What is the recommended potable water pressure in a house?

Potable water pressure in a Quebec residence must comply with Plumbing Code standards for comfort and safety:

• Optimal pressure: 40 to 60 PSI
• Minimum pressure: 20 PSI at the highest point of use (2nd floor shower)
• Maximum pressure: 80 PSI at the meter (above this, a pressure regulator is mandatory)

Pressure-related problems:

• Too low (< 30 PSI): Insufficient flow, weak shower, slow tank filling. Solution: booster pump ($300 to $800)
• Too high (> 80 PSI): Risk of leaks, pipe noise (water hammer), premature wear of washer/dishwasher solenoid valves. Solution: pressure regulator ($150 to $300 installed)

How to measure: Use a pressure gauge that screws onto an outdoor or laundry faucet. Available at any hardware store for about $15. Measure in the morning (static pressure) and with a faucet open (dynamic pressure).