You can easily attach a back to a work stool or a bar stool. Many kits are available online for specific stools; however, you can design your own with a few basic materials. The materials you choose will depend on if you're looking for style or just support, but almost everything you need should be available at your closest hardware store. Be sure to measure the stool carefully before shopping to ensure you get the right materials.
Measure your stool. The depth of the seat is particularly important, as the screws must be at least 1/4 inch shorter than the seat. Otherwise, you risk going through the bottom of the seat. You should also determine the desired height of your stool back.
Choose a backrest and L pipes. Look online for stool back kits, but if you don't find any you like, consider using other materials. Portable seats for bleachers, the back of a computer chair or even an ergonomic support could serve as a back. The L pipes should be shorter than the diameter of the stool seat and tall enough to support the back.
Drill four holes in each pipe -- two at the base and two where the seat will be. Make sure to space them out at least an inch. Put the holes near the top of the seat to make a more stable backrest.
Screw the L pipes into the stool, then screw the backrest onto the pipes. Check for security and stability. You can add screws or a crossbeam if your backrest is shaky.
- Thinkstock/Comstock/Getty Images