What tools do I need for rough-in plumbing for a new bathroom?

This guide includes a comprehensive tools list. Key plumbing tools are detailed in the Tools Required section.

What is the Australian standard for bathroom plumbing installations?

The primary Australian standard for bathroom plumbing installations is AS/NZS 3500, specifically AS/NZS 3500.1:2021 for water services and AS/NZS 3500.2:2021 for sanitary plumbing and drainage. These standards, along with the Plumbing Code of Australia (PCA), dictate requirements for pipe sizing, materials, installation methods, and testing. Adherence is mandatory for all licensed plumbers.

How to rough-in plumbing for a new bathroom

This guide details the process of roughing-in plumbing for a new bathroom in Australia, covering the essential steps for waste, water supply, and fixture connections. Precise planning and adherence to the Plumbing Code of Australia (PCA) and AS/NZS 3500 are critical for a compliant and functional in

Skill level: Intermediate
Time: 1-3 days (depending on bathroom size and complexity)
Trade: Plumbing
Updated: 4 November 2026

Tools you will need

Tape Measure: 8m or 10m for accurate set
Pipe Cutters:
Deburring Tool: For copper and PVC pipe ends.
Crimping/Press
Soldering Torch Kit:
Adjustable Spanners/Wrenches: For tightening fittings.
Pipe Benders:
Chisels/Hammer: For minor timber notching
Caulking Gun: For applying silicone sealant.

What is involved in rough-in plumbing for a new bathroom in Australia?

What skill level is required for rough-in plumbing a new bathroom?

Intermediate — Estimated time: 1-3 days (depending on bathroom size and complexity)

What essential tools are needed for rough-in plumbing a new bathroom?

Tape Measure: 8m or 10m for accurate set-out. Spirit Level: 600mm and 1200mm for ensuring correct fall and horizontal alignment. Marker Pen/Pencil: For marking pipe runs and fixture locations. Pipe Cutters: Copper Pipe Cutter: For 15mm, 20mm, 25mm copper. PEX/HDPE Pipe Shears: For 16mm, 20mm, 25mm PEX/HDPE. PVC Pipe Cutter/Saw: For 40mm, 50mm, 65mm, 80mm, 100mm PVC. Deburring Tool: For copper and PVC pipe ends. Crimping/Press-Fit Tool: Specific to the chosen PEX or copper press-fit system (e.g., Viega, Kembla, Auspex). Soldering Torch Kit: (If using copper braze/solder joints) Propane/MAP-Pro torch, flux, solder. Drill: Cordless or corded, with various sized hole saws and spade bits for timber studs/joists. Adjustable Spanners/Wrenches: For tightening fittings. Pipe Benders: (If using copper) Spring or lever benders for 15mm and 20mm. Chisels/Hammer: For minor timber notching (ensure structural integrity is maintained). Caulking Gun: For applying silicone sealant. Safety Glasses, Gloves, Hearing Protection: Essential PPE.

What materials are typically required for rough-in bathroom plumbing?

Water Supply Pipe: Copper: 15mm and 20mm Type B or C (AS 1432). PEX: 16mm and 20mm (AS/NZS 2492) with appropriate crimp/press fittings. HDPE: 20mm and 25mm (AS/NZS 4130) with electrofusion or compression fittings. Drainage Pipe: PVC-U: 40mm, 50mm, 65mm, 80mm, 100mm DWV (AS/NZS 1260). Fittings: Water Supply: Elbows, tees, reducers, stopcocks, male/female adaptors specific to chosen pipe material. Drainage: Elbows (sweep and standard), tees, junctions, reducers, P-traps, floor wastes (grated). Pipe Clips/Brackets: Appropriate for pipe size and material (e.g., plastic clips for PEX/PVC, copper clips for copper). Pipe Insulation: For hot water lines (AS/NZS 3500.4). PVC Primer and Solvent Cement: For PVC DWV joints (AS/NZS 3879). Thread Seal Tape (PTFE): For threaded connections. Timber Noggins/Blocking: For securing fixture points. Waterproofing Membrane: (To be applied by a licensed waterproofer, but consider pipe penetration details). Temporary Caps/Plugs: For pressure testing and preventing debris ingress.

