Pipes and Repiping

Homeowner Summary

Your home's plumbing pipes are its hidden circulatory system — miles of piping running through walls, floors, and ceilings, delivering clean water to every fixture and carrying waste away. Because pipes are mostly invisible, problems often develop silently for years before they surface as discolored water, low pressure, or a catastrophic leak.

The material your pipes are made of determines their lifespan, vulnerability, and whether you should be planning a repipe. Copper pipes can last 50-70 years. PEX tubing (the modern standard) lasts 40-50+ years. But if your home has galvanized steel or polybutylene pipes, you may be on borrowed time — these materials are known to fail and can be difficult or impossible to insure.

A whole-house repipe is a significant investment ($4,000-$15,000), but it eliminates the risk of hidden leaks, improves water quality and pressure, and adds real value to your home. Knowing your pipe material, its condition, and the warning signs of failure helps you make an informed decision about when — not if — to repipe.

How It Works

Your plumbing system has two distinct pipe networks:

Supply pipes carry pressurized clean water from the municipal main or well into your home and distribute it to every fixture. These operate at 40-80 PSI and branch into hot and cold lines. Supply pipe failures cause the most damage because the water is under constant pressure.

Drain-waste-vent (DWV) pipes carry wastewater away from fixtures by gravity. They connect to the main sewer line or septic system. Vent pipes extend to the roof to allow air in, preventing vacuum locks that would stop drainage.

Pipe Materials

Copper (1950s-present): The gold standard for supply lines. Type M (thinnest wall) for residential supply; Type L for underground or higher-pressure applications. Joined with solder or press fittings. Lifespan: 50-70 years. Vulnerable to pinhole leaks from acidic water (low pH) or aggressive water chemistry.

PEX (Cross-Linked Polyethylene) (1990s-present): Flexible plastic tubing that has largely replaced copper in new construction. Color-coded (red = hot, blue = cold, white = either). Connected with crimp rings, clamp rings, or expansion fittings. Lifespan: 40-50+ years. Cannot be exposed to UV light. Freeze-resistant (can expand without bursting).

CPVC (Chlorinated Polyvinyl Chloride) (1960s-present): Rigid plastic pipe rated for hot water. Joined with solvent cement. Lifespan: 25-40 years. Becomes brittle with age, especially in hot environments (attics, near water heaters). Vulnerable to cracking from certain chemicals (some insecticides, adhesives).

Galvanized Steel (pre-1960s): Steel pipes coated with zinc to prevent rust. The zinc layer corrodes over time, then the steel corrodes from the inside out, restricting flow and contaminating water with rust. Lifespan: 40-60 years, but most are well past their useful life. A strong candidate for repiping.

Polybutylene (PB) (1978-1995): Gray plastic pipe (marked "PB2110") that was widely used as a cheaper alternative to copper. Known to fail prematurely due to degradation from chlorine in municipal water, causing sudden, catastrophic leaks. Many insurers refuse to cover homes with polybutylene. If your home has it, plan to repipe.

Cast Iron (DWV, pre-1970s): Heavy, durable drain pipe. Lifespan: 50-100 years, but joints deteriorate and the pipe corrodes from the inside. Common failure: bellied sections and joint separation.

ABS/PVC (DWV, 1970s-present): Lightweight plastic drain pipe. ABS is black; PVC is white. Both are durable with lifespans of 50+ years. PVC is more common in modern construction.

Maintenance Guide

DIY (Homeowner)

• Know your pipe material: Check exposed pipes in the basement, crawl space, or utility room. Copper is copper-colored (or green with patina). PEX is flexible colored tubing. Galvanized is gray metallic with threaded fittings. CPVC is cream/off-white rigid plastic.
• Check water pressure annually: Use a pressure gauge ($10 at any hardware store) on a hose bib. Normal range is 40-60 PSI. Over 80 PSI stresses pipes and fittings.
• Inspect visible pipes for signs of corrosion, green staining (copper), mineral buildup, or moisture.
• Insulate exposed pipes in unheated areas (crawl spaces, attics, exterior walls) to prevent freezing. Use foam pipe insulation sleeves.
• Know your main shutoff location and test it annually — turn it off and on to ensure it operates. A stuck shutoff valve is useless in an emergency.
• During freezing weather: Open cabinet doors under sinks on exterior walls. Let faucets drip if temperatures drop below 20 degrees F (-7 degrees C).
• Never pour grease down drains — it solidifies and causes blockages in DWV pipes.

