With the removal of the cast iron piping yesterday, we were quickly and easily able to rough out the PVC to the right areas. The 3″ PVC helped to get the toilet flange into the right area plus we were able to get the sink and tub drain tied in with the proper pitch to drain correctly. The way we tied into the existing 4″ PVC was to simply add a 4″ x 3″ reducer int he wall of the laundry room. We did that by cutting a hole in the wall behind the vanity mirror and add a 6×9″ access panel.
Here is the rough test fit before we started gluing for final assembly.
After the test fit, it was right to gluing. Regular PVC primer and cement were used but before I did that, I used a sharpie to make guides on the PVC so I know how to assemble the entire piece in one shot. You will see in the image below how I used simple lines and numbers to coordinate it all together.
After the drains were glued I cut the PEX plumbing and crimped all the pieces together.