I live in the lower flat of a 3-floor house conversion. The front door area of my sub-basement flat hallway, and a storage area under the steps to the main door of the flat above, are gettting wet from rain going through the steps and path to the upper front door. If we put a layer of quarry tiles over the existing ( and damaged) old tiles, how can it be made to stop rain seeping through?
If you are sure the rain is actually going through the concrete as opposed to just over the sides you can lay the tiles on waterproof adhesive and fill the gaps with waterproof grout. Its no different to tiling in the bathroom. See our project on laying floor tiles for help and you can find water proof adhesive and grout in the toolstore on this link
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