Plaza Slab Over Below-Grade Wall

Application of the waterproofing membrane should be considered over all substrate surfaces. Most waterproofing professionals require that the waterproofing membrane cover the entire substrate (most commonly concrete) including the footer. The waterproofing membrane should be fully adhered and applied directly to the substrate with no barrier (insulation) between the membrane and the substrate.

Application of the membrane on a plaza slab that is over a below-grade wall is typically completed in a two-step process. The membrane is applied to the below-grade wall in accordance with the manufacturer’s latest printed requirements. The membrane typically extends up onto the plaza slab and over the control joint.

The waterproofing membrane is then applied over the plaza slab in accordance with the manufacturer’s latest printed specifications. The membrane extends down onto the below-grade wall a minimum of 6 inches, overlapping the below-grade wall waterproofing.

A proper joint sealant should be applied at the control joint prior to the waterproofing membrane application.