Construction

This Standard:

a) establishes a protocol for assessing and determining whether a building has been damaged by concrete blocks containing certain excessive amounts of deleterious materials (free or unbound muscovite mica, or aggregate with potentially deleterious quantities of pyrite),

b) describes methods for establishing the extent of the problem;

c) describes the scope of any testing required; and

d) categorises buildings, in accordance with this Standard, providing competent persons with guidance on the appropriate measures to be taken.

This Irish Standard is not intended for application to:

a) the testing and specification of concrete blocks (aggregate concrete masonry units) manufactured to a harmonised European Standard, I.S. EN 771-3 and guidance provided in a Standard Recommendation, S.R. 325; and

b) buildings not exhibiting structural distress consistent with defective concrete blocks, see Clause 4.

The protocol addresses the issue of defective blocks but does not certify that the dwelling is in other respects free of defect.

The use of this Standard is to be limited to block built dwellings exhibiting signs of distress consistent with damage caused by blocks containing certain deleterious materials. I.S. EN 771-3 is the appropriate standard for production of new concrete masonry units.