frost wall drainage help please

[Mungo Park]

I am installing a frost wall, the frost wall is to be 16" deep and 36" out, sloping down slightly. The garage plan is 16X22'.
Do I need to cover this up with something other than the dirt I dig out?
Is their something to put down to aid drainage, would a layer of gravel or quater down (sp) or something like that be better.
I am thinking since it is all dug up adding something would be easy, sort of make it like a french wall or something, like that at the edge of the insulation.
Cheers Ron.

 

[rinny_tin_tin]

I am installing a frost wall, the frost wall is to be 16" deep and 36" out, sloping down slightly. The garage plan is 16X22'.
Do I need to cover this up with something other than the dirt I dig out?
Is their something to put down to aid drainage, would a layer of gravel or quater down (sp) or something like that be better.
I am thinking since it is all dug up adding something would be easy, sort of make it like a french wall or something, like that at the edge of the insulation.
Cheers Ron.

16 inches sounds too shallow especially for your area. Here in Virginia its 18 inches minimum. You can cover with excavated dirt; however, No 54 gravel is better. If you have drainage concerns - use 4 inch drainage pipe at base sloped 1/4 bubble with 54 gravel on top all way to grade. If you want dirt on top of gravel (e.g., plantings, etc) put a layer of landscape paper on top of gravel and about 1 foot down. I would guess that you should have at least 2 or three feet below grade for your footer - and I would go with three feet.

 

[Mungo Park]

Thank you for your help, I will re check my insulation depth again, I coulsd easily be wrong, but worth checking, want to be right.
Cheers Ron.

 

[Mungo Park]

Thanks for pointing this out, 30" down, i guess my brain was in denial.
Cheers Ron.