The pipe was installed over 8 years ago when we did the upstairs and added a full bathroom. All work done was inspected by the city and passed. Never had a problem so we are sure it was from freezing. DH and plumber friend did not mention any corrosion and that is a word I would have picked up on. We had an industrial big fan blowing across that area and a regular people type fan blowing in another area for 3 days straight so I think we got it dried out. The hardwood was dry. It is buckling now. Looks like that is happening everywhere there was water. We mopped up pretty quick so the water was not there for many hours.
Shari,
Put a fan (or fans) blowing across the floor to dry them out. That should stop the floor from warping any further.
One piece vs. 2 pieces shouldn't really make a difference as long as the job is done correctly. Did the pipe burst from freezing, or corrosion? (If the flux isn't cleaned off after soldering, or too much was used inside that will cause the joints to corrode).
That's one of the reasons (besides cost) they're starting to use plastic pipes a lot more nowadays.....