Professional

• Biennial inspection: Visual inspection of accessible piping, check for corrosion, leaks, and proper support/hanging. Test water pressure at multiple points.
• Water quality testing: Test pH, hardness, chlorine levels, and dissolved solids. Acidic water (pH below 6.5) accelerates copper corrosion. Hard water causes scale buildup.
• Camera inspection (if age or symptoms warrant): Run a sewer camera through drain lines to assess condition, check for root intrusion, bellying, or joint separation.
• Galvanized assessment: If home has galvanized supply lines, check interior condition with a flow test (measure GPM at the farthest fixture) and water discoloration test.
• Leak detection survey: Use acoustic or thermal detection to identify hidden leaks in walls or under slabs.

Warning Signs

• Low water pressure — especially if it has gradually worsened over months or years (galvanized pipe corrosion)
• Rusty, brown, or discolored water — internal pipe corrosion (galvanized or old copper)
• Discolored water after the system sits idle (morning or after vacation) — active corrosion
• Visible corrosion or green/blue staining on copper pipes or fittings
• Pinhole leaks — small leaks in copper pipes, often appearing as green-crusted spots
• Frequent leaks in different locations — systemic pipe deterioration, not isolated failures
• Water stains on ceilings or walls — hidden pipe leaks
• Unexplained increase in water bill — hidden leak in supply piping
• Musty smell in walls or under floors — ongoing moisture from hidden leak
• Dimpled or flaking pipe surfaces on galvanized pipes — advanced corrosion
• CPVC pipes cracking when bumped — brittleness from age and heat exposure
• Any polybutylene piping present — replacement should be planned regardless of current condition

When to Replace vs Repair

Replace (full repipe) when:

• Home has polybutylene piping — plan proactively, don't wait for failure.
• Galvanized pipes are showing reduced flow, rust, or multiple leak points.
• You're experiencing recurring leaks (3+ in different locations within 2 years).
• Water quality testing shows elevated lead or metal levels from pipe corrosion.
• CPVC has become brittle and is cracking during routine work.
• You're renovating and walls are already open — the ideal time to repipe.
• Insurance carrier requires it for continued coverage.

Repair when:

• A single isolated leak in otherwise sound piping.
• A damaged section is accessible and localized.
• Copper pipes have one or two pinhole leaks but are otherwise in good condition.
• A joint or fitting has failed, not the pipe material itself.

Partial repipe: Sometimes the best option — replace only the problematic sections (e.g., the galvanized supply lines) while leaving sound DWV piping in place.

Pro Detail

Specifications & Sizing

Residential supply pipe sizing (typical):

| Application | Pipe Size | |-------------|-----------| | Main supply (street to house) | 3/4 inch or 1 inch | | Branch lines (to fixtures) | 1/2 inch | | Trunk lines (main distribution) | 3/4 inch | | Water heater supply/outlet | 3/4 inch | | Outdoor hose bibs | 1/2 inch or 3/4 inch |

Flow rate requirements:

| Fixture | Minimum Flow (GPM) | |---------|-------------------| | Shower | 2.0 | | Kitchen faucet | 2.2 | | Bathroom faucet | 1.5 | | Dishwasher | 1.5 | | Clothes washer | 3.0 | | Toilet fill valve | 3.0 |

