Lignacrete Paint Grade Concrete Block
Lignacrete Paint Grade are close textured concrete blocks, which are ideal for walls that require direct decoration. Manufactured to BS EN 771-3, these blocks are tough, durable and suitable for all types of buildings.
Generally, 100mm, 140mm and 215mm blocks have a face size of 440mm x 215mm. Lignacrete 140mm Midi blocks have a face size of 290mm x 215mm and have been developed for ease of handling while maintaining all the performance of conventional size solid units.Datasheet
Suitable for use in academic, commercial and leisure buildings, where durable and impact-resistant walls are needed.
A1 Fire Rated
These non-combustible blocks make no contribution to fire, earning them a Class A1 rating.
Excellent Sound Insulation
The high mass of Lignacrete results in outstanding acoustic performance, with a 140mm wall providing sound insulation in excess of 50dB (Rw).
Specification & Application
Lignacrete Paint Grade blocks are BSI Kitemarked and certified to BS EN 771-3. They are also Category 1 masonry units manufactured under a BSI certified Quality Management System, which is BS EN 9001 compliant.
Lignacrete Paint Grade are medium grey to buff in colour. These blocks are not fair-faced and thus colour consistency is not guaranteed.
For use in walls where a direct decoration finish is required e.g., emulsion paint. Walls of 210-215mm thickness are recommended to be constructed using two leaves of 100mm blocks laid back-to-back and suitably tied. This construction is known as a collar-jointed wall.
Typical locations include:
- The inner leaves of external cavity walls
- Internal walls, including fire break walls
- Separating walls
|Face Size||440mm x 215mm.290mm x 215mm (Midi blocks).|
|Thickness||100mm, 140mm,215mm (hollow only)|
|Mean Unit Strength||7.3N/mm², 10.4N/mm²|
|Configuration||Group 1, solid blocks.Group 2, hollow blocks.|
|Dimensional Tolerances||Category D1|
|Net Dry Density||2000 kg/m³|
|Thermal Conductivity||1.33 W/mK at 3% moisture content (internal use)|
|Airtightness (m³/hr/m²)No finish||100mm solid blocks: 2.73.140mm solid blocks: 3.36.|
|Airtightness (m³/hr/m²)Paint one side||100mm solid blocks: 0.88.140mm solid blocks: 1.72.|
|Reaction to Fire||Class A1|
(1) Airtightness results for painted walls are based on the use of Paint Grade blocks and standard emulsion paint.
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)
|Laid weight inc. mortar|
|No. of blocks per pack|
|No. of blocks per pack|
|Solid 440 x 100 x 215||18.9||198||64||64|
|Solid 440 x 140 x 215||26.5||278||64||64|
|Solid 290 x 140 x 140 (Midi size)||17.5||279||48||48|
|Hollow 440 x 140 x 215||19.0||204||60||48|
|Hollow 440 x 215 x 215||25.1||274||40||32|
(1) 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 firstname.lastname@example.org or email@example.com. Alternatively, call our Head Office on 01842 810678.
Lignacrete blockwork provides excellent levels of sound insulation between buildings and adjoining rooms. The Weighted Sound Reduction Index (Rw) values of various Lignacrete wall constructions are shown in Table 2.
Table 2 – Sound Reduction Values
Weighted Sound Reduction Index: Rw, (dB):
|No finish||Paint finish|
(1) Sound insulation values are based on technical assessments and tests to BS EN ISO 140-3.
(2) Paint finish is based on emulsion paint and applied to both wall faces.
Lignacrete 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 Lignacrete loadbearing and non-loadbearing walls are shown in Table 3, derived from the National Annex to BS EN 1996-1-2. This is applicable to all strengths of Lignacrete. 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 3 – Fire Resistance
(Group 2 units) No finish
|100mm solid||3 hours||2 hours|
|140mm solid||4 hours||3 hours|
|140mm Hollow||3 hours||3 hours|
|215mm Hollow||4 hours||4 hours|
(1) Solid blocks are Group 1 units as defined in EN 1996-1-1
(2) Hollow blocks are Group 2 units as defined in EN 1996-1-1
The thermal resistance values (m² K/W) for Lignacrete Paint Grade blocks are shown in Table 4. For solid blocks, the values are calculated by dividing the block thickness by its thermal conductivity (W/mK).
Table 4 – Thermal Resistance Values
(m² K/W): 3% m/c
(1) 3% moisture content (m/c) should be used for protected locations, such as the inner leaf of external cavity walls.
Presented in the tables are the U-values for a range of wall constructions based on 100mm Lignacrete blocks 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. No finish, other than paint, is assumed to the blockwork.
