Whole-Home Repipe in San Mateo, California

The highest-risk pipe materials: galvanized steel (orange/brown discolored water, reduced pressure throughout the house, corrosion visible on exposed sections), polybutylene (grey flexible plastic, installed 1978–1995, known to crack from chloramine exposure in treated municipal water), and lead pipe (homes built before 1930 with grey or dull silver pipes). Additional indicators for any material: recurring pinhole leaks at multiple locations within 12–18 months, persistent low pressure that doesn't improve with fixture cleaning, and brown staining that returns at fixtures after cleaning.

PEX-A (cross-linked polyethylene, Uponor type) is the dominant choice for residential repiping today: flexible (reduces the number of fittings needed), freeze-resistant (expands rather than splitting at 32°F), compatible with push-fit and expansion fittings, and CPVC-compatible. Copper remains the premium choice in very soft or aggressive-water markets where long-term PEX chemical compatibility is a concern, and in high-temperature applications. Both carry 25-year manufacturer warranties when properly installed. PEX-A is typically 20–30% less expensive in total installation cost due to fewer fittings and faster installation.

A single-story 3-bedroom home with accessible walls takes 2–3 days for PEX installation. A two-story home or a home with difficult access (slab-on-grade, finished basement, tile over all plumbing walls) takes 3–5 days. The timeline includes: opening access at each rough-in point, running new distribution lines, reconnecting all fixtures, pressure testing, and patchwork inspection. Drywall patching and painting is a separate scope, typically done by a different contractor after the plumber closes out the permit.

Almost always, yes — significantly. Galvanized pipe corrodes from the inside, and the corrosion layer narrows the pipe bore progressively over 30–50 years. A ¾-inch galvanized supply line can effectively narrow to ¼-inch bore after decades of scaling, cutting pressure and flow dramatically. New PEX-A or copper maintains full interior bore indefinitely. Most homeowners report noticeably improved pressure and faster hot-water delivery within the first week after repipe. It also frequently resolves "low cold pressure when someone showers" problems caused by restricted cross-section in undersized corroded lines.

A plumbing permit is required in all jurisdictions for a whole-home repipe. The city inspector visits for a rough-in inspection (before walls are closed to view pipe routing and connection methods) and a final pressure test. Maintaining the permit documentation is important: it's required for resale disclosure, and some homeowners insurers offer premium reductions after a documented galvanized-to-PEX or lead-to-copper repipe. The plumber schedules all inspections and provides the closed permit record when the job is complete.

San Mateo water hardness of 10 gpg is in the hard range, where scale builds up quickly inside water heaters, tankless units, and pipes. A whole-home water softener pays for itself through extended appliance life in this hardness range. Tankless water heaters in this market need descaling every 18–24 months to maintain warranty compliance and efficiency.

With a median home age of 60 years, a significant share of San Mateo's housing stock was built before modern plumbing codes and materials standards were established. Homes from the 1960s–1970s frequently contain Orangeburg sewer laterals (bituminized fiber that softens with age), galvanized supply lines, and copper pipe that has been in service for 50+ years. This vintage of housing generates disproportionate sewer-line, repipe, and slab-leak call volume relative to newer stock. The plumber's assessment should include a pipe material evaluation as part of any diagnostic call.

San Mateo has a documented lead service line inventory (Unknown). A full repipe of the interior supply lines eliminates lead exposure risk inside the home, but the lead service lateral from the main to the house meter is a separate replacement — typically handled by the city's LSL replacement program. Ask the plumber to distinguish between the interior supply repipe scope and the lateral, and check with San Mateo's utility department about the public-side replacement status for your address.

Whole-Home Repipe in San Mateo typically runs $4,500–$18,000. Total linear footage, material choice (PEX vs. copper vs. CPVC), number of fixture connections, and permit inspection hold points drive cost at the high end. Foundation slab penetrations, finished-ceiling access, and drywall restoration are typically scoped separately. Footage and material are confirmed from a full-property walkthrough before quotes are issued.

Yes. Every plumber matched through AlertPlumber holds an active California state contractor license. The California licensing database is checked at each routing — not just at initial signup — so the status reflects current standing, including any recent disciplinary actions, renewals, or insurance lapses. Active California licensure requires documented proof of bonding, liability coverage, and continuing education current as of the routing date.

AlertPlumber is free to homeowners. The referral fee is paid by the plumber when they accept a qualified call — it is their customer-acquisition cost, not an added charge to you. The plumber provides a written price assessment before any work begins; if the quote doesn't fit your situation, there is no cost and no commitment.