My sister has what appears to be a failed footing drain and asked me to repair it. I’m not sure what I’ll find when I excavate since this place was built in the 70’s. I’ve done some research and have a fairly good idea what I need to do for replacement. Here’s what I have in mind and feel free to correct any errors.
I’ll place 2-3″ of 3/4″ stone at the bottom of the trench. I’m thinking the trench should be about 20″ wide. Then 4″ pipe covered by another 2-3″ of stone. The top of the drain pipe will be level with the top of the footer. I’ll cover the pipe with a pipe sock along with a similar fabric on top of the last layer of stone before backfill. I’m still not sure which drain pipe is better though, the white ABS with holes in the lower section or the black with slots all the way around, or does it matter?
What I’m most concerned about is supporting the 6′ trench walls while the work is in progress. About 30′ will have to be dug by hand since there is no room to get a machine in there and I don’t want to chance damaging the basement wall. The remaining 100′ or so to reach a daylight exit will be dug with a backhoe. Do I need to shore up the trench walls or is 6′ shallow enough to support itself?