Basements Waterproofing From the Negative Side :application Procedure(1st Part)

 SURFACE PREPARATION

 

 Cementitious waterproofing products need a thorough preparation of the substrate and this is a serious drawback for these materials.

 

The surface - most usually concrete - must be structurally sound and clean.

 

Traces from dirt, formwork release agents, oils, efflorescence and other contaminants should be removed.

 

Laitance on the floors is a serious trap. It should be thoroughly removed by high pressure water blasting, abrasion blasting or a combination of both.

 

The final surface should be absorptive (having open pores).

 

Cracks, concrete honeycombs, bolt holes, construction joints etc. must be adequately cut out and filled with a high strength, non shrinking, waterproof, repair mortar.

 

 Take care: The walls of the repair should be cut vertical or better in the shape of inverted V. This is critical for the right anchorage of the mortar.

 

All joints and cracks should be cut into at least a 2x2cm section and all holes to a 3x3x2cm opening.

 

 

PRE-WATERPROOFING

 

 In the case of active water leaks a quite demanding pre-waterproofing procedure should be followed.