Which concrete should be used?

[xelirator]

Hi.. I have a hole in my pump room that I was thinking of filling in since the inspector pointed it out.. What do you think I should use? I'm a novice at concrete/self-leveling compound..

 

[Östlund]

Use regular coarse concrete.
If you want, you can use the last 5-10cm with something finer like self-leveling compound to get a smoother surface.

 

[xelirator]

I understood that.. Thank you for the answer take care!

 

[Östlund]

If you want to be really serious, you can cast a curb around the pipes afterwards.
Then you can cover it with tiles

If the hole is deep, you can fill the bottom with something like styrofoam. No need to cast a slab of 50cm