Purchased a home on a well (well pressure is good) and owner prior to the last changed plumbing to PEX. Problem is they ran 1/2" from supply to everything so water pressure is non-existent. Upgrading the supply lines to 3/4" and have several questions. Can the 1/2" to the water heater remain? Is there a product that meets code to insulate PEX as it is connected directly to the gas water heater or do they need to be changed out to copper 18" above connection? Right now they are wrapped in some form of insulated covering. Almost all the corners are 90 degree sharkbite connectors, do those decrease pressure enough to be concerned or should they be replaced with longer runs of 1/2" and sweeping bends? The PEX is run above the drop ceiling in basement so it connects directly back to the copper pipe leading to the bathroom and kitchen right at the floor line, thinking to leave those connections as is since only running new 3/4" supply. The way all the existing is run it goes from the water softener, runs up the wall and branches off in several directions towards the laundry room, bathroom and kitchen. To reroute everything would mean redoing the whole system and start from scratch. Any thought? Had a plumber come by and the way I am doing is what they had planned. Thanks, Any insight would be appreciated.

I want to replace my old top-mount sink with an undermount sink, which would result in the outflow pipe from the garbage disposal being only 1.25 inches above the outflow of the P-trap. I've read that the p-trap should be no more than 24" below the outflow from the garbage disposal, but there is no minimum distance. Will water have trouble flowing out of the garbage disposal if the p-trap outflow is only 1.25" below the garbage disposal outflow? Thank you. [img]https://cimg4.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1294x417/old_and_new_sink_ec886833e23df01c0be1014a7117b280a5812d1b.png[/img]