Will French Drains around my house stop Ground Water from Seeping through My Tile Grout?


I 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.


ANSWER - 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.

2 thoughts on “Will French Drains around my house stop Ground Water from Seeping through My Tile Grout?

  1. Erualdo says:

    Hi. the back of my back unit (previously a garage) is backfilled four feet deep because the first four feet are cinder block. The entire back perimeter is a dirt walkway. I’ve excavated 4 dt deep and two feet wide to waterproof. Before backfilling and making the walkway cement, should I place french drains at the footer? I plan to put in a slight V-shaped cement walkway with some drains in the middle. Water did intrude some months ago this is why I am now doing this project and trying to do it right. Thanks!

    • Donato Pompo says:

      If I understand you correctly, you are only trying to waterproof and construct a concrete pad for the 2 foot wide walkway along the perimeter of where you garage was located. You said you excavated 4 dt deep. I doubt that you meant 4 feet deep, or that the dt is a unit for displacement ton, but I don’t know what you mean by dt means in terms of depth.

      Assuming you don’t have a high water table, I would first compact the ground, and then put a gravel base down of at least 4″ and compact it. You could put trenches to the side with perforated drainage pipe to divert any water away. You then can place your concrete with rebar reinforcement suspended in the concrete the the lower 1/3 height of the concrete, which I assume you will put down at least 4″ thickness of concrete if it is only used as a walkway or thicker if it will be subjected to heavier loads. You can slope the driveway so water drains off to the side into the trench drains or you can put area drains in the sidewalk, which normally wouldn’t be done for such a narrow application. You can put a trench drain at the lower end of the walkway.

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