How to Install Sliding Barn Doors

by Steve Smith; Updated September 26, 2017

Installing a sliding barn door requires the use of a trolley (a rail system that carries or moves the door from side to side) and several rollers that ride along this track. The installation will take the better part of a day, and requires mounting the trolley just over the barn door opening, then attaching the rollers to the barn door, and sliding them into place. You will need at least two people and maybe three or more to complete the job. Together, they need to be strong enough to lift and hold the barn doors for several minutes.

Items you will need

  • Barn door, including trolley, rollers, and mounting kit
  • Assistants
  • Drill and bits
  • Mounting bolts
  • Plumb bob
  • Scissors lift or sturdy ladder

How to Install Sliding Barn Doors

Step 1

Line up your rollers along the top edge of the barn door about one foot apart for the best results. With a pen or marker, mark the holes in the base of each roller on the door itself while it is in position. Drill the holes.

Step 2

Attach the rollers, using heavy-duty 2-inch wood screws or the bolts that come with the rollers (mounting hardware should be included with the doors). Use a dab of wood glue or adhesive when you install the rollers.

Step 3

Mark and drill holes for two more rollers on the bottom of the barn doors, and install them as described in step 2.

Step 4

Measure the entire height of the barn door, including both rollers, and write down the exact measurement. Now, apply this measurement to your barn door opening. If it is 10 feet 3 inches, measure 10 feet 3 inches from the very bottom of the barn door opening, and make dark marks, using a marker.

Step 5

Line up the middle of the trolley track with these marks over the barn door opening, and make larger marks on the mounting holes in the trolley tracks. There should be a mounting hole at least every two feet. If not, drill additional mounting holes in the track using a metal bit.

Step 6

Ask a helper to hold the trolley track in place on one side, then attach the track to the barn, using a drill or power driver. Use the hardware provided with the track, or 1/4" or 7/16" bolts that are long enough to go right through the barn walls. Bolt the tracks into place at each mounting hole in this manner.

Step 7

Lay the bottom track along the floor of the barn. Straighten it with a level, then test the alignment of the tracks, using a plumb bob (a large pointed metal weight on the end of a string). Hold the string of the plumb bob in the middle of trolley track, and let the weight dangle just above the floor. Position the bottom track so it is right under the plumb bob. (This ensures the two tracks are perfectly aligned.)

Step 8

Hoist the barn door up into a vertical position and lean it up against the barn, just beyond one end of the trolley track. Carefully, lift and slide the rollers one at a time both onto both the bottom track and top track. The barn door should just slide along the track until it's in position.

Step 9

Cap both ends of the trolley tracks by drilling a hole into the track (if one is not already in place) and driving a large 1/4" bolt into this hole. You can thread the bolt through a block of 1" x 1" wood to create a stronger stopper. Or, use the stopper included in your sliding door trolley.


  • Take time to align the trolley tracks, this is the most important step in installing a sliding barn door.

About the Author

Steve Smith has published articles on a wide range of topics including cars, travel, lifestyle, business, golf, weddings and careers. His articles, features and news stories have appeared in newspapers, consumer magazines and on various websites. Smith holds a Bachelor of Arts in English and journalism from University of New Hampshire Durham.