If I get up tomorrow at a reasonable time I will do a thread on plumbing, in Thailand there is plumbing and there is plumbing, a Thai plumber will be doing plumbing on nice big multi story buildings using lead pipe(ok maybe galvanised), a plumber will be doing crap jobs on houses running crappy old blue pipes, my bet is your doing a house but want a plumber that does multi story buildings, there is a big price difference.