3 Must Haves for Waterproofers

Sika has an extensive range of Acrylic, Bituminous Acrylic, Polyurethane Dispersion, Polyurethane and Cementitious waterproofing membranes. These products have unique qualities and performance characteristics which make them well suited to a variety of waterproofing applications.

• Always consult the current Technical Data Sheet to ensure you have the correct information prior to beginning any waterproofing application.
• The Building Code of Australia and the Building Services Authorities in each state require that Wet Area Waterproofing ie Domestic and Commercial Bathrooms, Shower Recesses and other applicable Wet Area waterproofing is undertaken only by a licensed / experienced and approved contractors.
• There are numerous waterproofing membranes available from Sika and each one has unique characteristics which makes it suited to a particular criteria in waterproofing membrane application. Obtain all of the relevant information regarding your customer’s requirements prior to selecting a solution. If in doubt, consult Sika.
• Always handle, prepare and apply the waterproof membrane in strict accordance with the information supplied on the Product Data Sheet and also the Safety Data Sheet as some of the products are hazardous and require care in handling and applying.
• Many variations exist on site that can reduce the effectiveness of the application of waterproofing membranes. Evaluate the site and prevailing conditions prior to beginning the application.
  
• Care should be taken to inspect and assess substrate conditions, prevailing weather conditions, likely conditions immediately after application and for the subsequent 4 – 6 hours.
• Always use the indicated priming system as this will offer numerous benefits over not using one.
• A thorough assessment of the substrate, site conditions etc. will reduce greatly any likelihood of issues with the application.
• Always observe inter-coat times as applying a subsequent coat over an incomplete cured previous coat can greatly affect the performance of the membrane and the time it takes to completely cure.
• When using a brush or roller to apply the membrane it is good practice to apply the subsequent coats at 90 degrees to the previous coat to ensure an even film thickness is achieved.
  
• Never apply a membrane in direct sunlight or when the air or surface temperature is rising. Always apply the membrane with a stable or falling temperature to ensure air bubbles are avoided.
• Ensure good ventilation and air circulation around the application to ensure drying efficiency. Generally a fan is adequate to provide circulation.
• Cool dry conditions will slow the cure times of primers and membranes (longer curing times)
• Hot dry conditions will accelerate the cure times and reduce inter-coat periods.
• Hot and humid conditions can slow the cure time of priers and membranes of water based membranes.

• Bubbling or Blistering can be a common fault in waterproof membrane applications. Generally this is due to moisture in the substrate or an application when the air temperature or the substrate temperature was rising.
• Sticky or tacky surface after the membrane application is usually caused by the application of the second and subsequent coatings prior to the previous coat being adequately dry.
• Adhesion loss - the membrane is not adhered to the substrate firmly. This is generally a priming issue (not primed) or a surface incompatibility resulting from treatments applied to the surface previously. ie Curing Compounds, Oil, Grease, Silicones etc. A lack of adhesion is not a membrane fault or failure. It is likely to be a lack of surface prep or an incompatible surface to which the membrane was applied.
• Water bubbles under coatings. This is generally due to moisture coming up through substrate from the non-membraned side and further evaluation is required to stop this moisture.
• Membrane splits or tears. Generally a movement crack is evident directly below the torn membrane. The crack will need to be repaired and secured before reapplying membrane coating.
• Membrane tears in corners at right angle joints – a fillet sealant to avoid 90deg angles is required. Use of Sika Fabric is recommended to allow for movement of the floor/wall junction
• Membrane deteriorates and cracks prematurely. Check that the membrane is UV stable. Below grade suitable membranes cannot be used in exposed applications.
• Moisture appears evident on the other side of where a waterproof membrane is applied. This will be caused by an interruption in the membrane coating. Always ensure that any penetrations are well sealed prior to waterproofing also as a waterproofing membrane will retain it’s water proof integrity if correctly applied.