Install PEX Water Lines — Run the Hot and Cold Water Supply Lines
Part of project
How to Rough-In Plumbing for a Bathroom Vanity · Step 5 of 8
In this video
The presenter prepares for and installs the PEX water supply lines. Using a drill with a 5/8-inch auger bit, he drills two holes through the wooden bottom plate of the wall, one for the hot and one for the cold line, aligning them below the corresponding inlets on the outlet box. He feeds the red and blue PEX pipes up through the holes. For each line, he slides a 1/2-inch stainless steel crimp ring onto the pipe. He then pushes the end of the PEX pipe fully onto the brass barb fitting of the valve. He positions the crimp ring about 1/8 of an inch from the base of the fitting. Using a PEX crimping tool, he squeezes the handles until the tool fully closes, which compresses the ring and secures the pipe to the fitting, creating a permanent, leak-proof connection. He repeats the process for the second water line.
Goal: Connect the hot and cold PEX water lines to the outlet box valves
- Ensure the PEX pipe is fully seated on the barb fitting before crimping the ring.
- Position the crimp ring 1/8 to 1/4 inch from the end of the pipe to allow for proper compression without damaging the fitting.
Used in this video
- Cordless Drill (brand: Ridgid, Tool Type: Power Tools, Power Source: Battery) — Drilling holes for the PEX pipes.
- Auger Drill Bit (brand: Unbranded, Material: Metal, Size/Dimensions: 5/8 inch) — Drilling clean holes in the wood frame.
- PEX Crimping Tool (brand: Unbranded, Tool Type: Hand Tools, Power Source: Manual) — Securing crimp rings onto PEX pipes and fittings.
- Pliers (brand: Unbranded, Tool Type: Hand Tools, Power Source: Manual) · optional — Temporarily holding the crimp ring in place before using the crimping tool.
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FAQs
How difficult is it to rough-in plumbing for a vanity, and how long should I expect it to take?
This project is rated "intermediate" because it requires precise measurements, proper pipe joining techniques, and an understanding of plumbing codes. For a DIYer with some experience, expect 8-16 hours of work, depending on existing wall access and any unforeseen issues. Costs can range from $150-$300 for materials, assuming you already own basic tools.
What are the most crucial safety precautions I should take when roughing-in plumbing?
Always shut off the main water supply before cutting into existing lines to prevent flooding. Wear appropriate personal protective equipment (PPE) like safety glasses, gloves, and hearing protection, especially when using power tools like drills and hole saws. Be mindful of electrical wires inside walls when drilling or cutting.
The guide mentions PEX for supply lines; can I use copper or CPVC instead, and what are the pros of PEX?
While copper and CPVC are alternatives, PEX is often preferred for DIY projects due to its flexibility, ease of installation (fewer fittings, no soldering), and resistance to freezing. However, PEX requires specific crimp or expansion tools. If you're comfortable with soldering, copper is a durable choice, and CPVC offers a rigid, solvent-weld option.
What are the most common mistakes DIYers make when roughing-in a vanity's drain and supply lines?
A common mistake is incorrect drain slope, leading to clogs – ensure a 1/4 inch per foot slope for DWV lines. Another error is misplacing supply stub-outs, making fixture installation difficult; always double-check vanity and sink specifications. Also, failing to properly prime and cement PVC joints can cause leaks.
Install PEX Water Lines — Run the Hot and Cold Water Supply Lines
Part of project
How to Rough-In Plumbing for a Bathroom Vanity · Step 5 of 8
In this video
The presenter prepares for and installs the PEX water supply lines. Using a drill with a 5/8-inch auger bit, he drills two holes through the wooden bottom plate of the wall, one for the hot and one for the cold line, aligning them below the corresponding inlets on the outlet box. He feeds the red and blue PEX pipes up through the holes. For each line, he slides a 1/2-inch stainless steel crimp ring onto the pipe. He then pushes the end of the PEX pipe fully onto the brass barb fitting of the valve. He positions the crimp ring about 1/8 of an inch from the base of the fitting. Using a PEX crimping tool, he squeezes the handles until the tool fully closes, which compresses the ring and secures the pipe to the fitting, creating a permanent, leak-proof connection. He repeats the process for the second water line.
Goal: Connect the hot and cold PEX water lines to the outlet box valves
- Ensure the PEX pipe is fully seated on the barb fitting before crimping the ring.
- Position the crimp ring 1/8 to 1/4 inch from the end of the pipe to allow for proper compression without damaging the fitting.
Used in this video
- Cordless Drill (brand: Ridgid, Tool Type: Power Tools, Power Source: Battery) — Drilling holes for the PEX pipes.
- Auger Drill Bit (brand: Unbranded, Material: Metal, Size/Dimensions: 5/8 inch) — Drilling clean holes in the wood frame.
- PEX Crimping Tool (brand: Unbranded, Tool Type: Hand Tools, Power Source: Manual) — Securing crimp rings onto PEX pipes and fittings.
- Pliers (brand: Unbranded, Tool Type: Hand Tools, Power Source: Manual) · optional — Temporarily holding the crimp ring in place before using the crimping tool.
Frequently Asked Questions
How difficult is it to rough-in plumbing for a vanity, and how long should I expect it to take?
This project is rated "intermediate" because it requires precise measurements, proper pipe joining techniques, and an understanding of plumbing codes. For a DIYer with some experience, expect 8-16 hours of work, depending on existing wall access and any unforeseen issues. Costs can range from $150-$300 for materials, assuming you already own basic tools.
What are the most crucial safety precautions I should take when roughing-in plumbing?
Always shut off the main water supply before cutting into existing lines to prevent flooding. Wear appropriate personal protective equipment (PPE) like safety glasses, gloves, and hearing protection, especially when using power tools like drills and hole saws. Be mindful of electrical wires inside walls when drilling or cutting.
The guide mentions PEX for supply lines; can I use copper or CPVC instead, and what are the pros of PEX?
While copper and CPVC are alternatives, PEX is often preferred for DIY projects due to its flexibility, ease of installation (fewer fittings, no soldering), and resistance to freezing. However, PEX requires specific crimp or expansion tools. If you're comfortable with soldering, copper is a durable choice, and CPVC offers a rigid, solvent-weld option.
What are the most common mistakes DIYers make when roughing-in a vanity's drain and supply lines?
A common mistake is incorrect drain slope, leading to clogs – ensure a 1/4 inch per foot slope for DWV lines. Another error is misplacing supply stub-outs, making fixture installation difficult; always double-check vanity and sink specifications. Also, failing to properly prime and cement PVC joints can cause leaks.