Tughillrzr
In the Trades
I’m going to use all 4” under slab and reduce down to 2” at fixtures except toilets. All under slab plumbing. Upper bath group will drop down in 3” and tie into 4” main where noted. Only fittings under slab will be 4” wyes , 2” trap shower , 2” floor drain, 45’s and a few long sweep 90’s.