Red Seal Tilesetter Practice Exam

What should be done to tiles before applying grout?

1. Wash them with soap

2. Seal them with a protective layer

3. Ensure they are completely dry

4. Fill in any cracks

The correct answer is: Ensure they are completely dry

Before applying grout, ensuring that the tiles are completely dry is crucial. This step is important because moisture trapped under or in the tile can lead to poor adhesion of the grout and can even cause issues with mold or mildew if water gets trapped. Additionally, if the tiles are wet, grout application can result in uneven cure times and may lead to a compromised grout joint, which might weaken the overall integrity of the tiled surface. While the other options suggest various preparations, they do not address the primary concern of moisture that could compromise the effectiveness of the grout. Washing tiles with soap or sealing them may be valid procedures in certain contexts but do not relate directly to the immediate need for dryness before grouting. Filling in cracks, on the other hand, pertains more to the condition of the tiles themselves rather than preparation for grouting, which specifically requires tiles to be dry for optimal results.