Subfloor Preparation Before Installing Bamboo Flooring

Subfloor in kitchen

You’ve looked at all the advantages of bamboo flooring, and you’ve decided it’s the right solution for you. Subfloor preparation before you begin is a critical part of the installation process. You want your sub-floor to be flat, clean of any dirt and debris, and properly prepared for your bamboo flooring.

Step 1: Set Your Temperature and Humidity Level

Before you start installing your bamboo flooring, you’ll want to allow it to acclimate to the normal temperature and humidity of the room. Before starting your subfloor preparation, bring the bamboo flooring into the room and ensure that the room is at its normal year-round temperature and humidity. This will ensure that the flooring is properly acclimated before you start the installation process. It will ensure you don’t have to wait several days for the bamboo planks to acclimate after preparing your sub-floor. Ideally, your bamboo flooring should acclimate for at least 72 hours before installation. Also, bamboo flooring can be installed in dry or humid climates, so in those environments, we recommend at least 10 days of acclimation.

Step 2: Make Sure the Sub-floor Stays Dry

When you install bamboo flooring, you must have a sub-floor that will stay dry year-round. If you have a wood sub-floor, make sure that the moisture content does not exceed 12%. A concrete sub-floor requires less than three pounds of moisture emission per square foot, and you must use a 3-in-1 underlayment under a floating floor. If you’re wondering, “Do I need an underlayment for bamboo flooring?” For a concrete sub-floor, yes, you do. You’ll need an adhesive with a moisture barrier if you’re gluing the floor down. If you’re concerned that your sub-floor emits a lot of moisture, perform a calcium chloride test to determine how much, and if you’re gluing down the floor, make 100% sure that the adhesive you’re using has an upper moisture limit that can handle the moisture level of the sub-floor.

Gluing Down Bamboo Flooring – Tips & Tricks from Ambient Bamboo Floors on Vimeo.


Step 3: Secure Your Sub-floor

When you install your bamboo flooring, subfloor preparation requires that the sub-floor is secure, tight, and free of squeaks. Your sub-floor must be properly installed to prevent future issues! Now is the time to fully examine every part of your sub-floor to make sure that it’s secure. This includes:

  • Checking nail or screw placement on the sub-floor to ensure they’re tight, and add new long screws where squeaky (You should have a nail or screw placed every 8″ along the joists to avoid problems with squeaking.)
  • Replacing any boards that have rotted or broken down over time

Step 4: Make Your Sub-floor Level

You don’t want your subfloor to have any buckling or raised spots because they can cause installation and daily use problems. Therefore, your subfloor must be flat and level.

Sand first. Start by sanding down any raised spots across the sub-floor. Make sure that it is flat to 3/16 of an inch within a 10-foot radius. When you’re done, you must clean away the dust since dust beneath your bamboo flooring installation can cause future problems.

Fill in dips or other spots that are too low. Use a self-leveling compound for your low places, and smooth it into place along with low spots with a putty knife. The compound should have the approximate texture of pancake batter when you put it in place.

Allow the compound to dry. Use the time recommended by the manufacturer’s instructions to be sure the compound is completely dry. Test it for dryness before proceeding; if it’s not dry, wait before moving on to the next step.

Sand rough spots in the compound. Make sure it remains level by checking with a contractor level before proceeding to the next step.

Clean up any dust creating by your sanding. Make sure that you haven’t left a mess!

home under construction with sub flooring in kitchen exposed

Concrete Sub-floor Concerns

If your sub-floor is made of concrete instead of wood, it must be properly prepared for your bamboo flooring (Installing Bamboo Flooring over Concrete). First, make sure that it has been cured for at least 60 days before beginning your installation. This will ensure that the concrete is arid and settled before you install the flooring.

Step One: Sand and Level

Use a sander for sanding the concrete floor flat and level. A contractor’s level will allow you to determine whether the flooring is level across the room easily.

Step Two: Double Check Moisture

There are several methods for checking the moisture contained within the concrete sub-floor. The easiest way, however, is a calcium chloride test. You can also tape down a two-foot by two-foot square of plastic over your concrete floor and leave it for 48 hours. If there’s moisture beaded on the inside of the plastic, continue to Step Three below.

Step Three: Install a Moisture Barrier If Needed

If you’re struggling with the moisture levels in your concrete, you’ll need to use a floating floor over a 3-in-1 underlayment or glue the floor down using an approved urethane wood floor adhesive with a vapor/sound barrier. This will prevent mold and mildew growth, and it will keep the bamboo planks from being ruined by the sub-floor moisture.

Proper attention to your sub-floor is the best way to keep your bamboo flooring looking its best once installed. By taking the time to check your sub-floor carefully rather than rushing the process, you’ll get to enjoy bamboo floors that look their best throughout the lifetime of your floors. You’ve put plenty of time and effort into deciding what type of floors will work best for you, so take that effort a little further by carefully preparing the sub-floor before installation.