Installing Pex Questions

Good morning. I am redoing all of my water supply with pex. I have an upstairs area that I am going to turn into an apartment for my mother. I was planning on running 3/4 pex up there, and cap it untill I am ready to redo that area. My water pressure is close to 70lbs. I was going to run a separate hot water tank, and all of the water supply for that area off of that 3/4 line, will that work? I was going to run that 3/4 pex line to this area off of the main 3/4 service before I tie in my pex 1/2 manifolds to the rest of the house. Is that right? I am also planning on running a 3/4 line off of the main 3/4 service to the main house hot water tank, and then pex off of a 1/2 manifold. Is that right?...thanks

Without knowing distances and length of runs we couldn't tell you. Your plumbing code book has an entire section on properly sizing water supply and distribution piping and should be used.

piping

Your building department will TELL you what size lines to install when you submit your plans and specifications to them for the permit and inspections.