WAJD Learning

On site trade skills · Beginner to competent DIY

Tiling that does not crack or leak

Deflection, tanking and movement joints: the three things that decide whether tiling lasts.

  • 2modules
  • 2.5CPD hours
  • 90guided minutes
  • Freealways

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About this course

Tiling looks like a setting out and neatness job and fails as an engineering one. Tiles are rigid brittle plates stuck to things that move, in rooms full of water.

This course covers the three things that actually decide whether tiling lasts: floor deflection, tanking wet areas properly, and movement joints. It is blunt about the most misunderstood fact in domestic tiling, which is that a tiled shower is not waterproof and never was.

What you will be able to do

  • Assess a substrate for flatness, stability and deflection
  • Tank a shower or wet room correctly, including corners and penetrations
  • Choose adhesive and grout appropriate to the substrate and the situation
  • Place movement joints and use silicone where grout would crack

Modules

  1. 1 Substrates, deflection and tanking a wet area 45 min study · 4 min script · 4 question knowledge check
  2. 2 Setting out, cutting and grouting 45 min study · 4 min script · 4 question knowledge check

Assessment and certificate

A knowledge check and a final assessment at 80 per cent, unlimited attempts.

A free digital certificate with a verification code. Knowledge only, not a trade qualification.

Questions

Is a tiled shower waterproof?

No. Tiles are impervious but grout and the adhesive bed are not. Water passes through grout lines steadily. Waterproofing comes from a tanking membrane applied to the substrate before tiling, with taped corners and sealed pipe penetrations.

Why does the grout keep cracking in the corner of my bathroom?

Because it was grouted rather than siliconed. Grout is rigid and the two planes move relative to each other. Every internal corner and change of plane needs a flexible sealant.

Can I tile straight onto a chipboard floor?

Not directly. Chipboard moves with moisture and deflects. Overboard with a purpose made tile backer board, or use an uncoupling membrane, and fix the deflection first if the floor moves underfoot.