1. General technical approval no. Z-17.1-890: Object of approval: Masonry of POROTON plane-ground hollow clay units -T9/-T10/-T11 “DR 34“ in a thin mortar-bed technique. Applicant: Wienerberger GmbH, Oldenburger Allee 26, 30659 Hannover; Schlagmann Baustoffwerke GmbH &Co. KG, Ziegeleistraße 1, 84367 Zeilarn. Berlin: Deutsches Institut für Bautechnik, DIBt, 2012 - Approval number: Z-17.1-890 (05.12); Duration of validity: 31. March 2016.
2. General technical approval no. Z-17.1-1057: Object of approval: Masonry of POROTON plane-ground hollow clay units with integrated insulation - designated as POROTON-T7-MD-plane-ground clay units - in a thin mortar-bed technique. Applicant: Schlagmann Baustoffwerke GmbH &Co. KG, Ziegeleistraße 1, 84367 Zeilarn; Wienerberger GmbH, Oldenburger Allee 26, 30659 Hannover. Berlin: Deutsches Institut für Bautechnik, DIBt, 2011 - Approval number: Z-17.1-1057 (04.11); Duration of validity: 28. April 2016.
3. General technical approval no. Z-17.1-715: Object of approval: Masonry of klimaton plane-ground hollow clay units with interlocking butt joints in a thin mortar-bed technique. Applicant: Klimaton ZIEGEL Interessengemeinschaft e.V., Ziegeleistraße 10, 95145 Oberkotzau. Berlin: Deutsches Institut für Bautechnik, DIBt, 2010 - Approval number: Z-17.1-715 (09.10); Duration of validity: 21. September 2015.
4. DIN V 18580:2007-03 Special masonry mortar.
5. DIN EN 772-16:2011-07 Methods of test for masonry units - Part 16: Determination of dimensions.