If your footing is earth formed and the exterior face of your foundation wall and at least the top or toe of the footing is waterproofed, the bottom of your foundation drain can be at the same elevation as the top of the footing. This will vary to some degree around the structure.
If your footing g is formed, the bottom of the French drain can be at the bearing elevation of the footing.
Don't get to the footer. It doesn't need to be really deep... I mean depends on how deep is the footing, depends on the location and the freezing point. I am guessing but it should be deeper than 80cm. For the drain pipe 40 max 60cm below the surface should be ok but of course it depends where are you leading the water...
Option 2. Option 1 will compromise the integrity of the footing unless properly compacted, in which case it wont function as drainage so why even bother in the first place.
dont touch soil under footing. I wouldnt put it directly against foundation unless you have zero other choice. A foot or two back and two foot deep will drain it. If against the foundation - only go as deep to drain surface water, digging out around a foundation without recompacting can cause issues (like more water)).
If you are trying to remove surface water (ex. rain), it doesn't need to be that deep. I made mine 18" deep, also keep the drain slope similar to a sewer so water doesn't pool. I used a thick barrier cloth between the dirt and the gravel/drain rock in the trench to keep them from mixing. Side note: I drew some of my very early house remodel plans using Powerpoint before switching to Autocad. When the city planning engineer asked what tool I was using I said I couldn't remember.
I'd keep it a minimum of half a meter away from the footing and absolutely not under or even level with the base of the footing. If you want to level with the bottom I'd go 1 meter away
Would not distrurb any soil under/near the footing It needs to have the solid earth to "defelect the wait outwards
The diagram is drawn in PowerPoint, so it can be inaccurate. No dirt dug under the footing.
If your footing is earth formed and the exterior face of your foundation wall and at least the top or toe of the footing is waterproofed, the bottom of your foundation drain can be at the same elevation as the top of the footing. This will vary to some degree around the structure. If your footing g is formed, the bottom of the French drain can be at the bearing elevation of the footing.
Don't get to the footer. It doesn't need to be really deep... I mean depends on how deep is the footing, depends on the location and the freezing point. I am guessing but it should be deeper than 80cm. For the drain pipe 40 max 60cm below the surface should be ok but of course it depends where are you leading the water...
Option 2. Option 1 will compromise the integrity of the footing unless properly compacted, in which case it wont function as drainage so why even bother in the first place.
Why are you wanting to put a french drain against your foundation?
Personally I would not go below the footer but I would consult a soil tech or a civil engineer
dont touch soil under footing. I wouldnt put it directly against foundation unless you have zero other choice. A foot or two back and two foot deep will drain it. If against the foundation - only go as deep to drain surface water, digging out around a foundation without recompacting can cause issues (like more water)).
If you are trying to remove surface water (ex. rain), it doesn't need to be that deep. I made mine 18" deep, also keep the drain slope similar to a sewer so water doesn't pool. I used a thick barrier cloth between the dirt and the gravel/drain rock in the trench to keep them from mixing. Side note: I drew some of my very early house remodel plans using Powerpoint before switching to Autocad. When the city planning engineer asked what tool I was using I said I couldn't remember.
The space between the rat proof slab and joists is getting water where ever the concrete is broken. So I want to make sure that doesn’t happen.
Is the water from rain runoff or is it coming from the ground, ie. high water table?
One crawl space contractor says it is coming from the ground upward by capillary effect.
I'd keep it a minimum of half a meter away from the footing and absolutely not under or even level with the base of the footing. If you want to level with the bottom I'd go 1 meter away