Stumps under slab

[Pops15]

It's a no brainer....Take out the stumps and as much of the root system as you can. Place and compact the fill in 4" lifts.

 

[crbr]

Out...

 

[treman]

Either way you should take them out. You decide weather its with a grinder or a backhoe.

 

[Stimw]

They will rot! The ground will sink!
They will cause more problems than you want to deal with. Taking them out will save you a lot of grief later.