PVC & CPVC Piping
Updated February 20, 2026
PVC for drain-waste-vent (DWV) and cold water; CPVC rated for hot water up to 200°F. Lightweight, affordable, and chemical resistant.
Overview
PVC (polyvinyl chloride) is the standard for residential drain, waste, and vent (DWV) lines. White PVC handles cold water and drainage. CPVC (chlorinated PVC) is a different formulation rated for hot water supply -- cream or tan colored. Both are lightweight, corrosion-proof, and joined with solvent cement (glue). PVC is not rated for hot water supply. CPVC is rated up to 200 degrees F. Do not mix them up -- using PVC on hot water supply lines is a code violation and a failure waiting to happen.
Pros & Cons
- Affordable
- Chemical resistant
- Lightweight
- Easy to cut
- Rigid (no flexibility)
- Cement joints are permanent
- PVC not for hot water
Key Features
- PVC: standard for drain, waste, and vent lines (DWV). Schedule 40 is residential standard.
- CPVC: rated for hot and cold water supply up to 200 degrees F and 100 PSI
- Solvent cement joints are permanent -- no mechanical connections to fail or loosen
- Lightweight and easy to cut with a hacksaw or PVC cutter
- Corrosion-proof, chemical-resistant, and unaffected by soil conditions (ideal for underground)
Sizing & Selection
DWV (PVC): 1-1/2 inch for sinks, 2 inch for showers and tubs, 3 inch or 4 inch for toilet waste and main stacks. Supply (CPVC): 3/4 inch for mains, 1/2 inch for branches. Schedule 40 is standard wall thickness for both. Schedule 80 (thicker wall) is used for commercial or high-pressure applications.
Installation
Cut square with a PVC cutter or fine-tooth saw. Deburr inside and outside. Dry-fit first to verify alignment. Apply primer (purple) to both pipe and fitting socket -- this softens the surface for chemical bonding. Apply cement (clear or gray) to both surfaces. Push together with a quarter twist and hold for 30 seconds. The joint is hand-strength solid in 2 minutes, full cure in 24 hours. Joints are permanent -- mistakes require cutting out and redoing.
Maintenance
- PVC and CPVC are essentially maintenance-free. No corrosion, no scaling.
- Inspect exposed runs for cracks, especially in cold garages or attics -- PVC becomes brittle in extreme cold.
- CPVC in hot water supply: check for discoloration or softening near the water heater outlet. Replace the first 18 inches with copper or braided connector.
- Support horizontal runs with hangers every 3-4 feet (PVC sags when warm if unsupported).
Buying Tips
- PVC for drains, CPVC for supply. Never use PVC for hot water supply.
- Always use primer before cement -- it is required by code in most areas and ensures a proper chemical bond.
- Buy the correct cement: PVC cement for PVC, CPVC cement for CPVC, or an all-purpose (orange) cement that works on both.
- Schedule 40 is standard. Do not buy Schedule 20 (thin-wall drain pipe) for anything structural or under pressure.
- PVC is the cheapest piping material available. A full house DWV system costs a fraction of cast iron or copper DWV.