I am remodeling my kitchen, and I need to modify the roof above. Currently it is flat (no slope) and water puddles on top (there are no leaks yet). It has some sort of continuous zinc-like covering - could this be what is called hot-mopped? I need to install an external range hood blower on the roof, but a friend told me that it would be extremely difficult to do that without introducing leaks, and that building a new sloped roof over the original would eliminate possible leaks and allow an easy installation of the ducting/fan on the roof. I have 2 questions: 1) Anybody got any suggestions about how to deal with the roof in general and 2) How can I go about finding all the building codes that would be related. I know there is the IRC, but how do find out about State, City codes - is there a perticular name for these organizations? I am in Washington state, near Tacoma; if anybody is familiar with the 'local' authorities, please let me know who I need to talk to about building codes, permits etc

TIA