DWV pipe sizing:

| Fixture/Application | Pipe Size | |---------------------|-----------| | Lavatory sink | 1-1/4 inch or 1-1/2 inch | | Kitchen sink | 1-1/2 inch or 2 inch | | Toilet | 3 inch (4 inch for building drain) | | Shower/tub | 2 inch | | Main building drain | 4 inch | | Vent stack | 2 inch minimum through roof |

PEX specifications:

• PEX-A (Engel method): Most flexible, best freeze resistance, expansion fittings. Highest cost.
• PEX-B (Silane method): Slightly stiffer, crimp or clamp fittings. Most common. Good balance of cost and performance.
• PEX-C (Radiation method): Least flexible, most prone to kinking. Least expensive.
• All rated for 200 degrees F at 80 PSI (per ASTM F876).

Common Failure Modes

| Failure | Material | Cause | Timeline | |---------|----------|-------|----------| | Internal corrosion/rust buildup | Galvanized | Zinc coating depletes, steel corrodes | 40-60 years | | Pinhole leaks | Copper | Aggressive water chemistry, pitting corrosion | 15-40 years | | Chlorine degradation | Polybutylene | Chlorine in municipal water attacks plastic | 10-25 years | | Brittle cracking | CPVC | Heat exposure, age, chemical incompatibility | 20-35 years | | Joint failure (solder) | Copper | Flux corrosion, poor workmanship, thermal cycling | Variable | | Fitting failure (crimp/clamp) | PEX | Improper installation, dezincification of brass | 10-30 years | | Scale buildup | All metallic | Hard water (high calcium/magnesium) | Ongoing | | Freeze burst | Copper, CPVC | Water expansion in unprotected pipes | Seasonal | | Electrolysis/galvanic corrosion | Copper + galvanized | Dissimilar metals in contact without dielectric union | 5-15 years at junction |

Diagnostic Procedures

Flow rate test (checking for pipe restriction):

1. Close all fixtures in the home.
2. Attach a flow meter or use a 5-gallon bucket at the hose bib nearest the main.
3. Open fully and time how long to fill 5 gallons. Calculate GPM.
4. Repeat at the farthest fixture from the main.
5. Compare: significant drop-off (>30%) indicates restriction in the piping.
6. On galvanized systems, flow below 4 GPM at the main hose bib indicates severe internal corrosion.

Leak detection (hidden leaks):

1. Record the water meter reading. Ensure all fixtures and appliances are off.
2. Wait 2 hours without using any water. Re-read the meter.
3. Any movement indicates a leak in the supply system.
4. Use acoustic leak detection equipment to pinpoint location.
5. Thermal imaging can reveal moisture in walls from active leaks.

Pipe material identification:

1. Locate accessible piping (basement, crawl space, utility room, under sinks).
2. Copper: Reddish-brown metal, may have green patina. Soldered joints.
3. Galvanized: Gray metal with threaded fittings. Use a magnet — it will stick.
4. PEX: Flexible colored tubing (red, blue, white) with metal crimp rings.
5. CPVC: Rigid cream/yellow plastic with cemented fittings. Marked "CPVC."
6. Polybutylene: Gray or blue flexible plastic marked "PB2110." Check under sinks and at the main shutoff.

Galvanic corrosion assessment:

1. Look for dissimilar metal connections (copper to galvanized) without dielectric unions.
2. Check for white or green deposits at connection points.
3. These junctions corrode rapidly and are often the first point of failure.

Code & Compliance

• Approved materials: UPC and IPC specify approved pipe materials for supply and DWV applications. PEX, copper, and CPVC are universally accepted for supply. Some jurisdictions have restrictions (e.g., PEX was banned in some California municipalities until 2010).
• Dielectric unions: Required when connecting dissimilar metals (copper to galvanized or steel) to prevent galvanic corrosion.
• Support and hanging: Copper must be supported every 6 feet horizontally, 10 feet vertically. PEX every 32 inches horizontally. All piping must be properly supported to prevent sagging and stress on joints.
• Thermal expansion: PEX expands significantly with temperature changes. Installation must allow for expansion loops or offsets.
• Penetrations: Pipes through framing members must maintain structural integrity — notching and boring limits per code (typically no more than 40% of stud depth for notches, 60% for bored holes).
• Shutoff valves: Individual shutoff valves required at every fixture per modern code.
• Lead-free: All pipes and fittings for potable water must be lead-free per the Safe Drinking Water Act (weighted average of 0.25% lead maximum).
• Permits: Whole-house repipe requires a permit in virtually all jurisdictions. Inspections typically required at rough-in (before walls are closed) and final.

