Final Floor specs

[mshedb]

Too much fill in my backyard has required me to bite the bullet and excavate and remove 3' of the backyard. Into this large, 26x32' hole will go:

28" of crushed gravel, mechanically compacted in 6-8" lifts
6mil vapor barrier
2" foam insulation (Dow scoreboard 25psi R-value of 10)
6" 4000psi concrete slab, reinforced with #4 rebar, 2' centers, on chairs

will cost a bunch, but seems like the right way to do it.

comments before the architect commits this to paper?

 

[TonyMazz]

Why do you need a floor the depth of a freeway ? What are you going to do in there ? Lift semi tractor's ?

28" of crushed gravel will handle 15KPSI.....tell us what your plans are...

Certainly everything you have mentioned is high end, so it will be probably the best you could do...but wondering if you need to go quite that far...just dont know what you are planning....tell us more

 

[rodnok1]

I don't know if it's pertinate, but couldn't you have it excavated then re-use most of the material again, just being compacted properly? After 28" of properly compacted subbase, I couldn't see you needing 6" of concrete either.

 

[mshedb]

Why do you need a floor the depth of a freeway ? What are you going to do in there ? Lift semi tractor's ?

28" of crushed gravel will handle 15KPSI.....tell us what your plans are...

Certainly everything you have mentioned is high end, so it will be probably the best you could do...but wondering if you need to go quite that far...just dont know what you are planning....tell us more

My engineer tested the soil and found that it was fill (3' thick) and unsuitable for use under the slab. It will settle over time. so, we excavate and replace with rock. 5" slab is enough (the lifts I am looking at call for 4 or 4.5" concrete and I want a little cushion).