Plumbing Plans (P Sheets) Cheat Sheet
Your Extended Reference Guide for Navigating Plumbing Drawings
1. What P Sheets Include
- Plumbing Floor Plans
- Riser Diagrams (Sanitary, Waste, Vent, and Water)
- Fixture Connection Diagrams
- Isometric Diagrams
- Plumbing Schedules (Fixtures, Piping)
- General Notes & Installation Requirements
- Pipe Sizing and Material Specifications
2. How to Navigate P Sheets
- Start with floor plans to locate fixture symbols and pipe routing
- Use riser diagrams to trace vertical pipe routing floor-by-floor
- Isometrics show relationships between pipes in 3D format
- Review fixture schedule for rough-in sizes, heights, and types
- Cross-check pipe materials and insulation notes in the general notes
Always compare P sheets with A sheets to match fixture locations and quantities
3. Key Symbols & Legends
- Cold Water: Blue or CW symbol
- Hot Water: Red or HW symbol
- Waste/Vent: Solid or dashed lines with labels (W, V, S)
- Risers: Arrows indicating up/down movement (UP, DN)
- Fixtures: Tagged with numbers tied to a schedule (P-1, P-2, etc.)
4. Tips for Estimators & Contractors
- Use floor plan and riser together for complete takeoff
- Trace each pipe by system (CW, HW, DWV, gas)
- Count all fixtures, valves, cleanouts, and hangers
- Verify elevation changes for underground vs. above-ceiling piping
- Double-check ADA fixture heights and clearances
Use color-coded overlays when estimating each pipe system
5. Common Mistakes to Avoid
- Missing vertical pipes shown only in risers
- Forgetting isolation valves and floor drains
- Not accounting for insulation on hot water piping
- Using the wrong fixture units or flow rates
- Assuming pipe size instead of verifying in diagrams