Where to start replacing galvanized pipe?
Our house is about 100 years old, with galvanized internal pipes. At some point, copper was run from the street, through the meter, to the HW tank. Copper coming out of the tank is tied into the old galvanized pipes. Same for the cold water lines. Water barely flows in 2nd floor bathroom, which has the only tub/shower. I know the pipes need to be replaced. The question is where to start? At the bathroom or in the basement? Hot or cold first?
I should add that the pipes goingto the bathroom have a vertical run from the basement, then horizontal for about 12 - 13 feet to the tub. The horizontal run is accessible through the ceiling of the first floor room (kitchen) they traverse. (Kitchen ceiling is done with close-drop 2x2 tiles to hide leak damage over the year to the old style plaster board.)
Also, there are frequent blockages in the drains from vanity and tub. Those are also galvanized.