Inspected a 2 story Colonial last week. During the Master Bath inspection (2nd floor), I opened the faucets on the tub and sink simultaneously and opened the shower faucet at the same time. The water barely dripped from the shower, indicating a pressure issue. I placed my water pressure guage on an outside hose bib and recorded a pressure reading of 37psi. This home is served by a private community water system. I noted in my report that the pressure is below normal, and recommended for the realtors to contact the water company. Their response was 35 psi is their normal presure setting for the entire system.
The copper supply lines to the second floor are 3/4", so there should not be much of a pressure drop to the second floor bathrooms. The 2006 IRC calls for a minimum pressure of 40 psi. I have never had an issue with low pressure on a relatively new home (10 yrs.) serviced by a public system. Any thoughts??