Kitchen Sink Plumbing Rough-In for Absolute Beginners

Installing the plumbing when renovating a kitchen can be an intimidating task, especially for DIYers with limited experience. However, with careful planning and by following key steps, even absolute beginners can successfully rough-in the water and drain lines for a new kitchen sink.

Whether you're replacing an old leaky sink or putting a sink in a completely new spot, these tips will set you up for success.

Getting Started - Planning Your Rough-In

The first step is all about preparation and planning. You'll want to determine exactly where the new sink will go, the proper height, what material pipes to use, and how you'll route them from the water supply lines to the drain connection.

Determining Sink Location

When choosing where to locate your kitchen sink, here are some key factors to consider:

• Traffic flow - Pick a spot that doesn't disrupt the workflow in the kitchen
• Accessibility - Allow enough clearance so the sink is easy to use
• Coordinate with cabinetry and electrical - Ensure no conflicts underneath

Generally you want to allow a space that's 36-48 inches wide for a single basin sink. If installing a double basin, allow 48-60 inches. This will leave room for the sink itself, faucet, backsplash, and some countertop on each side.

Taking Measurements

Once you've settled on the sink location, take precise measurements of the space to determine how much piping you'll need. Carefully measure from the water supply lines behind the wall to where your sink will go. Note any existing holes or openings in the floor or walls that you can route pipes through. Also be sure to mark where wall studs are located so you can secure pipes properly.

Choosing a Sink Height

Standard counter height in most kitchens is 36 inches. This allows the average person to comfortably use a sink installed at this height. However, you may want to install your sink a bit higher or lower based on the users in your home. For example, if you have small children or users in wheelchairs, adjust the height to meet their needs.

Picking Pipe Material

For water lines, you'll need to decide which type of pipe to use. Common options include:

• Copper - Very durable but rigid and tough for beginners to install
• PEX - Flexible tubing that's much easier for DIY beginners
• CPVC - Rigid like copper but with better heat resistance

Our recommendation would be PEX pipe. The flexibility makes routing pipes from point A to point B much simpler.

Installing Water Supply Lines

Once you know where your sink will go and have all the right materials, it's time to start routing pipes for water delivery. This involves running supply lines from the main water line to the sink location, installing shutoff valves, and connecting everything to the faucet.

Running Pipes to Sink Location

Plan your piping route in advance so you can neatly run pipes to where the sink will install. Be sure to:

• Secure pipes adequately - use pipe straps screwed to wall studs
• Make clean 90 degree bends using elbow fittings
• Leave some extra length to make faucet and valve connections later

Connecting Hot and Cold Supply Valves

Under the sink, you'll want to install shutoff valves on both hot and cold supply lines. This allows you to easily turn off water to the sink for repairs down the road. Position valves 8-12 inches apart under the sink bowl location. Use compression fittings for a watertight connection. Once assembled, turn valves to the open position and check for any leaks before moving forward.

Making Faucet Connections

Flexible supply lines have pre-attached fittings to connect to faucets. Simply push lines firmly onto the faucet tailpieces. The other end then connects to the supply valves with just hand-tightening. Turn on shutoff valves and confirm proper water flow and drainage.

Drain Line Installation

While water delivery is important, properly planning and routing the drain line is an equally crucial part of roughing in a kitchen sink.

Assembling the P-Trap

This iconic U-shaped pipe is the key to creating an effective sink drain. It prevents sewer gases from entering while allowing waste water to drain freely. Assemble from sections of tailpiece, slip joints, and elbows. Position the fully assembled P-trap so it aligns with the sink drain hole location.

Venting and Slope

In addition to the P-trap, plumbing code requires installing a vent. This helps water flow efficiently down the drain without "guzzling" from trapped air. You'll also need at least 1/4 inch per foot of slope downwards to leverage gravity for good drainage.

Routing Drain Pipes

Plan your drain line route from the sink tailpiece all the way to where it connects to main sewer/septic lines. You may need specialty Fernco fittings to transition between materials. Wherever possible, anchor the drain pipes well to prevent sagging.

Final Checks and Protection

Before closing up walls, plumbing rough-ins require some final checks and preparation for durability.

Pressure Testing

Use air or water to pressure test the full assembly of supply pipes and drain lines. Confirm no leaks are present and make any final fixes prior to covering up work.

Insulating Pipes

Wrap supply lines under the kitchen sink with foam pipe insulation. This reduces condensation buildup from temperature differences between hot and cold lines.

Firestopping

Seal openings made through firewalls with fire-rated caulk. This applies to protecting pipes passed between garage and home. Take this critical fire safety step before insulation and drywall.

Roughing in kitchen sink plumbing involves careful planning and step-by-step installation. While it may seem intimidating, breaking the project into stages makes it approachable even for absolute beginners.

Following this guide, you now know how to determine sink placement, select piping, securely route supply lines and drainage, plus conduct final safety checks. Taking precise measurements and using quality materials also prevents issues down the road.

The next step after rough-in will be actually installing your chosen sink basin and faucet. We recommend reviewing manufacturer instructions to ensure compatibility with your rough-in work before purchase. With the heavy lifting done though, making those final connections is quite straightforward.

As you button up walls and finish your kitchen, take pride knowing that quality plumbing rough-in work will serve the space well for years of meal prep and memories. Next time a leak or clog crops up, you'll also know just where to look and what to tweak.