Safety Requirements

⚠️ Always wear appropriate Personal Protective Equipment (PPE): Safety glasses, gloves, and hearing protection. ⚠️ Hot Work: If soldering, ensure adequate ventilation, have a fire extinguisher nearby, and protect surrounding combustible materials. ⚠️ Electrical Safety: Be aware of existing electrical wiring within walls/ceilings. Isolate power if working near electrical circuits. ⚠️ Structural Integrity: Do not cut or notch structural timber (studs, joists, beams) without engineering approval. Use appropriate drilling techniques to avoid weakening structures. ⚠️ Confined Spaces: Ensure adequate ventilation if working in confined areas. ⚠️ Pressure Testing: Always follow safe procedures for pressure testing water lines. ⚠️ Gas Lines: This guide does not cover gas fitting. Gas work requires a separate, licensed gas fitter.

Step-by-Step Guide

Step 1: 1️⃣ Plan and Mark Out Fixture Locations

Plumbing work in Australia must be performed by a licensed plumber. This guide explains the process and helps you select the right tools and materials.
Review Plans: Carefully study architectural and plumbing plans to confirm exact locations of toilet, basin, shower, and bath. Measure and Mark: Use your tape measure and spirit level to accurately mark the centre lines and heights for all fixtures on the stud walls and subfloor. Toilet: Waste outlet typically 100mm DWV at 185mm-230mm from finished wall (P-trap) or 100mm from finished wall (S-trap). Water supply at 150mm-200mm above finished floor, 150mm-200mm off centre. Basin: Waste outlet 40mm or 50mm DWV at 500mm-600mm above finished floor. Hot and cold water supply at 600mm-700mm above finished floor, 100mm-150mm apart. Shower: Waste outlet 50mm or 80mm DWV floor waste. Hot and cold water supply at 800mm-1000mm above finished floor, 150mm apart. Bath: Waste outlet 40mm or 50mm DWV floor waste. Hot and cold water supply at 600mm-700mm above finished floor, 150mm apart (if wall-mounted spout) or below rim for deck-mounted. Consider Wall Thickness: Account for plasterboard, tiles, and waterproofing when marking out.

Step 2: 2️⃣ Install Drainage Rough-in

Main Stack Connection: Connect the new bathroom's main waste line to the existing sewer stack or main drain line, ensuring correct fall. Toilet Waste: Install the 100mm DWV pipe for the toilet, ensuring it's correctly aligned with the marked centre and height. Secure with clips. Shower Waste: Install the 50mm or 80mm DWV pipe for the shower floor waste, ensuring it's flush with the subfloor and has adequate fall to the main waste line. Basin Waste: Run 40mm or 50mm DWV pipe from the marked basin waste point to the main waste line, ensuring correct fall. Bath Waste: Run 40mm or 50mm DWV pipe for the bath waste, ensuring it's positioned correctly for the bath trap and has adequate fall. Ventilation: Ensure all fixtures are correctly vented according to AS/NZS 3500.2 to prevent trap siphonage. Joinery: Use PVC primer and solvent cement for all PVC DWV joints, ensuring a strong, watertight seal. 💡 Pro Tip: Use sweep bends for changes in direction on horizontal runs to improve flow and reduce blockages.

Step 3: 3️⃣ Install Water Supply Rough-in

Main Isolation: Ensure the main water supply to the property is isolated before commencing work. Run Hot & Cold Lines: Run 20mm or 25mm main hot and cold water lines from the existing supply points (or hot water unit) to the bathroom. Branch Lines: Branch off with 15mm or 16mm pipe to each fixture (toilet, basin, shower, bath). Secure Pipework: Secure all pipework with appropriate clips or brackets every 600mm horizontally and 1000mm vertically, ensuring no movement. Noggins/Blocking: Install timber noggins between studs at the correct height for securing fixture points (e.g., shower mixer, basin taps). Stub-outs: Terminate water lines with appropriate male/female adaptors or stopcocks, ensuring they protrude sufficiently from the finished wall/floor for connection to fixtures. Cap all open ends temporarily. Insulation: Insulate all hot water lines to minimise heat loss, as per AS/NZS 3500.4. 💡 Pro Tip: Plan pipe runs to minimise joints and avoid unnecessary bends, which can reduce pressure.

Step 4: 4️⃣ Install In-Wall Fixture Components

Shower Mixer: Install the shower mixer body at the marked height, ensuring it is plumb and level. Secure it firmly to the timber noggin. Bath Mixer/Spout: Install the bath mixer body or spout rough-in, securing it to noggins. Toilet Cistern (if in-wall): Install the in-wall cistern frame and pan connector, ensuring it's level, plumb, and at the correct height for the chosen toilet pan. Backflow Prevention: Install backflow prevention devices where required by AS/NZS 3500.1 (e.g., for bidet sprays, some outdoor taps). Tempering Valve: If the hot water system delivers water above 50°C (e.g., storage systems), install a tempering valve to ensure hot water delivered to sanitary fixtures does not exceed 50°C, as per AS/NZS 3500.4 and state regulations.

