We currently have a building underway and it's foundation consists of individual concrete footings extending 3m (~10 ft) below ground. It's also worth noting that the structure does not have a basement.
I thought it would be a good idea to install a subsurface drain (e.g. French drain) around the building as a safety/preventative measure. However, it seems to me that maintaining and replenishing a subsurface drain drain at the depth of the footings (3 m / ~10 ft) would be quite impractical and costly. Also, the sump into which it drains would be equally deep and hard to maintain.
What are my options in this scenario?
- Do foundations as deep as mine usually implement subsurface drainage?
- Is a subsurface drain even worth having in my scenario? (Recall there is no basement.)
- Should I split the difference and install the drain at a shallower depth above the footings?
Best Answer
It sounds like you are using a pier foundation. Piers should be deep enough that they are hitting undisturbed, solid soil or bedrock. As such, there's likely little reason to have a french drain in that situation as the footings should be well below the depth that would be effected greatly by surface water.