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Can I Install Bathroom Vanity Plumbing Through the Floor?

While most bathroom vanities have plumbing that runs through a wall installing plumbing through the floor instead carries its own advantages. In certain situations, plumbing through the floor is the only option available.

Depending on your situation, routing your vanity’s plumbing through the flooring can be an easy job or a costly venture. Therefore, it’s vital to know when plumbing through the floor will suit you best, and when going through the wall would be a better choice.

This article will aid you in making this decision. We will compare floor and wall plumbing. We will also include special considerations, necessary tools, and installation tips. Without further ado, let’s begin.

bathroom vanity plumbing through floor

The Pros and Cons of Installing Bathroom Vanity Plumbing Through the Floor


  • You save your walls from damage, cut-outs, and possible water damage by plumbing through your floor

  • Plumbing through the floor is easier to install if your home lacks concrete flooring

  • Floor plumbing is easier to hide inside your vanity

  • Sink drains run best when going straight down through floor plumbing

  • Plumbing through the floor can save wall space used for other plumbing or electrical lines in small bathrooms


  • Many pre-existing vanities will already be routed through a wall

  • Plumbing through a floor can be more difficult if you have a concrete foundation

  • Floor Joists can become an issue when plumbing through the flooring

  • Waterlines running through a floor can be more difficult to access

  • Plumbing through the floor can cost more time and money in some situations

Bathroom Sink Plumbing Through Floor vs. Wall

Installing a Bathroom Sink Plumbing Through The Floor

Installing your vanity’s plumbing through the floor is not as common as going through a wall, but sometimes plumbing through the floor can be a requirement. If structural joists lie behind your vanity’s wall, an inspector will likely have you go through the subflooring.

Access to your piping is an important consideration when doing an install. For example, if you have a basement or crawlspace, piping routed into your floor is usually easy to access. In addition, easy access to your pipes can save you from trouble in the future when the time comes to repair or replace these pipes.

When it comes to the installation process itself, plumbing through a floor is not much different than plumbing through a wall. Floor water lines need to be raised, which adds a little extra work. The main issue with floor plumbing is dealing with floor joists and concrete flooring, which can add a decent amount of additional time and financial cost to the project.

Installing a Bathroom Sink Plumbing Through A Wall

Most contractors consider routing a bathroom sink plumbing through a wall an easier task, which is why it has become a more common practice. But just because it is easier to do does not always make wall plumbing the best choice in every situation.

Access to your pipes is an important issue. If you are building a home from the ground up, your piping will be exposed. But if you are remodeling or replacing old pipes, you will have to cut out a large section of your wall to gain access to these pipes. Unfortunately, this is the only way to access pipes inside your wall, and it can become costly to cut out your wall each time you want to repair or replace them.

Wall plumbing is usually more strictly scrutinized by code inspectors as you must be mindful of electrical, structural joists, and certain slopes in your plumbing are required. But besides these special considerations, in most cases, plumbing through walls is easier and less expensive than plumbing through the floor.

Things to Consider When Installing a Vanity With Floor Plumbing

Tools You Will Need

  • A wrench (plumbers or adjustable)
  • A drill with many different bits and hole saws
  • Reciprocating saw
  • Pipes
  • Pipe fittings
  • Clamps
  • A level
  • Utility knife
  • Bucket
  • Safety equipment (eye protection, long sleeves, pants)

Installation Tips

  • Before doing any work with pipes, make sure you turn off your water supply.

  • Remove all doors, drawers, and other items from your vanity to make it easier to move and install.

  • Double-check the measurements on your vanity to make sure it will fit in your bathroom.

  • Keep the floor dry and clear of mats, trash, or other debris to avoid possible slipping hazards.

  • Cover your tub and toilet with a cloth tarp to prevent scratches as you move your vanity.

  • Taking extreme care when moving a vanity with a mirror to avoid shattering or damaging the glass.

  • Using exact measurements from the vanity itself, mark the floor where you will install the vanity and look for any discrepancies or issues.

  • When cutting pipes to length, it is always best to follow the old adage of measure twice cut once.

Kyle Tucker

Kyle from Kyle Tucker Plumbing is a certified plumber with over 20 years of professional experience installing plumbing fixtures such as bathtubs, sinks, and toilets, as well as installing gas lines and water pipes, performing bathroom repairs, and more.

Kyle knows how to deal with every plumbing issue that modern homeowners encounter, and he shares his lifelong experience with readers in an engaging and easy-to-digest way.

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