Tired of a cramped double sink that wastes counter space and complicates your kitchen workflow? You’re not alone. Many U.S. homeowners are simplifying their kitchens by converting from a double sink to a single sink—boosting usability, aesthetics, and even resale value. If you’re wondering how to change plumbing from double sink to single sink, this guide walks you through every step with clarity, safety, and expert-backed tips. Whether you’re a weekend DIYer or planning a full kitchen refresh, you’ll gain the confidence to tackle this project right.
Why Convert from a Double Sink to a Single Sink?
Before diving into the “how,” it helps to understand the “why.” According to the National Kitchen & Bath Association (NKBA), 68% of modern kitchen remodels now feature a single-bowl sink, citing improved functionality for large pots, easier cleaning, and streamlined countertop design.
Common reasons homeowners make the switch:
More usable counter space – A single sink frees up room for food prep or appliances.
Easier maintenance – No divider means fewer nooks for grime.
Modern aesthetic – Sleek, minimalist sinks align with current design trends.
Better plumbing efficiency – One drain and faucet reduce potential leak points.
What Tools and Materials Will You Need?
Converting your sink isn’t just about swapping fixtures—it’s about rerouting plumbing correctly. Here’s your checklist:
New single sink (ensure it fits your cabinet cutout)
New faucet (if not reusing)
P-trap and tailpiece (often included with sink)
PVC or ABS pipes (1½-inch diameter standard for sinks)
Compression fittings or slip nuts
💡 Pro Tip: Always shut off the water supply valves under the sink before starting. If valves are missing or corroded, shut off the main water line.
Step-by-Step Guide: How to Change Plumbing from Double Sink to Single Sink
Follow these steps carefully to avoid leaks, water damage, or code violations.
Step 1: Remove the Old Double Sink
Turn off hot and cold water supply lines.
Disconnect supply lines using an adjustable wrench.
Place a bucket under the P-trap and unscrew it to drain residual water.
Loosen mounting clips or brackets holding the sink in place.
Carefully lift out the double sink—have a helper if it’s heavy stone or cast iron.
Step 2: Cap or Remove Unused Drain and Supply Lines
Since you’re going from two basins to one, you’ll have one set of unused plumbing. You have two options:
Cap the unused lines (recommended if you might revert later).
Remove and reroute pipes for a cleaner setup (ideal for permanent changes).
Use threaded caps for supply lines and PVC caps with glue for drain lines. Ensure all caps are rated for plumbing use.
📌 Note: Local plumbing codes vary. In most U.S. jurisdictions, capped lines must remain accessible—don’t bury them behind drywall without an access panel.
Step 3: Prepare the Countertop for the New Sink
Measure your new single sink’s dimensions.
If your countertop cutout is too large, you may need an apron-front sink or custom filler panels.
Clean the surface thoroughly and remove old sealant residue.
Step 4: Install the New Single Sink
Apply a bead of plumber’s putty or silicone around the sink flange.
Lower the sink into place, ensuring it’s centered and level.
Secure with mounting clips underneath (typically 4–6 clips).
Wipe away excess sealant.
Step 5: Reconnect Plumbing
Attach the new faucet (if replacing) before connecting water lines.
Connect hot and cold supply lines to the faucet tailpieces.
Install the new P-trap assembly, connecting it to the single drain and the main waste pipe.
Ensure all connections are hand-tightened, then give a quarter-turn with a wrench—over-tightening causes cracks.
Step 6: Test for Leaks
Turn water supply back on.
Run both hot and cold water for 2–3 minutes.
Check all joints, valves, and the P-trap for drips.
Look under the sink with a flashlight—small leaks are easy to miss.
If you spot a leak, turn off the water and re-tighten or reseal the connection.
Double Sink vs. Single Sink: Pros and Cons
Space Efficiency
Divides counter; limits large items
Maximizes usable area
Cleaning Ease
Hard-to-reach divider corners
One open basin = easier scrubbing
Plumbing Complexity
Two drains, two faucets (or shared)
Simpler setup, fewer failure points
Resale Appeal
Traditional; preferred in some markets
Trending in modern homes
Water Usage
Potentially higher (two basins)
Often more efficient
According to a 2024 Houzz Kitchen Trends Study, single sinks are now preferred by 61% of renovating homeowners under 45, signaling a clear shift in user intent toward simplicity and function.
Reusing old P-traps: Corroded or misaligned traps cause slow drainage or odors.
Skipping the leak test: Even a small drip can cause mold or cabinet damage over time.
Mismatched sink cutouts: Measure twice—custom countertops may require professional help.
FAQ Section
Q1: Can I reuse my existing faucet when switching to a single sink?
A: Yes, if the faucet’s mounting configuration matches your new sink (e.g., single-hole, 4-inch centerset). However, many homeowners upgrade to a modern pull-down faucet during this conversion for better functionality.
Q2: Do I need a plumber to change from double to single sink?
A: Not necessarily. If you’re comfortable with basic plumbing and follow safety steps, this is a manageable DIY project. However, if you’re rerouting pipes inside walls or lack shutoff valves, hiring a licensed plumber is wise.
Q3: Will this conversion affect my home’s resale value?
A: Generally, yes—in a positive way. Modern buyers favor open, functional kitchens. Just ensure the installation is clean, code-compliant, and leak-free.
Q4: How long does the conversion take?
A: Most DIYers complete it in 3–6 hours. Allow extra time if you’re also replacing the countertop or faucet.
Q5: Can I convert back to a double sink later?
A: Yes, especially if you capped (rather than removed) the second set of lines. Keep capped pipes accessible for future changes.
Q6: What size single sink should I choose?
A: Standard single sinks range from 30 to 36 inches wide. Measure your cabinet interior—leave at least 3 inches on each side for mounting. For small kitchens, consider a 27-inch model.
Conclusion
Knowing how to change plumbing from double sink to single sinkempowers you to create a kitchen that’s not only stylish but truly functional. With the right tools, a methodical approach, and attention to plumbing best practices, you can complete this upgrade confidently—saving money on labor and boosting your home’s appeal.
If this guide helped you, share it with a friend tackling their own kitchen project! Got questions? Drop them in the comments below—we love helping DIYers succeed.
And remember: great kitchens start with smart plumbing. 💧🔧
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