craigjl

I'm not sure what the compaction standards are for 2B but 4" of 411 compacted at two inch rises with a vibratory plate compactor makes a pretty sturdy base. In our area we would typically set something like a paver patio on four inches with pretty good success. So, going with a couple more inches likely will not hurt. If you go that route I doubt that you would need any type of tub pad system. It is important to make sure that you compact evenly and don't try to compact the entire six inches at once.