What is "Water Popping" a Hardwood Floor?

Water popping a hardwood floor is a technique used to richen a stain color that is applied to a raw hardwood floor during refinishing. During the sanding process, the reduction in grit sequence of the sand paper, that produces a smooth finish, naturally closes the grain of the wood. By saying closes the grain, I mean that the courser the sandpaper, the wider the grain fibers become in the sanded floor. To produce a smooth mirror like finish on a job site finished floor, you have to begin the sanding process with a course (low) grit paper to flatten and clean the floor, then progressively climd to higher (finer) grits to smooth the floor. As you climb to finer grits, the tighter the grain fibers become, in essence, making the wood denser and less penetrable. By water popping, you re-open the closed grain fibers of the floor allowing an applied stain to “soak” deeper into the grain of the floor.

Now that we know the purpose of water popping, let’s discuss the most common application method of water popping.

It is imperative that the water applied during water popping flow absolutely evenly across the entirety of the floor to be stained. In almost every circumstance, I use a “T” bar to water pop our floors. Should you fail to apply the water evenly; the floor will show blotchy areas under the stain from heavier or lighter areas of water penetration. Unfortunately, the only effective method of correcting uneven staining is to re-sand. If you are a DIYer, this will be a ton of extra work and additional cost associated with equipment rental, paper purchase, etc. If you are a flooring contractor, well, it’s gonna cost ya!

Water popping a floor with a “T” bar is relatively easy, assuming you have experience with applying water based finishes. It is basically the same process, except you are using straight, non-contaminated water. Many contractors and DIYers alike will use water straight out of the tap. Under most circumstances, this does not present a problem; however, occasionally utility companies add a little too much chlorine to their monthly or bi-annual treatments which can produce issue with cross contamination in some flooring projects. Our company always uses sterile water for all of our water popping applications. In other words, it is better to be safe than sorry! Use a standard watering can, that you water plants with, and pour a 2” line of water down on the floor (with the direction of the flooring grain). Pull your “T” bar in a snow plow position wall to wall, continuing to pour the 2” line of water as needed. Coat (or wet) the entire floor with the non-contaminated water and let stand for 2-4 hours to ensure complete drying.

Once the floor is dry, you will notice that the raw floor has a slightly “gritty” feel to it. Don’t panic! This is the desired outcome of water popping. The “gritty” feel of the floor is the grain re-opening. Inspect the entire floor to make sure that there are not areas that are either rougher, or smoother than the rest, as this is evidence of uneven water popping. Assuming you are satisfied with the results of the water popping, you may now begin to apply your desired stain color.

As in most instances, I recommend that home owners or DIYers not attempt to water pop and stain a floor, as there is a lot of room for error! If you are hiring a contractor to perform this type of hardwood floor project, I would also recommend quizzing them on their expertise and experience with water popping a floor. Just as there is a big misconception that sanding a hardwood floor is, “just putting some sand paper on a wood floor and scratching it up,” there is a lot of technique and ability that goes into water popping rather than just, “smearing some water across the floor.”. Remember, you get what you pay for!