leaky pipes---there could be 100's of reasons but some you might not think of include that those leaks are there on purpose!
remember that plumber you insulted, did'nt pay fully, the one you thumbed your nose up at--well he could have revenge after all.
that pipe he replaced---it looks fine and works fine when you tried it but he intentionally left off the glue that would hold that new pipe together with the old pipe. It didn't fail for 2 months but when it did the damage was enormus.
new pipes needed, new drywall,new carpets,new paint etc.
you must know who you hire and treat them with respect if not you could havethose leaky pipes!
www.remodelinghellthebook.com will save you $1,000's potentially!