Masterseal 340F 

Masterseal 340F is a sprayable membrane for waterproofing concrete structures.  Masterseal 340F is spray applied in a sandwich between layers of sprayed or cast concrete.  It has excellent bond strength characteristics to the substrates on both sides of the membrane (about 1.0 N/mm2) and good elasticity.

Masterseal 340F is a water-based dispersion with no hazardous components, making it safe to handle and apply in confined areas.

As an air-cured system, Masterseal 340F typically needs between one and three days for drying out.  Drying out time is dependent on the following:

• Air temperature (ideal working range between 5ºC and 30ºC)
• Air humidity (optimal below 80% RH)
• Ventilation (optimal with more than 5 m/s)
• Layer thickness (optimal to apply approximately 1mm for the first coat applied followed by 2mm thick coats)

As with all spray applied products, it is not possible to seal against active water ingress through the substrate.  In such cases the Masterseal DR1 drainage system is recommended to be used in combination with Masterseal 340F.  Please refer to Masterseal DR1 technical data sheet for details.  Steel fibre reinforced sprayed concrete can be used on both sides of the Masterseal 340F membrane.

Masterseal 340F is recommended for:

• sprayed concrete structures
• replacement of PVC sheet membranes in sandwich structures (concrete/membrane/concrete)
•  single shell permanent tunnel linings constructed of sprayed concrete
• ideal for complex tunnel geometries where PVC membranes are limited
• waterproofing underground structures with rock anchor/bolt heads and irregular excavation profiles