🔎 Symbols & Plan Notes

• Demo walls: cross-hatched or shaded, tagged with "D".
• Demo doors/windows: dashed swing outlines or "remove" cloud notes.
• Floor/ceiling demo: dashed grid lines with keynote callouts.
• Equipment/furniture demo: dashed symbols with “EXIST TO BE REMOVED”.
• Selective demo: leaders + cloud tags → e.g., “REMOVE TILE ONLY, KEEP SLAB”.
• Hazard notes: abatement callouts for asbestos, lead, PCB, etc.

📐 Estimating & Takeoffs

• Wall demo: length × height = SF of demo surface (drywall, CMU, partitions).
• Slab removal: length × width × thickness ÷ 27 = CY of concrete to haul.
• Roof removal: roof area ÷ 100 = squares → disposal volume estimate.
• Fixture removal: count from plans/schedules (sinks, toilets, lights, ducts).
• Debris hauling: 1 CY ≈ 600 lb concrete; 1 CY ≈ 300 lb drywall; 20–30 CY dumpster holds ~5–7 tons.
• Soft demo (interiors): labor-intensive — often priced per SF (verify crew rates).

📋 Sequencing & Field Notes

• 🔌 Shut down utilities: disconnect power, gas, water, telecom before demo.
• 🧯 Fire protection: cap sprinklers, install temp protection if needed.
• 🚪 Selective demo: brace adjacent finishes, avoid damage to retained work.
• 🏗️ Structural: confirm shoring before removing load-bearing walls/slabs.
• 🪣 Waste streams: separate concrete, steel, drywall, wood for recycling (LEED credits possible).
• 📝 Documentation: photos, as-builts for unforeseen conditions.

🦺 Safety First

• Asbestos/lead survey required before disturbance.
• Dust control: water spray, negative air, containment.
• Fall protection: edges, roof demo, open shafts.
• Noise/vibration limits per local ordinance.
• OSHA Subpart T: demolition standard — hazard assessments required.
• PPE: respirators, gloves, eye/ear protection.
• Rigging & equipment safety: ensure trained operators for demo machines.

📝 Self Test

1. How many CY of debris from a 30' × 40' slab at 6" thick?
2. What does “D” in a clouded plan callout usually indicate?
3. How many dumpsters (30 CY) are needed for 90 CY of concrete demo?
4. What is the OSHA subpart that governs demolition?
5. What must be done before removing a load-bearing wall?

Answers: (1) 30×40×0.5 ÷ 27 ≈ 22.2 CY, (2) Demo item, (3) 90 ÷ 30 = 3 dumpsters, (4) Subpart T, (5) Provide shoring/structural support).