Concrete – How to cut grooves in self-leveling concrete to incorporate an existing drain


This is a follow up question to my previous question about leveling a basement floor without losing the drainage. After the feedback I decided to use self-leveling concrete and cut (or form it in advance) grooves (canals?) that lead to the existing drain.

I just found that I received an answer with the same idea. But I'd like to elaborate more. For example:

Is it necessary to redo the drain or can I just leave it lower, perhaps by just adding another grill on top?

Can I use forms, for example pieces of wood that go all directions (like rays) from the drain?

Or is the best idea to use a screw driver like Justin Kuhs suggests in his answer to me? (BTW, Justin, thanks a lot for your answer, I didn't think of the screw driver at all, great idea!)

Have people here done such things? What were your experiences?

Best Answer

24 sq ft would be an area approximately 4x6? Adding two inches of depth... I think what I would try in this case would be to get several 1/2" dowel rods and cut them to lengths that would allow me to align them in a radial pattern out from the drain, something like this:

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Around the drain, I would prop them 1.5" up in the air, and at the periphery I'd prop them 2" up in the air, that way when I poured, I'd end up with 1/2" deep semi-circular troughs that ran downhill towards the drain. Pour concrete, let it set up and remove the dowels.

DEFINITELY add a new drain cap on top of the old one as a 3" diameter 2" deep hole in the floor is a serious trip hazard.