Pressure for two shower heads

Hi. Im replacing the grunge filled steel supply to my bathroom. Im new to plumbing so my plan was just to replace what is there with the same size pipe. However, Im thinkig of adding a second shower head and im worried about the pressure if both heads are used at once. Curently, there is run of approx 20feet of 1/2inch to the shower(no bath). Im wondering if it would be adviseable to run 3/4inch up to the stall then split it to two 1/2 inch lines. Would that help or make a difference? Or should the 1/2 inch be fine?
Thanks
JJ

As long as the heads meet the current codes, they can't deliver more than 2.5gpm each. A 1/2" supply can handle that. Some valves can't ( although most do), so you need to watch that. If you remove the restrictor, then yes, bigger supply is good. Keep in mind that you'll need a significant WH to keep up if the shower is more than short. You can only get maybe 2/3-3/4 of the hot water out of a tank before it is diluted enough by the cold incoming before it gets unpleasant. It depends on the temp you set the thing to and the incoming (colder in the winter!) water. If the supply line from the street is restricted, it won't matter much until you replace it.

James,

Are you aware that there are valves that will regulate two heads in a shower?

I recently installed one of these. I used a 1/2" feed and the valve handled the rest.

Tom

Thanks for the quick reply. I appreciate the info. Its the second bathroom so i guess ill go with what ive got. I had already installed the 1/2 inch pipe. I used PEX and the walls are still open so change wouldnt be a BIG deal but its not alot of fun doing things twice!The second shower head is just a thought.
JJ

No, I was not aware of that. Do these valves balance the pressure betwee the fixtures or just switch back and forth between the two?

I don't know the answer to that one yet because I'm still in the tiling phase. I would imagine that they do regulate the pressure but I don't know.

If you willing to order online check out plumbers surplus. Do an internet search.

Tom