SUBSTRATE QUALITY
All substrates must be cleaned and prepared using high pressure water jet. Abrasive blast cleaning, scarifying equipment to or other suitable approved mechanical methods.
Cementitious substrates:
Concrete should be cured for at least 28 days and should have a pull-off strength > 1.5 N/mm2. Loose friable material and weak concrete must be completely removed by mechanical means to achieve an open textured surface and all surface defects such as blowholes and voids must be fully exposed. Repairs to the substrate, filling of joints, blowholes/voids and surface leveling must be carried out using the appropriate Sika® products. Refer to Sika’s Technical Department for further advice. High spots must be removed by for example grinding.
Outgassing is a naturally occurring phenomenon of concrete that can produce pinholes in subsequently applied coatings. The concrete must be carefully assessed for air entrapment, and surface finish prior to any coating work. Installing the Sikalastic®-311 (AE) either when the concrete temperature is falling or stable can reduce outgassing.
Prime the substrate before applying the Sikalastic®-311 (AE) systems.
Brick and stone:
Mortar joints must be sound and flush pointed.
Bituminous felt:
Ensure that Bituminous felt is firmly adhered or mechanically fixed to the substrate.
Bituminous felt should not contain any badly degraded areas and be primed before applying Sikalastic®-311 (AE).
Metals:
Metals must be in a clean sound rust free condition. Metals surfaces must be free of oil and greases. Abrade exposed surfaces to reveal bright metal and primed with Sikalastic® Metal Primer.
Paints/Coatings:
Ensure that the existing material is sound and firmly adhered. Remove any oxidized layers.
Please note: Always apply a test area first