Full Cavity Fill and 100mm Lignacrete Blocks
|Cavity fill type||No finish|
U-values (W/m² K)
|100mm DriTherm Cavity Slab 32 Ultimate||0.29|
|125mm DriTherm Cavity Slab 32 Ultimate||0.23|
|150mm DriTherm Cavity Slab 32 Ultimate||0.20|
|100mm Isover CWS 32||0.29|
|125mm Isover CWS 32||0.23|
|150mm Isover CWS 32||0.20|
|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)||0.14|
|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 Therm||0.20|
|125mm Xtratherm Cavity Therm||0.16|
|150mm Xtratherm Cavity Therm||0.14|
Partial Cavity Fill and 100mm Lignacrete Blocks
|Cavity fill type||No finish|
U-values (W/m² K)
|60mm Celotex CW4000||0.27|
|75mm Celotex CW4000||0.23|
|100mm Celotex CW4000||0.18|
|60mm Kingspan Kooltherm K108||0.24|
|75mm Kingspan Kooltherm K108||0.20|
|100mm Kingspan Kooltherm K108||0.16|
|60mm Eurowall Cavity||0.27|
|75mm Eurowall Cavity||0.23|
|100mm Eurowall Cavity||0.18|
|100mm Rockwool Partial Fill||0.29|
|150mm Rockwool Partial Fill||0.20|
|170mm Rockwool Partial Fill||0.18|
|100mm Isover CWS 32||0.27|
|125mm Isover CWS 32||0.22|
|150mm Isover CWS 32||0.19|
(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 because this may vary).
Block Environmental Management and Responsible Sourcing
Our manufacturing plants operate to a BSI certified Environmental Management System (EMS), which complies with ISO 14001.
Lignacite Ltd also meets the requirements of BES 6001 – Framework Standard for the Responsible Sourcing of Construction Products (Certificate No: BES 580823). This independently awarded Responsible Sourcing Certification confirms that we procure products responsibly and sustainably. This will allow credits to be gained under environment assessment schemes such as BREEAM.
Block Energy Management
A BSI certified energy management system in accordance with ISO 50001(Certificate No. ENMS 751020) is used to help manage energy use and includes the following outputs.
- A policy for more efficient use of energy
- Fix targets and objectives to meet the policy
- Use data to better understand and make decisions about energy use
- Measure the results
- Review how well the policy works, and
- Continually improve energy management
Block Environmental Performance Declaration (EPD)
Key environmental performance data (in accordance with EN 15804+A2 and ISO 14025/ ISO 1930) can be found in the EPD for Lignacrete blocks.
Environmental Data Summary
|Declared unit mass||189 kg|
|GWP-fossil, A1-A3 (kgCO2e)||18.2|
|GWP-total, A1-A3 (kgCO2e)||18.5|
|Secondary material, inputs (%)||0.00841|
|Secondary material, outputs (%)||80|
|Total energy use, A1-A3 (kWh)||40.2|
|Total water use, A1-A3 (m3e)||1.33E0|
Source – This data was taken from the EPD for the 7.3N Lignacrete block. Click here for all EPDs.
The declared unit is based on 1m² of 100mm thickness blocks.
The Life Cycle Stage (A1-A3) refers to the extraction, processing, transportation and manufacture of materials and products up to the point where they leave the factory gate to be taken to site.
The notation ‘e’ is an abbreviation for tonnes of carbon dioxide equivalent.
Block Structural Design
The design of walls using Lignacrete Paint Grade blocks should be in accordance with relevant design standards, including BS 8103: Part 2 and BS EN 1996-1-1 and the requirements of the Building Regulations.
Block Movement Control
Vertical movement joints should be considered in accordance with masonry design codes and the recommendations of Published Document PD 6697, at 6.0 - 8.0 metre spacings. In areas of raised stress, such as above and below openings in external walls, the blockwork may need to be reinforced to restrain movement.
Block Service Life
When properly constructed, the durability of walls built using Lignacrete Paint Grade products will match that of walls of traditional masonry and will fulfil their intended function for the life of the building in which they have been installed (typically 100 years).
The blocks themselves will require no maintenance. Maintenance for walls will normally include the replacement of sealant in movement joints and at junctions / openings. Repointing for walls that are exposed to the elements may be necessary towards the end of its service life.
Block Wall Ties
Under normal conditions, wall ties should be embedded 50mm into the mortar on each leaf, staggered in alternate courses and spaced in accordance with the following.
Table 5 – Wall Tie Spacings
|Ties per m²|
|Less than 90mm||50 - 75||450||450||4.9|
|Over 90mm||50 - 150||900||450||2.5|
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 6 – Mortar Mixes
(as per BS 5628-3)
|Compressive Strength Class|
(as per BS EN 1996)
|Recommended mix proportions of materials by volume|
|(iii)||M4||1:1:5 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)||M6||1:½:4-4½ - 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).
Block Surface Finish Recommendations
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
- 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 20kg. 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.
Take a look at our handy downloadable guides, designed to help you get the best from our concrete blocks.
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