SUBSTRATE PREPARATION
IMPORTANT
Reduced service life due to incorrect treatment of cracks
The incorrect assessment and treatment of cracks may lead to a reduced service life and reflective cracking.
- For static cracks, ensure the width is suitable for overcoating with Sikafloor®-2640.
- For dynamic cracks, ensure the movement is within the movement capacity of Sikafloor®-2640.
TREATMENT OF JOINTS AND CRACKS
Construction joints and existing static surface cracks in substrate require pre-treating before full layer application. Use Sikadur® or Sikafloor® resins.
SUBSTRATE CONDITION
Cementitious substrates must be structurally sound and of sufficient compressive strength (minimum 25 N/mm2) with a minimum tensile strength of 1.5 N/mm2.
Substrates must be clean, dry and free of contaminants such as dirt, oil, grease, coatings, laitance, surface treatments and loose friable material.
MECHANICAL SUBSTRATE PREPARATION
IMPORTANT
Surface defects due to voids in the substrate
Voids and blow holes in the substrate will weaken the surface and damage the covering Product if not repaired during the preparation process.
- Fully expose blow holes and voids during surface preparation to identify the required repairs.
- Remove weak cementitious substrates.
- Prepare cementitious substrates mechanically using abrasive blast cleaning, abrasive planing or scarifying equipment to remove cement laitance.
- Where thin layer resins are going to be applied, remove high spots by grinding.
- Remove all dust, loose and friable material from the application surface with industrial vacuuming equipment.
- Level the surface or fill cracks, blow holes and voids with products from the Sikafloor®, Sikadur® and Sikagard® range of materials.
For additional information on products for levelling and repairing defects, contact Sika® Technical Services.
SUBSTRATE PREPARATION OF NON-CEMENTITIOUS SUBSTRATES
For information on substrate preparation of non-cementitious substrates, contact Sika® Technical Services.