Cost Guide

| Service | Typical Cost | Factors Affecting Price | |---------|-------------|------------------------| | Whole-house repipe (PEX) | $4,000-$10,000 | Home size, number of fixtures, accessibility, stories | | Whole-house repipe (copper) | $8,000-$15,000 | Copper material cost, labor intensity | | Partial repipe (one section) | $1,500-$4,000 | Length of run, accessibility, wall/ceiling repair | | Single pipe repair (accessible) | $200-$500 | Location, pipe material | | Single pipe repair (in-wall) | $500-$1,500 | Drywall cutting and repair, access | | Slab leak repair | $1,500-$4,000 | Detection, reroute vs direct repair | | Pipe insulation (whole house) | $300-$600 | Linear footage, access | | Water pressure regulator install | $250-$500 | Valve cost, location | | Leak detection service | $200-$500 | Equipment used, property size | | Emergency pipe repair (after-hours) | $300-$800+ | Time premium, severity |

Costs reflect national averages. Two-story homes and slab construction increase repipe costs by 20-40%. Drywall repair may be additional.

Energy Impact

Piping doesn't consume energy directly, but it significantly affects energy efficiency:

• Uninsulated hot water pipes lose 2-4 degrees F per foot traveled in unconditioned spaces. Insulating hot water pipes saves 3-5% on water heating costs and delivers hot water faster (reducing water waste).
• Pipe runs and layout matter: homes with centrally located water heaters and shorter pipe runs waste less energy and water waiting for hot water to arrive at distant fixtures.
• Recirculation systems eliminate the wait for hot water but add energy cost unless they use a demand-activated pump (on-demand systems use 80-90% less energy than continuous recirculation).
• Leaks waste both water and energy: A hot water pipe leak wastes heated water — even a small drip at 1 drop per second wastes 3,000+ gallons per year.
• Water pressure: Excessive pressure (over 80 PSI) increases water usage at every fixture, increasing both water and water-heating costs.

Shipshape Integration

Shipshape's SAM platform provides critical monitoring and management for home plumbing systems:

• Pipe material and age tracking: SAM records the pipe material, estimated age, and condition for each home, enabling proactive repipe recommendations before failure occurs. Homes with polybutylene or aged galvanized pipes are automatically flagged for dealer follow-up.
• Leak sensor monitoring: Smart leak sensors placed at key locations (water heater, under sinks, near washing machine, by main shutoff) provide real-time leak detection alerts. Early detection prevents the average water damage claim ($11,000+).
• Water flow monitoring: Integration with whole-home water flow sensors tracks usage patterns and detects anomalies — a toilet running continuously, a slow slab leak, or a supply line micro-leak that hasn't yet surfaced.
• Freeze risk alerts: SAM correlates local weather data with the home's pipe insulation status to generate freeze warnings. Homeowners receive proactive alerts before temperatures drop below critical thresholds.
• Water pressure monitoring: Connected pressure sensors track system pressure over time, identifying gradual pressure loss (hidden leak) or excessive pressure (PRV failure).
• Home Health Score impact: Pipe material, age, and condition are significant factors in the overall Home Health Score. Homes with polybutylene pipes or aging galvanized lines receive lower scores with clear recommendations for improvement.
• Dealer opportunities: SAM generates repipe leads for dealers when homes cross age thresholds, experience multiple leak events, or when insurance requirements drive replacement. The dealer dashboard shows estimated job scope and recommended materials.