Step 5: 5️⃣ Pressure Testing and Inspection
Water Supply: Once all water lines are installed and capped, pressure test the system to 1500 kPa for a minimum of 30 minutes (or as per local authority requirements). Check for any leaks at joints. Drainage: Temporarily plug all drainage outlets and fill the system with water to check for leaks. Ensure all traps hold water. Visual Inspection: Conduct a thorough visual inspection of all pipework for correct fall, secure fixings, and compliance with plans and standards. Council/Certifier Inspection: Arrange for the mandatory rough-in inspection by the local council or private certifier before walls are closed up. This is a critical compliance step. 🔒 Licensing: Plumbing work in Australia must be performed by a licensed plumber. State licensing bodies (e.g., NSW Fair Trading, VIC VBA, QLD QBCC, WA Building Commission) oversee compliance.

Common Mistakes to Avoid

1.Incorrect Fall on Drainage: Not enough fall (minimum 1:60 for 100mm DWV, 1:80 for 40mm/50mm DWV) leads to blockages. Too much fall can cause water to outrun solids.

2.Inadequate Support: Pipes not properly clipped or supported can sag, create noise, or lead to premature failure.

3.Structural Damage: Cutting or notching timber studs/joists without understanding structural implications can compromise building integrity.

4.Incorrect Stub-out Lengths: Water supply stub-outs too short or too long, making fixture installation difficult or impossible without re-work.

5.Forgetting Tempering Valves: Failing to install a tempering valve where required, leading to scalding risk and non-compliance.

6.No Pressure Test: Skipping pressure testing, resulting in hidden leaks behind finished walls.

Pro Tips

💡 Dry Fit First: For complex PVC drainage runs, dry fit components before cementing to ensure correct alignment and fall. 💡 Colour Code: Use red and blue insulation or tape to clearly mark hot and cold water lines, especially in busy wall cavities. 💡 Access Panels: Plan for future access panels for in-wall cisterns, tempering valves, or other components that may require maintenance. 💡 Waterproofing Details: Coordinate with the waterproofer regarding pipe penetrations through floor and wall sheeting to ensure a watertight seal. Use appropriate pipe collars or flanges. 💡 WELS Ratings: Advise clients on fixtures with high WELS (Water Efficiency Labelling and Standards) star ratings to promote water efficiency. A 4-star WELS showerhead uses significantly less water than a 2-star. 💡 Photo Documentation: Take clear photos of all rough-in plumbing before walls are closed up. This is invaluable for future reference or fault finding.

Recommended Tools

Milwaukee M18 FORCE LOGIC Press Tool: For

Frequently asked questions

What is involved in rough-in plumbing for a new bathroom?: This guide details the process of roughing-in plumbing for a new bathroom in Australia, covering the essential steps for waste, water supply, and fixture connections. Precise planning and adherence to the Plumbing Code of Australia (PCA) and AS/NZS 3500 are critical for a compliant and functional in
What skill level do I need for rough-in plumbing for a new bathroom?: Intermediate — Estimated time: 1-3 days (depending on bathroom size and complexity)
What are common mistakes when rough-in plumbing for a new bathroom?: 1. Incorrect Fall on Drainage: Not enough fall (minimum 1:60 for 100mm DWV, 1:80 for 40mm/50mm DWV) leads to blockages. Too much fall can cause water to outrun solids. 2. Inadequate Support: Pipes not properly clipped or supported can sag, create noise, or lead to premature failure. 3. Structural Damage: Cutting or notching timber studs/joists without understanding struc
What tools do I need for rough-in plumbing for a new bathroom?: This guide includes a comprehensive tools list. Key plumbing tools are detailed in the Tools Required section.
What is the Australian standard for bathroom plumbing installations?: The primary Australian standard for bathroom plumbing installations is AS/NZS 3500, specifically AS/NZS 3500.1:2021 for water services and AS/NZS 3500.2:2021 for sanitary plumbing and drainage. These standards, along with the Plumbing Code of Australia (PCA), dictate requirements for pipe sizing, materials, installation methods, and testing. Adherence is mandatory for all licensed plumbers.

Written by Pipey, the Plumbing specialist at Aus.Tools.