frozen shower arm

I'm installing a new trim kit in my master bath. I just remodeled the bath with full tile walls. To be on the safe side I was going to break the shower arm loose before the tiles went up but with all the craziness of getting everything done quickly I forgot. I had a pipe wrench on it this morning with quite a bit of pressure to no avail. I'm deathly afraid of breaking the pipe. Any tips or tricks to get this thing off without damaging supply lines?? thanks

Squirt some vinegar or penetrating oil in there. Repeat every hour all day. Then give it a try. Shower arms are thin, so no matter what you do, there is the possibility it will break. That too can be fixed. Post back here for some tips .

Sometimes a pipe wrench tends to squeeze the pipe therefore making it harder to turn. I like to use the Channel Lock that has curved jaws and they have a lot less chance of egg shaping the pipe.

You might try to tightening it just to make it move.

Start by grabbing the shower arm away from the wall.