What water pressure is adequate, and how high is too high?
This depends on the needs of the family moving into the home and the number of fixtures in the home. If there is a single guy moving into a 2700 square foot home, the chances he is going to feel like there is not enough water pressure is pretty low. A family of 6 moving into the same home may have quite a different experience with multiple shower heads, laundry, dishwasher and faucets running at all times of the day and night.
Ideal water pressure for most residential homes is around 60 PSI. Water pressures below 40 PSI are too low for most families while pressures above 80 PSI can and will damage plastic Pex or Poly-B waterlines in a home. High water pressure and water pressure surges are the cause of many leaks and million of dollars in damage in Calgary every year.
A pressure reducing valve (PRV) can be installed just above the main shut off valve in the basement. A PVR is adjusted to allow only a certain amount of water pressure. Some areas have excess water pressure coming from the city and a PVR is required. Often home owner try to tamper with these units to get more water pressure. This puts the home at a high risk of water damage from a ruptured waterline.
PVR's should only be adjusted by a licensed plumber.
During an inspection I like to run the laundry and dishwasher at the same time. Then I go to the hallway bathroom upstairs and run the faucet on full, the shower head on full, and flush the toilet a few times. The clients see this and they can judge for themselves if the water pressure is adequate.
Water pressures above 80 PSI can be recognized at fixtures that seem to explode with water when turned on and it also causes a high pitched noise at shower heads a lot of the time. I use a water pressure gauge in situations where I suspect too much water pressure for a more accurate measurement.
We are very lucky to live in Calgary, Airdrie, Okotoks, Cochrane, and other local areas where water pressure and cleanliness is very reliable.