Parallel or trunk and branch?

[Ledgewood]

Hey I have a 1950's home with a 3/4 copper main line entering the house which sizes down to 1/2 copper after the water heater for both hot and cold line trunks. I feel this main trunk is a bit undersized for a house with 4 cold water spigots, 2 full baths(one on the second level), kitchen/dishwasher, and washing machine. The farthest run from where the main line enters the house is 80 feet to the washing machine in the basement. And the upstairs bath is approx 50' from the water heater.

Now for my question- I have the upstairs bath gutted and have the opportunity to switch over to pex with a manifold home run system. My main concern is to have adequate water pressure throughout the house when running the upstairs shower and a lavatory at the same time. It would be easier and cheaper to keep with the existing trunk and branch set up, but this is my forever home and this new upstairs bath is our master and can foresee the routine every night of my wife in the shower while I'm brushing my teeth and don't want a lifetime of arguments because of water pressure.

I read the entire Pex Design Guide second edition that was linked in another post. From what I understand it seems like the parallel home run system can provide a more even distribution of the water/pressure. Is it enough to warrant a switch over, especially with the existing small 1/2 copper main Trunk?

Thanks for any advice.

 

[Terry]

3/4" in and then 1/2"?
I would go with a manifold off of the 3/4" and an expansion tank to buffer a bit.
No more than two fixtures on 1/2" is my rule.

 

[Sponsor]

 

[Ledgewood]

3/4" in and then 1/2"?
I would go with a manifold off of the 3/4" and an expansion tank to buffer a bit.
No more than two fixtures on 1/2" is my rule.

Thanks for the advise, I followed it. I attached a pic of the finished product.

 

[Jadnashua]

And now, how is it all working out for you?