How to Find Joists for Laying Hardwood Floor

Written by glenda taylor Google
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Find Joists for Laying Hardwood Floor
(Jupiterimages/ Images)

When installing a hardwood floor, you’ll nail the wood floor planks into the floor joists for support. After you strip off the current carpeting or flooring, the joists will still be out of sight, covered by underlayment. Following a few techniques carpenters use, you can figure out where the floor joists are and use them to install your new hardwood floor.

Skill level:

Things you need

  • Hammer
  • Chalk line
  • Measuring tape
  • Nails

Show MoreHide


  1. 1

    Examine the underlayment. You may notice a nailing pattern that runs in rows. This is where the original builder connected the underlayment to the floor joists.

  2. 2

    Tap on the underlayment with a hammer. When you tap above a floor joist, you’ll hear a solid sound. When you tap over a space, the sound will be hollow. This is a handy technique when you can't see a nailing pattern.

  3. 3

    Go to the basement if it’s unfinished, and locate the joists from beneath. Drive in a long nail beside a joist until it extends into the room above. Note the direction the joists run. You’ll install the wood floor planks so they cross the direction of the joists at a right angle. Don’t step on the nail when you go back upstairs.

  4. 4

    Measure from one joist to locate the rest of the joists, using a measuring tape. Floor joists are typically spaced 16 inches apart, but in some older homes, they may be up to 24 inches apart.

  5. 5

    Pull up a floor register if the underlayment is painted, and there is no basement access. Look into the ductwork leading to the register, and determine which direction the joists run, since the ductwork installs between two joists. This will also tell you the general location of the joists on either side of the register and a little tapping with your hammer will pin down the location.

  6. 6

    Test the location of the joists by inserting a nail into the floor at that spot. If you nail only into the underlayment, the nail will resist for approximately 1/2 inch but then it will slip in easily. However, if you’ve located a joist, the nail will resist the entire way into the wood.

Tips and warnings

  • Pop a chalk line over every joist before you start laying the hardwood flooring planks. When you install the flooring, the chalk lines will be your guide, letting you know exactly where to drive the nails.
  • Remove any nails you use as guides before laying the hardwood flooring.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.