Mount the Outlet Box — Install Drain and Vent Assembly
Part of project
How to Rough-In Plumbing for a Bathroom Vanity · Step 3 of 5
In this video
With the P-trap installed, the presenter prepares to mount the outlet box. He measures from the subfloor up to 43 inches and makes a mark on the stud to indicate the bottom of the outlet box. He measures the distance from the top of the P-trap to his mark to determine the length of the vertical PVC pipe needed. After cutting the pipe, he applies primer and cement to the P-trap and the pipe, then installs the vertical pipe. He then applies primer and cement to the top of the vertical pipe and the drain port on the outlet box. He pushes the box down onto the pipe with a twisting motion and holds it. He marks the pipe and box for alignment. After the glue sets, he re-installs the plastic mounting straps onto the box. He then secures the straps to the adjacent 2x4 studs using drywall screws and an impact driver, ensuring the box is firmly in place and level.
Goal: Securely mount the washing machine outlet box to the drain pipe and wall studs
- Dry-fitting the outlet box before gluing is crucial to ensure you cut the drain pipe to the perfect length.
- Marking the pipe and the box before gluing helps ensure you line them up correctly for a square and level installation.
Used in this video
- Tape Measure (brand: Unbranded, Tool Type: Measuring Tools, Power Source: Manual) — Measuring the height for the outlet box and the length of the PVC pipe.
- Pencil (brand: Unbranded, Tool Type: Hand Tools, Power Source: Manual) — Marking measurements on studs and pipes.
- Impact Driver (brand: Ridgid, Tool Type: Power Tools, Power Source: Battery) — Driving screws to secure the mounting straps to the studs.
- Drywall Screws (brand: Unbranded, Material: Metal) — Fastening the mounting straps to the wood studs.
729K subscribers
FAQs
As an "intermediate" project, how challenging is roughing in plumbing for someone with limited prior plumbing experience?
While intermediate, this project requires precision for proper drain slope, watertight PEX connections, and adherence to plumbing codes. Take your time, double-check all measurements and connections, and be prepared to consult diagrams and local regulations. Mistakes in plumbing can be very costly to fix later.
Do I need all the specialized tools listed, like the PEX crimp tool and specific tubing cutters, or are there more budget-friendly alternatives?
Specialized PEX tools are highly recommended for reliable, leak-free connections that meet code. While some PEX systems offer push-to-connect fittings, traditional crimping or expansion tools provide a more robust rough-in. Renting expensive tools like PEX crimpers can be a cost-effective alternative for a one-time project.
Is it always necessary to get a permit and have an inspection for new plumbing rough-in work like this bathroom vanity?
Yes, new plumbing installations almost always require permits and inspections to ensure safety and compliance with local building codes. Failing to obtain permits can lead to costly rework, fines, or issues when selling your home. Always check with your local building department before starting any plumbing work.
What are the most common mistakes DIYers make during a plumbing rough-in, and how can I avoid them, especially regarding leaks?
Common mistakes include improper drain slope leading to clogs, poorly sealed DWV joints, and incorrect PEX connections causing leaks. To avoid these, ensure all PVC joints are dry-fitted and then properly cemented, and that PEX connections are correctly crimped/expanded and burr-free. Always pressure-test the system thoroughly before closing the wall.
Mount the Outlet Box — Install Drain and Vent Assembly
Part of project
How to Rough-In Plumbing for a Bathroom Vanity · Step 3 of 5
In this video
With the P-trap installed, the presenter prepares to mount the outlet box. He measures from the subfloor up to 43 inches and makes a mark on the stud to indicate the bottom of the outlet box. He measures the distance from the top of the P-trap to his mark to determine the length of the vertical PVC pipe needed. After cutting the pipe, he applies primer and cement to the P-trap and the pipe, then installs the vertical pipe. He then applies primer and cement to the top of the vertical pipe and the drain port on the outlet box. He pushes the box down onto the pipe with a twisting motion and holds it. He marks the pipe and box for alignment. After the glue sets, he re-installs the plastic mounting straps onto the box. He then secures the straps to the adjacent 2x4 studs using drywall screws and an impact driver, ensuring the box is firmly in place and level.
Goal: Securely mount the washing machine outlet box to the drain pipe and wall studs
- Dry-fitting the outlet box before gluing is crucial to ensure you cut the drain pipe to the perfect length.
- Marking the pipe and the box before gluing helps ensure you line them up correctly for a square and level installation.
Used in this video
- Tape Measure (brand: Unbranded, Tool Type: Measuring Tools, Power Source: Manual) — Measuring the height for the outlet box and the length of the PVC pipe.
- Pencil (brand: Unbranded, Tool Type: Hand Tools, Power Source: Manual) — Marking measurements on studs and pipes.
- Impact Driver (brand: Ridgid, Tool Type: Power Tools, Power Source: Battery) — Driving screws to secure the mounting straps to the studs.
- Drywall Screws (brand: Unbranded, Material: Metal) — Fastening the mounting straps to the wood studs.
Frequently Asked Questions
As an "intermediate" project, how challenging is roughing in plumbing for someone with limited prior plumbing experience?
While intermediate, this project requires precision for proper drain slope, watertight PEX connections, and adherence to plumbing codes. Take your time, double-check all measurements and connections, and be prepared to consult diagrams and local regulations. Mistakes in plumbing can be very costly to fix later.
Do I need all the specialized tools listed, like the PEX crimp tool and specific tubing cutters, or are there more budget-friendly alternatives?
Specialized PEX tools are highly recommended for reliable, leak-free connections that meet code. While some PEX systems offer push-to-connect fittings, traditional crimping or expansion tools provide a more robust rough-in. Renting expensive tools like PEX crimpers can be a cost-effective alternative for a one-time project.
Is it always necessary to get a permit and have an inspection for new plumbing rough-in work like this bathroom vanity?
Yes, new plumbing installations almost always require permits and inspections to ensure safety and compliance with local building codes. Failing to obtain permits can lead to costly rework, fines, or issues when selling your home. Always check with your local building department before starting any plumbing work.
What are the most common mistakes DIYers make during a plumbing rough-in, and how can I avoid them, especially regarding leaks?
Common mistakes include improper drain slope leading to clogs, poorly sealed DWV joints, and incorrect PEX connections causing leaks. To avoid these, ensure all PVC joints are dry-fitted and then properly cemented, and that PEX connections are correctly crimped/expanded and burr-free. Always pressure-test the system thoroughly before closing the wall.