Foundation drain for Thickened Slab Building?

[GRANITE80]

I'm doing some work for a non-profit's new 900 square foot building. The foundation is a thickened slab. In our typical commercial work, I would always call out for a foundation drain around the perimeter of the thickened floor edge. However, is it really necessary for such a small structure? The building is up "high" and the ground is fairly permeable, so ground water should pass right through...

Any thoughts please... trying to save this non-profit some $$$.

 

[JAE]

What is the purpose of the foundation drain in the first place? I'm not sure you need such a thing. Usually foundation drains are used to minimize lateral earth pressure on basement walls.

 

[dik]

It minimises water for heaving conditions and helps with the PEVB beneath the slab. If it's located on a high spot and depending on the soil, it may be a simple matter of venting the perimeter drain to the side of the hill and adding some stone to reduce erosion if water's a problem.

Dik

 

[apsix]

A perimeter drain is not normal practice in my experience. Therefore, based on that experience, I would say it is not necessary, unless there are particular, site specific, reasons for it.