Remove Old Valve and Install New Valve Body — Run Water Supply Lines
Part of project
How to Rough-In Plumbing for a Basement Bathroom · Step 6 of 7
In this video
With the water supply shut off, the old three-handle valve and its connected galvanized pipes are cut out and removed from the wall cavity. New PEX tubing is run from the existing hot and cold water supply lines. The new Moen single-handle valve body is securely mounted inside the wall. The PEX supply lines are then connected to the hot and cold inlets on the valve using threaded adapters. A new galvanized pipe is installed for the shower riser, connecting to the top outlet of the valve. For the tub spout, a short piece of copper pipe with a 90-degree elbow is connected to the bottom outlet of the valve. PTFE tape is used on all threaded connections to ensure a leak-proof seal.
Goal: Install new shower valve body
- Ensure the valve is installed squarely and securely. An improperly mounted valve can lead to trim kit installation issues and potential leaks.
- Connect the hot supply to the left inlet and the cold supply to the right inlet of the valve, which is the standard configuration.
Used in this video
- Reciprocating Saw — Cutting out old galvanized pipes.
- Pipe Wrench — Gripping and turning pipes and fittings.
- PEX Tool — Creating secure connections with PEX tubing (e.g., crimping or expanding).
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FAQs
How difficult is roughing in basement bathroom plumbing for a DIYer, and how long does it typically take?
This project is rated intermediate due to the need for precise measurements, concrete work, and understanding plumbing codes. For an experienced DIYer, it can take 3-5 full days of work, not including permit acquisition and inspection wait times. Beginners should consider professional help for critical steps like concrete cutting and main line tie-ins.
What permits do I need, and how do I ensure my rough-in plumbing passes inspection?
You will almost certainly need a plumbing permit and possibly a building permit. Contact your local building department early in the planning phase to understand all requirements, necessary inspections (like the rough-in inspection), and specific code regulations for pipe sizing, slope, and venting to avoid costly rework.
What's the best way to break up the concrete floor, and what safety precautions should I take?
A demolition hammer or electric jackhammer is highly recommended for efficiency, which can often be rented. Wear heavy-duty work gloves, steel-toed boots, eye protection, hearing protection, and a dust mask to protect against concrete dust and flying debris. Be mindful of existing utility lines marked during the planning phase.
What are the most common mistakes when installing the underground DWV pipes, and how can I avoid them?
Common mistakes include incorrect pipe slope, inadequate solvent welding, and insufficient depth for drain lines. Ensure a consistent slope of at least 1/4 inch per foot for proper drainage, use proper primer and cement for strong, leak-free joints, and confirm all pipes are securely bedded in gravel to prevent shifting.
Remove Old Valve and Install New Valve Body — Run Water Supply Lines
Part of project
How to Rough-In Plumbing for a Basement Bathroom · Step 6 of 7
In this video
With the water supply shut off, the old three-handle valve and its connected galvanized pipes are cut out and removed from the wall cavity. New PEX tubing is run from the existing hot and cold water supply lines. The new Moen single-handle valve body is securely mounted inside the wall. The PEX supply lines are then connected to the hot and cold inlets on the valve using threaded adapters. A new galvanized pipe is installed for the shower riser, connecting to the top outlet of the valve. For the tub spout, a short piece of copper pipe with a 90-degree elbow is connected to the bottom outlet of the valve. PTFE tape is used on all threaded connections to ensure a leak-proof seal.
Goal: Install new shower valve body
- Ensure the valve is installed squarely and securely. An improperly mounted valve can lead to trim kit installation issues and potential leaks.
- Connect the hot supply to the left inlet and the cold supply to the right inlet of the valve, which is the standard configuration.
Used in this video
- Reciprocating Saw — Cutting out old galvanized pipes.
- Pipe Wrench — Gripping and turning pipes and fittings.
- PEX Tool — Creating secure connections with PEX tubing (e.g., crimping or expanding).
Frequently Asked Questions
How difficult is roughing in basement bathroom plumbing for a DIYer, and how long does it typically take?
This project is rated intermediate due to the need for precise measurements, concrete work, and understanding plumbing codes. For an experienced DIYer, it can take 3-5 full days of work, not including permit acquisition and inspection wait times. Beginners should consider professional help for critical steps like concrete cutting and main line tie-ins.
What permits do I need, and how do I ensure my rough-in plumbing passes inspection?
You will almost certainly need a plumbing permit and possibly a building permit. Contact your local building department early in the planning phase to understand all requirements, necessary inspections (like the rough-in inspection), and specific code regulations for pipe sizing, slope, and venting to avoid costly rework.
What's the best way to break up the concrete floor, and what safety precautions should I take?
A demolition hammer or electric jackhammer is highly recommended for efficiency, which can often be rented. Wear heavy-duty work gloves, steel-toed boots, eye protection, hearing protection, and a dust mask to protect against concrete dust and flying debris. Be mindful of existing utility lines marked during the planning phase.
What are the most common mistakes when installing the underground DWV pipes, and how can I avoid them?
Common mistakes include incorrect pipe slope, inadequate solvent welding, and insufficient depth for drain lines. Ensure a consistent slope of at least 1/4 inch per foot for proper drainage, use proper primer and cement for strong, leak-free joints, and confirm all pipes are securely bedded in gravel to prevent shifting.