Concrete Block Association
</font></font> <h1> <font size="4" face="Verdana, Arial, Helvetica, sans-serif"><span class="style12">Aggregate Concrete Block meets Part E. <br> The Concrete Block Association </span></font></h1> <h3> <strong>The CBA </strong> provides information on <strong>Building regulations</strong> covering <strong>Part E</strong>, <strong>Part L</strong>, <strong>Part J</strong>, <strong>U-Value, </strong><strong>U-Values<br> </strong>and <strong>Robust details</strong> &amp; <strong>aggregate concrete blocks</strong>. <strong>Concrete blocks</strong> can be used for <strong>self build</strong>. <strong>Building houses</strong>, <strong><br> building extensions</strong>, <strong>building walls</strong> and <strong>building foundations</strong>. <strong>Concrete blocks</strong> come in different weights: <strong><br> dense blocks</strong> and <strong>lightweight blocks</strong>. Competitors include: <strong>timberframe</strong>, <strong>aircrete</strong>, <strong>breezeblock</strong>, <strong>celcon</strong>, <strong><br> thermalite</strong> and <strong>bricks</strong>. Masonry units</h3> <font face="Verdana, Arial, Helvetica, sans-serif"><font size="4">
Memebers Technical Information Enquiries Members

     
 

Frequently Asked Questions


CBA members receive hundreds of calls from specifiers and users of their products. Enquiries are often of a similar nature and the CBA have compiled answers to the most common questions.

 

Q1.

What is the current British Standard for aggregate blocks?

A.

BS EN 771-3 which covers the BS requirements of all types of concrete block (and brick) units. Other relevant masonry standards include BS 8103-2, PD 6697, BS EN 1996-1-1, BS EN 1996-1-2and BS EN 1996-2. BS 6073-2 gives guidance on the selection of masonry units.

 

Q2.

What is the thermal performance (U-value) of a wall incorporating aggregate blocks?

A.

This depends on the type and thickness of materials used to construct the wall, including and airspaces. For convenience refer to CBA members for advice. This depends on the type and thickness of materials used to construct the wall, including any airspaces. Refer to CBA datasheet 8 or CBA members for more detailed advice.

 

Q3.

What type of mortar mix should be used to lay aggregate blocks?

A.

Careful selection of mortar is essential. Extensive guidance is given in the BS 5628 suite of masonry design standards. The location of the blockwork is an important consideration, and as a guide stronger mortars will be required in high exposure situations. Similarly the design of walls employing high strength blocks, typically 10.4N/mm or greater, will resulting enhanced loadbearing capacity when designation (ii) (M6) or (i) (M12) mortar mixes are used. However, for the construction of most internal walls in inner leaves of cavity walls above ground, it is common practice to specify mortars no stronger than 1:1:6 cement, lime, sand composition or similar designation (iii) (M4) mix.

 

Q4.

What products can be used in party wall construction to meet the sound insulation requirements of building regulations

A.

Aggregate blocks can be used to construct solid and cavity separating walls combining plaster or drylined finishes. For solid walls dense solid blocks are advocated to construct 215mm walls (100mm blocks laid flat). For cavity walls 100mm thickness lightweight or dense aggregate blocks can be used depending on cavity width and type of surface finish. Aggregate blocks also feature many of Robust Standard Details. These constructions can be used in a new dwellings without the need for routine pre-completion testing. See CBA data 7 or contact CBA members for specification details.

 

Q5.

At what intervals are movement joints required to be provided in aggregate blockwork?

A.

Vertical movement joints should be considered at about 6 to 9 metre intervals, depending on block type, but their inclusion is not normally required in internal walls in dwellings. Special attention should be given to low height panels and areas of high stress concentration. Guidance is given in BS 5628: Part 3, CBA data sheet 12 or consult CBA member's literature.

 

Q6.

What is the life expectancy of aggregate blockwork?

A. Blockwork is normally assumed to have a service of 60 years, but in practice it is known to last considerably longer.
 

Q7.

Which products are recommended for direct painting in an industrial environment

A. Most CBA members can provide a close textured/paint grade aggregate block suitable for direct painting. These products are very robust and provide good resistance to impact damage
 

Q8.

Which products can be used below ground?

A. All types of aggregate block are suitable for use to the inner leaf of external cavity walls, or internal walls below ground. For the external leaf of external cavity walls, or solid external walls, dense, lightweight 7.3/mm2 blocks or aggregate blocks with a density of at least 1500kg/m3 are all suitable. Where unusual ground conditions exist, or for more information, please contact CBA members for advice or see CBA data sheet 3 on sulphate solids.  See CBA datasheet 4.
  

Q9.

What products are suitable for use as infill units in beam and block flooring?

A. A number of products can be used depending on design requirements. these include dense and lightweight aggregate blocks 7.3N/mm2 (solid & cellular), or 3.6N/mm2 (flooring grade). Generally 100mm thickness blocks are used.
  
Q10.What thickness of block is required for a non-loadbearing partition?
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