What size pipe should you use to attack the toilet plumbing to the main line?

1/2" tubing. Not pipe. If we are talking about copper.

The toilet is attached via a 3/8 compression line from the toilet supply valve.

Depending on how your plumbing your toilet you can use a chrome plated pipe nipple.

The accepted quick way is a 1/2 (5/8) to 3/8 compression angle stop if you don't care how it looks.

Hi all:

If water piping then you would run 1/2" copper tubing (TYPE L tubing) to the toilet and then install a shutoff that reduces to a 3/8" compression fit so you attach a 3/8" compression x 7/8" toilet nut x12" long flexible toilet supply tube.

If waste piping then a toilet requires a 3" pipe at a minimum!

Let us know if need more here...

MARK

Can you clarify as to whether you are asking about water supply or drain/waste. I guess either way your guestion has been aswered. But I'm just curious, please let me know.

Very vague description of the problem. Please, be more specific. Repost details. Thanks

what size pipe should you use to attack the toilet plumbing to the main line?

I'm assuming that you're referring to drainage. In my area the code calls for 4" under the slab and 3" if on a second story bathroom. Good luck and thank you for rating my reply. Tom

My code allows three inch under slab or anywhere for up to two toilets. If you have more than two toilets on the same main line, then you must increase to four inch. I think you would be fine with 3 ", but you would need to check your local codes. The codes vary(way more than they should).