When we think of cleats, we often think of sports – soccer cleats, football cleats, running cleats. None of those examples have anything to do with nationality, just cleats on shoes.
But, what about French cleats? Do they come from France? Do they have anything to do with sports? That’s not likely, especially on a website about woodworking.
So, what are French cleats, and what do they have to do with wood?
What Is a French Cleat?
In woodworking, a French cleat is used to hang and secure something on a wall. It might be a painting, or a mirror, or a cabinet.
It is a piece of wood, solid or plywood, attached to a wall and with a 45 degree cut on the top edge angled inward; a second piece of wood, also with a 45-degree cut angled outward, is then fitted into the first piece so that the angle cuts form a solid and neat fit.
Later in this piece, you will find a helpful video that will show you clearly what we’ve just described.
Why Is It Called a French Cleat
Who knows? One theory comes from the term “Frenching,” which refers to cutting something into thin strips. “French” fries would be an example of this. Or, it simply could have originated with “French” influence on the world throughout history.
The name is less important than the how and why of French cleats, the materials used, the method of attachment, its strength, and how much weight a French cleat can accommodate. So, let’s get to it.
What Is The Best Size of Wood to Make a French Cleat?
Plywood is a good material choice for your French cleat. It’s cheaper than solid wood and will provide the strength you need for most anything you want to hang. Keep in mind that kitchen cabinets are hung simply with screws into studs, and those cabinets can support hundreds of pounds of weight without much of an issue.
However, be sure to choose a Grade A or a Grade B plywood. Lower Grades are more likely to contain knots and weak points, whereas these grades will be denser, have a better surface, can handle a heavier load, and be less likely to splinter or warp.
How Thick Does a French Cut Need To Be?
As for the thickness of the plywood to use, choose at least ½ inch, although a ¾ inch plywood will serve you better. This will give you a strong and secure hold that can handle great weights subject to the number of studs you attach the cleat to and the style lag screws you use.
The French Cleat Angle Cut
As mentioned above, the angle cut on French cleats should be 45 degrees, which forms a 90-degree connection, which means the full dimension of the piece of plywood you are using for the cleat. The cleat you attach to the wall, with the 45-degree cut angled in and down, should be slightly longer than the piece being hung in order to provide that extra measure of stability, strength, and balance.
Can You Use MDF For a French Cleat?
MDF, medium-density fiberboard, is engineered by breaking down pieces of hardwood and softwood into fibers. It is then mixed with wax and a resin binder and formed into boards using high temperature and pressure. It is dense and heavy and has many practical applications.
It has a strong and smooth surface, takes paint well, and is often used in furniture, cabinetry, and closet shelving for light loads. It is less expensive than plywood but is not as stiff and will tend to sag over time.
However, it is not a good choice for French cleats. Its density does not give it greater strength than plywood, and it is susceptible to changes in humidity and heat variation that can cause weakening over time.
How Strong is a French Cleat?
The short answer is very strong. When the wall cleat is adequately anchored in studs, rather than simply in drywall, a French cleat can support tremendous weights. Drywall anchors are not strong enough to support French cleats to hang a large mirror, for instance, or a painting with a heavy frame.
For proper French cleat strength, the wall cleat should be anchored in at least two wall studs using lag screws. Lag screws are exceedingly sturdy and tough fasteners used to connect woods that are carrying heavy loads.
A single lag screw in a wood stud can bear a weight of between 80 – 100 pounds; two screws can hold 160-200 pounds. The wall cleat should be wide enough to fit two lag screws and span a minimum of two studs.
That math should tell you how strong a French cleat can be and how much weight it can hold. You want to distribute the weight to be carried among as many studs as possible, so the greater the weight to be supported, the more studs you want to use to carry it.
A French cleat weight limit, then, will be determined in part by how many studs it is screwed to and how many screws are used to connect to those studs. The plywood grade and dimension will also determine its strength.
But, when optimal materials and stud counts are used, a French cleat is very strong. French cleat failure can be avoided when choosing the correct dimensions for your plywood, using suitable lag screws and attaching to the right number of studs.
A French Cleat Wall
Many woodworking shops will use French cleats to organize and store their power and hand tools for easy access and out-of-the-way storage. An entire wall will be built with multiple rows of linear wall cleats and individual shelves and boxes hung along those running cleats holding their tools.
We found a terrific video that shows how to build such a French cleat wall and thought you’d like to watch. It shows in detail how French cleats are built and puts into practice what we have recommended in this piece.
Whether you’re hanging tools, like the fellow in the video, or hanging a mirror, a painting, or shelves, French cleats are an excellent choice. They do not require any special skills, and you don’t need any special tools to create them.
If you don’t have a table saw, a chop saw will work just as well. A measuring tape, a stud finder, a power drill, some lag screws, a level, and safety goggles are all you need. It’s an easy project and can be built relatively quickly.