QUESTIONI have ground water seeping through my tile grout. It has been suggested to me to have French drains installed around the permitter of the house. I would appreciate very much your opinion on the efficacy of this as a remedy. It is hard for me to understand how the drains would remove the water from under the house. Thank you very much.
ANSWERANSWER - If in fact you have ground water migrating up through your concrete slab and up through the porous tile grout joints, installing French drains around the perimeter of your house could divert the water from migrating up through the concrete slab.
If the water is coming from a high water table, the French Drains might not work well depending on how they are constructed and whether you have a vapor retarder membrane under the concrete slab or not. If the water is coming from the planters or a hillside the french drains should allow the water to drain away if constructed correctly.
French Drains are where they install a perforated plastic drain pipe about 4" in diameter or more in the ground. Rocks are placed under, around and on top of the perforated pipe. The pipe is covered with a cloth to filter out dirt and to keep roots from going inside the pipe and blocking it. So as water travels towards the house it readily drains into the gravel and into the drain pipe where it is diverted to the storm drains.
If the water is coming from a higher level or from the high water table it could be causing a hydrostatic condition. That means the water could be applying a force that can cause the tile to come loose. In some cases a French drain will mitigate the problem and sometimes you have to have a sump pump incorporated to keep a high volume of water diverted.