Being in the middle of replacing a galvanised iron water main to the house (the inground pipe has been replaced), we find it almost impossible to get under the house to complete the job. The questions are how long will a galvanised iron pipe last in free air under the house? Any answers to tight situations?
It will last a lot longer than a buried pipe. There is little external deterioration when it is above ground. The interior deterioration will occur regardless of where it is located.