Repiping & Water Pressure in St. George, UT

When repiping makes sense

• Repeat leaks. One slab leak can be bad luck. A second or third usually means the pipe itself is failing.
• Polybutylene. Gray plastic supply pipe, often stamped PB2110, was used in many homes built from the late 1970s to the mid-1990s, which covers a large share of St. George's growth years. Its fittings and the pipe itself are known to fail with age.
• Corroded copper. Pinhole leaks, green stains on pipe and repeated repairs are signs copper is thinning from the inside.
• Galvanized steel in older homes near downtown, which rusts and narrows over time.
• Remodels and additions where opening walls makes it the right time.

Materials

• PEX is the most common choice for repipes today. It is flexible, so it can be fished through walls and attics with fewer openings, and it handles freezing better than rigid pipe. It should be kept out of direct sunlight and protected in hot attics according to the manufacturer's instructions.
• Copper is durable and familiar, but it costs more in materials and labor, and its longevity depends on water chemistry and pressure.
• CPVC appears in some local homes and becomes brittle with age and heat.

Overhead instead of under the slab

Most St. George homes are on slabs, and many original supply lines run under the concrete. A repipe usually reroutes water lines through the attic and walls instead, which keeps them out of the shifting soils the Utah Geological Survey flags in this area (Utah Geological Survey, Geologic-Hazard Maps for the St. George-Hurricane Area) and makes future repairs far easier. Lines in the attic need insulation, both for summer heat and for the occasional freeze.

Water pressure

St. George is built on hills and benches, and water systems are divided into pressure zones. Homes at the low end of a zone can see high static pressure. The plumbing code calls for a pressure-reducing valve (PRV) when pressure exceeds 80 psi, and many homes have one near the main shut-off or in the meter area.

• Signs of high pressure: banging pipes, running toilets, dripping relief valves, leaking supply lines and short appliance life.
• Signs of a failing PRV: pressure that creeps up overnight, sudden low pressure, or a buzzing sound.
• Test it. A pressure gauge on a hose bib takes a minute. Something around 50 to 70 psi is typical for a home.
• Expansion tanks. A PRV creates a closed system, so a thermal expansion tank on the water heater is part of the same picture.

Hard-water scale can make PRVs stick, which is one more reason homes here benefit from a softener.

Lead

Lead pipe is uncommon in St. George's mostly newer housing, but the city's water quality report notes that homes built before the early 1900s commonly used lead pipes, lead service lines were used until the 1940s, and copper pipe was joined with lead-containing solder until the mid-1980s (City of St. George, 2024 Drinking Water Quality Report). The EPA has more on reducing exposure (EPA, Basic Information about Lead in Drinking Water).

What a repipe involves

1. Plan the routes from the main and the water heater to each fixture.
2. Open small access holes in walls and ceilings where needed.
3. Run new lines, connect fixtures and add shut-off valves.
4. Pressure test, inspect if a permit is required, and patch.

Ask who handles drywall repair and painting, how long the water will be off each day, and whether the permit and inspection are included.

Related guides

• How to Find Your Water Shut-Off and Check for Leaks in a St. George Home

Sources: City of St. George, 2024 Drinking Water Quality Report; EPA, Basic Information about Lead in Drinking Water; Utah Geological Survey, Geologic-Hazard Maps for the St. George-Hurricane Area.