Bolts key in hanging heavy shelving

Q: I just put a deposit on some unique metal storage shelves at an architectural salvage business. This metal monstrosity used to hold auto parts. Without anything in the unit, it weighs well over 200 pounds. How do I hang it on the wall and make sure it will not come crashing down?

A: You’re so lucky to have an architectural salvage business near you. I had a similar business near me when I lived in Cincinnati. That’s where my wife and I bought a gorgeous solid walnut fireplace surround and mantle that we used in our new home. I get great pleasure from seeing old items recycled so they get a second or third life, rather than ending up in a landfill.

To secure your new metal storage shelves to the wall, I’d recommend using a French cleat.

A French cleat will have to be fabricated by a local welder. It consists of two pieces of metal. One piece is a strip that’s nearly as wide as your new shelves. It gets welded to the top rear edge of the shelves.

The second piece is bolted to the wall, and it has a slight outward bend toward the top of the strip. It needs to slant out only about ¼ inch. The metal strip on the back of the shelves slides down behind the slanted piece of metal on the wall. The two interlock, and it’s impossible for the shelves to slide down from the wall or tip out — as long as the metal strip on the wall is securely bolted to the wall studs.

In my opinion, the best way to bolt this metal strip to the wall is with through bolts. The easy way is to use lag bolts, which are just giant screws. The potential problem with lag bolts is they can lose considerable holding power if the pilot hole is too large and/or if the bolt is overtightened by an aggressive installer.

Using through bolts is more work, but they hold so much better. These bolts have nuts and washers on the end of the bolt that passes into the finished wall behind the metal storage shelves. A typical way to attach the wall strip of a French cleat is to pass the bolts through solid blocking that has been securely installed between the wall studs.

To do that, you have to have access to the back of the wall to tighten the nuts onto the bolts. This requires lots of planning as the drywall on the other side of the room can’t be finished until the rack is installed.

If you can’t do a French cleat, then you might be able to bolt the shelves to the wall through strong metal that’s part of the outer frame of the shelving unit. It’s hard for me to give you expert advice here because I can’t see your shelves.

You’ll have to decide what type of bolt you’re going to use with this method. Lag bolts can work. They just have to be installed with great care, and you need to make sure the bolt is passing directly through the center of a wall stud.