As a result Allco Waterproofing Solutions have received many phone calls and emails from NZIA members who were present.

The seminar raised a number of questions relating to how bentonite performs in below grade conditions and, for Allco, highlights the importance of the quality assurance process and standards we have developed around the Volclay Waterproofing System.

The main question the company has been asked is “do drying conditions cause shrinkage and failure by cracking which does not heal reliably on rewetting?”

The Volclay Waterproofing membrane does not suffer from drying conditions causing shrinkage.  The Volclay System when hydrated and confined cannot dry out when below grade. It will not crack or deactivate. (Please see the Technical Reference Document 203 explaining bentonite Waterproofing and wet/dry cycling)

Further, Volclay Bentonite systems are BRANZ appraised to the NZ Building Code. During this appraisal of Volclay, testing wet/dry cycling, BRANZ confirmed that this does not occur in Volclay Bentonite.

In fact it took BRANZ three days using an industrial oven set at over 200^oc to remove the moisture from a hydrated sample of Volclay Bentonite and return it to a granular state.

Volclay also conforms to the ASTM International standard in the USA and has held a BBA UK approval since 1986.

Allco heartily agree with Bill Grayson’s closing comments at the seminar: "Don’t test the product - control the process".  This is one of the reasons for the Allco Volclay Quality Assurance service:

http://youtu.be/omtdDl_bfdg