Raised Slab on Stem Wall

[HowardStronglast]

I'm trying to create a raised slab foundation with a stem wall that is 30" above grade.  So the top of the slap is 30" above grade.  The garage should be at grade obviously.  This should be easy, but I'm struggling.

 

Thanks.

[joey_martin]

Open the floor dialog box and delete the sub-floor layer, then change the framing layer to 4" and concrete, uncheck the framing box. That's it, don't overthink it.

[Doug_N]

 

10 hours ago, joey_martin said:

Open the floor dialog box and delete the sub-floor layer, then change the framing layer to 4" and concrete, uncheck the framing box. That's it, don't overthink it.

 

I am sure that Joey was using 4" as an example only.  You set that dimension to whatever the slab thickness is.  4" might be a bit thin for a suspended slab with significant spans.

[mtldesigns]

On 7/25/2025 at 9:43 PM, HowardStronglast said:

This should be easy, but I'm struggling

What part are you struggling with Howard?  The floor of the garage at grade?

Remember, your main floor is always (well most of the time) at zero inches.  Set your terrain at -30".  Set the floor elevation of the garage at -30" as well.  (that would be in the room dbx, under structure at the FLOOR input.