Hello. I want to continue this line. Underneath the toilet there is a 1/2" pipe from the wall. There is an angle stop which line goes to the toilet.
On the 1/2" pipe I want to put a 1/2" T. One line goes to the toilet and the other line continues to the wash-basin. My question is if I should worry that the water from the toilet tank back-flows to the new line and to the wash-basin. Can I install a back-flow preventer ?Thanks.