Hollow-wall anchors are great for hanging pictures, framed mirrors and bulletin boards on drywall. But these fasteners aren't strong enough to support extremely heavy loads. And they often work loose when used to attach fixtures that are always being jostled and tugged at, such as towel racks, toilet paper holders, grab bars and curtain rods.
The simplest way to safely attach any type of fixture—no matter how big or how heavy—is to drive the mounting screws directly into wall studs. Unfortunately, that's not always possible. You can usually find one stud to screw into, but seldom is a second stud exactly where you need it. For example, in the installation shown here, we mounted two towel bars one above the other about 6 in. from a wall corner. It's very rare that a stud would be positioned so close to a corner; the nearest one is usually 16 or 24 in. away.
Plus, we didn't want the stud locations to dictate where the towel bars would go. So instead of worrying about where the studs were, we cut open the wall and installed a horizontal 1x4 solid backing that allowed us to securely fasten the mounting brackets exactly where we wanted them.
Here's how to install 1x4 backing for mounting two towel bars. The process is the same for attaching other types of wall-mounted fixtures, with one notable exception: When installing a safety grab bar, replace the 1x4 with a 2x4 and secure it with countersunk lag screws.