Basement Wall Loads?

Hello:
Our one car garage doesn't have floor drains. The garage is attached to the house with foundation walls on all 4 sides of the garage 8 ft. deep with a full basement under the house area. The garage is level with the upstairs, and backfilled with dirt/gravel. I want to install 2 seperate trech drains 14 ft. apart (2 low spots in the floor). and pipe the drains thru the foundation wall to the sewer system. The garage floor is poured on top of the foundation walls 6" thick. Would it disturb the structural integrity if I cut the floor 14 ft. x 1 ft. for the drains and connecting pipes? The garage is a 26 ft. x 14 ft. This would be 2.5 ft. away from the wall parallel to the 26 ft. length. I think the concrete has 6 in. x 6 in. welded wire.

 

[dik]

This shouldn't pose a problem, but you should discuss it with a good local contractor. Anytime you 'mess' with an existing condition you can develop cracking, etc. A 6" slab seems thick for our area (generally 4&quot. You might want to confirm that the slab is just a slab on grade.

If I understand the problem, you have a 14'x26' slab and you want to install 2 trench drains 1'wide by 14' long. I assume that the length of the trench drain if full width of the 14' dimension. The one trench drain will be located within 2'6 of the one wall and the trench drains are perpendicular to the 26' wall separated the basement from the garage. The other 3 walls are backfilled on each side.

The slab should be chipped away carefully so that the WWM is not damaged. The trench drains should be about 3' wide at the top and 2' wide at the bottom with the underside of the sides sloping at 45 deg. approx. This should be reinforced with light rebar and the WWM lapped with it to provide some continuity.

The length of the trench drain should be shortened to 12' to allow concrete and reinforcing to be placed at each end.

If you can relocate the one trench drain to increase the 2'6 distance to something like 4' to move it further from the outside wall.

 

Thanks dik for your help.

The floor has 2 low spots 14 ft. apart. That is why I need to have the drain at 2 locations. The 14 ft is along the 26 ft. wall. See example below. I did check and the slab is poured on top of the foundation wall agenst the 1st floor joist, and is 6" thick. The slab is poured on backfill dirt and 3 to 6 in. of large gravel. Cannot verify the compaction of the backfill!! I was going to cut the concrete and install a pvc trench drain and pour concrete back around it. I didn't know if this would be ok to cut the concrete?


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[ishvaaag]

On my opinion if as I understand you have a slab "on the ground" (i.e., supported in the wohole surface) 6 inch thick and reinforced with a mesh you cam machine such cut, then do the work itself without much problem; you may want to keep the mesh even disturbed to join later your new concrete.