Dáil Éireann Debate, Tuesday - 18 September 2012
1111. Deputy Joe Higgins asked the Minister for the Environment; Community and Local Government , noting the Pyrite Panel report, his views on whether the stone fill being sold by quarries in counties Dublin, Meath, Kildare and Offaly for use under ground floor slabs to houses and extensions is fit for purpose and will not cause heave; and the test results he has available to support this conclusion. [38947/12]
Amharc ar fhreagraStandard Recommendation (SR) 21:2004+A1:2007 provides specific guidance on reducing the risk of reactive forms of pyrite being present in hardcore material for use under concrete floors in dwellings and buildings. It sets an example specification for unbound granular fill for use under concrete floors and paths. The example specification sets out verifiable performance criteria for hardcore. It sets the quality of the aggregate (attempting to rule out low quality stone), the grading (reducing the level of fines) and the results required from sulfur-related chemical tests.
Clause 3.4.2 in SR21 sets out the guidance to be followed in relation to the total sulfur results:
- if the result is less than 0.1%, no further testing is required, unless there is a significant change in the quarry deposit;
- if the result is between 0.1 and 1%, there is a risk of swelling from pyrite, and it is advised that a suitably experienced petrographer carry out a detailed mineralogical examination to establish:
(a) the material’s suitability as hardcore under floors and footpaths, and
(b) an appropriate testing frequency for total sulfur based on the variability of the quarry deposit.
In view of the expertise and knowledge that has been developed in the past five years, the Pyrite Panel recommended that the existing guidance should be reviewed to see if it can be further developed. In addition, the Panel recommended that a testing, certification and traceability system should be put be put in place for quarries. I have asked the National Standards Authority of Ireland (NSAI) to undertake this work. The onus is on the builder/developer to ensure that all works undertaken are compliant with the relevant parts of the Building Regulations.
