Uhhh, why not just lay the 2x6 on the floor next to the pipes and use a speed square to mark the locations of the pipe penetrations? From there it's a simple matter to just core drill the plate and set it down on top of the foam strip...
I saw you put some plastic? between the bottom plate and the concrete, does that allow you to not use treated on the bottom? Is that plastic something available in home depot? PS...Your daughter is a great helper!
That was a foam insulation product called Sill Seal. It is readily available at any big box home improvement store and can be found in the insulation aisle. I still used treated lumber for my bottom plated, but the sill seal does help prevent moisture from the concrete from wicking up into the wood. It primarily helps with draft and keeping critters out though. Thanks for watching.
It's a moisture barrier. It keeps the cement which can be caustic and can sometimes react with the chemicals in the pressure treatment. It also serves as an air sealant as well as preventing the transfer of temperature from the concrete to the walls.
