Module 1: Advanced Surface Preparation
Proper surface preparation is the foundation of a successful tiling project. A poorly prepared substrate can lead to cracked tiles, adhesive failure, and water damage. This module covers critical steps to ensure surfaces are stable, level, and ready for tiling.
1. Assessing Substrate Conditions
Before tiling, the substrate (the surface receiving tiles) must be inspected for:
Structural Integrity: Ensure concrete, plasterboard (drywall), or plywood is solid, without rot, cracks, or movement.
Flatness & Level: Use a straightedge or laser level to check for dips, humps, or slopes exceeding 3mm over 1m.
Moisture Content: Concrete slabs must be fully cured (typically 28 days); wood substrates should have <12% moisture.
Cleanliness: Remove dust, grease, old adhesive, or loose particles that could weaken bond strength.
2. Correcting Uneven Surfaces
Imperfections must be addressed to prevent lippage (uneven tile edges) and adhesion issues.
Self-Leveling Compounds (SLC): Used for floors with minor undulations. They flow smoothly and create a flat surface.
Prime the substrate first to ensure proper bonding.
Mix and pour SLC, spreading with a gauge rake.
Patching Compounds: For deeper holes or cracks in concrete or plaster.
Use a cement-based patching mortar for concrete.
For drywall, apply a setting-type joint compound.
Sanding/Scraping: High spots can be ground down with a floor grinder or sanded smooth.
3. Waterproofing Wet Areas
Wet areas (showers, bathrooms, kitchens) require moisture barriers to prevent leaks and mold.
Shower Tanks (Waterproof Membranes):
Liquid-applied membranes (e.g., Ardex WPM, Mapei Aqua Defense) are rolled or brushed on.
Sheet membranes (e.g., Schluter Kerdi) are adhered to walls/floors.
Sealing Joints & Corners: Use waterproof tape on seams and corners before applying membrane.
Testing for Leaks: After waterproofing, perform a flood test (for floors) to ensure no water penetrates.
4. Primers & Bonding Agents
Different substrates require specific primers to enhance adhesion:
Concrete & Cement Boards: Acrylic or epoxy primers improve bond strength.
Plasterboard (Drywall): Use a universal primer to prevent moisture absorption.
Plywood: A flexible, high-bond primer prevents movement-related cracking.
Painted Surfaces: Lightly sand and apply a bonding primer to ensure tiles stick securely.
Practical Task: Prepare a Mock Wall/Floor with Imperfections
Step 1: Create a mock substrate (e.g., plywood with holes, uneven concrete board).
Step 2: Assess and mark problem areas (low spots, cracks).
Step 3: Apply patching compound to deep voids and level with SLC where needed.
Step 4: Waterproof a designated "shower area" using a liquid membrane.
Step 5: Prime the entire surface appropriately before proceeding to tile installation.
Key Takeaway:
A flawless tile installation starts with meticulous surface prep. Skipping steps can lead to costly failures, making this module essential for professional results.
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