How far apart do 1/2 copper pipes need to be supported on straight runs?

No more than 10' and there is not penalty if you go shorter. Do not just use pipe wire hangers especially with hot runs. You need a plastic hanger than holds the pipe firmly but will allow for heat expansion.

I am replacing cast iron that runs behind a bathtub, if I support on both side of the tub should I be all right? I was considering using suspensulators on one side and copper strap hangers on the other as this seemed easiest for the retrofit. Is this all right?

In my code book... 1/2" copper pipe needs to be supported every 6 feet or less so a hanger on each side of the tub (tubs are 5 feet, typically) will be fine. Suspensulators and strap hangers will work well here.

Now, what's this about cast iron pipe? You aren't replacing cast iron pipe with 1/2" copper...right? It may be galvanized piping or even brass piping, but never cast iron pipes for water???

Or are you also replacing 2, 3 or 4" cast iron waste pipe? If so, you will need beefier hangers (such as A-BAND hangers) to hang these pipes. Let us know more so we can be sure you are using the right hangers for the job!

MARK

In my code book...1/2" copper pipe needs to be supported every 6 feet or less so a hanger on each side of the tub (tubs are 5 feet, typically) will be fine. Suspensulators and strap hangers will work well here.

Now, what's this about cast iron pipe? You aren't replacing cast iron pipe with 1/2" copper...right? It may be galvanized piping or even brass piping, but never cast iron pipes for water???

Or are you also replacing 2, 3 or 4" cast iron waste pipe? If so, you will need beefier hangers (such as A-BAND hangers) to hang these pipes. Let us know more so we can be sure you are using the right hangers for the job!

MARK

Sorry Mark, galvanized water supply it is. I'll start drinking AFTER I post next time. Thanks!

Good news... just didn't want you hanging any 2" cast iron pipe with copper strap hangers... ;)

Thanks...

MARK