I recently had a friend ask me if I could do an air test on the water pipes of a bank-owned home he's buying. Traditionally, these types of requests have been few and far between, but I've been getting more and more people asking about this with the high number of winterized bank owned properties for sale. I've always told my customers that we don't do this, but I've decided that it's time to start offering this service.
A pressure test is a way of checking for leaks in the water piping without actually having any water in the pipes. This consists of connecting an air compressor to the water piping, typically at the laundry faucet or exterior sillcock, and pressurizing the pipes to about 60 psi with air. This is similar to the water pressure that most homes will have from the street.
I use the device pictured at the right to connect an air compressor to the water piping. I make sure all of the faucets are turned off, then I pressurize the pipes. If they hold pressure, that's good. I then disconnect the air hose and leave the pressure gauge in place for the rest of the inspection. I come back at the end of my inspection and check the gauge to make sure the pressure hasn't dropped. If it has, there's a leak.
The limitations of this test are that I cannot check the drains, vents, traps, or plumbing fixtures for leaks, but it's better than nothing. I'll be charging a small fee to do this test with an inspection.
Reuben Saltzman, Structure Tech Home Inspections