The space between the shower pan and cement board should be 1/8 inch. This is to ensure water does not leak out of the shower, which could cause damage to walls or floors.
Here are some tips for measuring this space:
- Use a ruler or tape measure to accurately assess the gap size.
- Place shims in areas where one side is higher than the other if necessary.
- Check that all corners line up with each other, as any unevenness will lead to water leakage.