Lignacite Design Guide – Fire Resistance.

Table 2 – Fire Resistance

Block type
(No finish)
Non-loadbearing wall
(criteria E1)
Loadbearing wall
(criteria RE1)
100mm solid2 hours2 hours
140mm solid SP4 hours3 hours
Table 2 Notes:
(1) Solid blocks are Group 1 units as defined in EN 1996-1-1

Sound Properties

Table 4 – Lignacite Wall with Acoustic Linings

Block TypeAcoustic LiningWeighted Sound Reduction Index Rw
100mm Lignacite Solid – Lining to one face50mm C stud built with 20mm gap from wall, 50mm Isover APR Insulation between studs, 12.5 Soundbloc plasterboard.60
140mm Lignacite SP – Lining to one faceIsowave 23 system fixed to one wall face.56
140mm Lignacite SP – Lining to both facesIsowave 23 system fixed to both wall faces.65
140mm Lignacite SP – Lining to one face50mm C stud built with 20mm gap from wall,

50mm Isover APR Insulation between studs,

12.5mm Soundbloc plasterboard.
215mm Lignacite (100mm blocks laid flat)50mm C stud built with 20mm gap from wall,

50mm Isover APR Insulation between studs,

12.5mm Soundbloc plasterboard.
Table 4 Notes:
(1) The Isowave system is supplied by Isomass Ltd.
(2) The acoustic lining should be adequately sealed at all exposed edges.

Thermal Properties

Cavity fill typeNo Finish
U-values (W/m² K)
100mm DriTherm Cavity Slab 32 Ultimate0.28
125mm DriTherm Cavity Slab 32 Ultimate0.23
150mm DriTherm Cavity Slab 32 Ultimate0.20
100mm Isover CWS 320.28
125mm Isover CWS 320.23
150mm Isover CWS 320.20
90mm Kingspan Kooltherm K106 (plus a 10mm cavity)0.19
115mm Kingspan Kooltherm K106 (plus a 10mm cavity)0.15
140mm Kingspan Kooltherm K106 (plus a 10mm cavity)0.13
90mm Eurowall + (plus a 10mm cavity)0.21
115mm Eurowall + (plus a 10mm cavity)0.17
140mm Eurowall + (plus a 10mm cavity)0.14
100mm Xtratherm Cavity Therm0.20
125mm Xtratherm Cavity Therm0.16
150mm Xtratherm Cavity Therm0.14
Cavity fill typeNo Finish
U-values (W/m² K)
60mm Celotex CW40000.26
75mm Celotex CW40000.22
100mm Celotex CW40000.18
60mm Kingspan Kooltherm K1080.24
75mm Kingspan Kooltherm K1080.20
100mm Kingspan Kooltherm K1080.16
60mm Eurowall Cavity0.26
75mm Eurowall Cavity0.22
100mm Eurowall Cavity0.18
100mm Rockwool Partial Fill0.28
150mm Rockwool Partial Fill0.20
170mm Rockwool Partial Fill0.18
100mm Isover CWS 320.27
125mm Isover CWS 320.22
150mm Isover CWS 320.19
Cavity Fill Table's Notes:
(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 (m² K/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 (always check the manufacturer’s guidance).



Block Mortar

Generally, the mortar type for work above ground level should be designation (iii) / Compressive Class M4. Stronger mixes may be required if blocks are used below ground.

Table 7 – Mortar Mixes

Mortar Designation
(as per BS 5628-3)
Compressive Strength Class
(as per BS EN 1996)
Recommended mix proportions of materials by volume
(iii)M41:1:5 to 6 - Cement:Lime:Sand.
1:5 to 6 - Cement:Sand with or without air entrainment.
1:4 to 5 - Masonry Cement:Sand (with non-lime filler).
1:3½:4 - Masonry Cement:Sand (with lime filler).
(ii)M61:½:4-4½ - Cement:Lime: Sand.
1:3 to 4 - Cement:Sand with or without air entrainment.
1:2½:3½ - Masonry Cement:Sand (with non-lime filler).
1:3 - Masonry Cement:Sand (with lime filler).

Site Practice

Block Surface Finish Recommendations

Direct Painting

A mist coat followed by at least two coats of emulsion will provide a good finish. The actual coverage will depend on the quality of the paint and how it is applied (e.g., brush, roller or by spray). Always ensure that each coat of paint has fully dried before any further layers are added.

Block Safe Handling

For detailed advice, refer to Lignacite’s Sitework Guide and the Material Safety Data sheet.

  • Block packs may be stacked on firm and level surfaces to a maximum height of 2 packs. Consideration of handling equipment’s suitability for site terrain and safety limits should also be given. Hand-operated pallet trucks may not be suitable unless pallets specific for this purpose are used and loads do not exceed the limits of the pallet truck or its operator(s). Care should be taken when opening packs that are wrapped or banded to ensure that items do not fall or otherwise endanger persons handling the blocks or those nearby.
  • Handling of blocks should be undertaken in accordance with HSE Construction Sheet No. CIS77 ‘Preventing injury from handling heavy blocks’ (Construction Industry Advisory Committee) and in accordance with the Manual Handling Regulations 1992 (as amended). This concludes that there is a high risk of injury to individuals who repetitively manually handle blocks in excess of 20 kg. Where practical, mechanical handling equipment should be used to transport block packs to the area of work.
  • Blocks should not be installed if the temperature is at or below 3°C and falling.
  • Blocks should always be laid on a full bed of mortar and vertical joints solidly filled.
  • For walls built fair, sample panels are recommended and should be built prior to commencing block laying. This will serve as a benchmark for defining and specifying the quality of work required.
  • Please note that for Paint Grade products, colour consistency is not guaranteed. It is advisable to view sample panels at a distance of approximately 3m from the wall in good natural light.

Lignacite block:

Datasheet View our EPDs Make an Enquiry Specify a Block

Product data updated: 30th Mar 2024

Google HQ: Bearing The Weight Of A Grand Vision


Read Case Study

Rising Sun Hill: Fine-Tuned From The Fabric To The Finish


Read Case Study

22 Bishopsgate: Building The Heart Of A Vertical Village

Mixed Use

Read Case Study

The Paddocks: Character With Carbon Consciousness


Read Case Study

The Building Blocks of Sustainability: A Case Study

Read Case Study

One Broadgate: A sustainable statement


Read Case Study

The Whiteley: Bespoke Blockwork For A Unique Restoration

Mixed Use

Read Case Study

Aerial Image of Rising Sun Hill, Rattlesden.
22 Bishopsgate.
Lignacite - The Building Blocks of Sustainability: A Case Study
Construction photo of The Whiteley.