There is nothing as amazing as a floating shelf that has been installed using a French cleat, a system that allows units and shelves to float without the joinery being visible. However, many people will have tales of French cleats failing and causing entire shelves to suddenly fail and fall.
To avoid failures of your French cleats, ensure that the backing brace has been secured onto studs or solid bricks. The joinery is made out of a solid piece that has been cut to have the best fit instead of gluing two pieces together with the right angle to join onto the cleat.
Many people fail to realize how structurally unsound they are making their pieces when they take shortcuts or are not using the right cutting tools. We recommend understanding how a French cleat works and knowing what types of French cleats can install shelves, sinks, or wall units.
How Much Weight Can A French Cleat Hold?
Depending on the construction of the French cleat, it may only be capable of holding around 20 pounds, or it may be able to hold well over 75 pounds without flexing. The angle that the French cleat has and its construction will heavily influence the total weight it can carry.
We always recommend thinking about how the French cleat will be used before simply creating it and building the cabinet with it. If the cabinet or shelf is only a few inches long and has to hold no more than a few picture frames, then the French cleat can be of the simplest design.
However, if it is going to be a complete design that needs to hold several tools, pictures, mirrors and have a revolving amount of stuff on it, then a strong design is necessary. The steeper the angle of a French cleat, the better it will transfer the weight and pressure onto the bolts that hold it.
Further, making the French cleat larger or thicker will help secure the cleat and the shelf in place without sacrificing the aesthetics of the entire shelf. Most artisans creating French cleats that are used with wall units will have a solid cleat that runs the entire length of the unit.
How To Make A Strong French Cleat?
To make a strong French cleat, you will need three things, a steep angle, solid wood pieces, and a strong internal skeleton. The French cleat should not be trying to compensate for the entire length of the shelf or cabinet; instead, it should be spread equally across the entire length of the cleat.
Many DIYers that create their first French cleats assume that they can make a regular shelf and simply use the cleat to hold their shelves onto the wall. However, this is not true, and the internal skeleton of the cabinet or shelf is just as important as the French cleat itself will be.
If there is no easy way for weight and other pressures to be transferred onto the French cleat, then the entire structure may start to fail or bend over time. This is the most often part that you will see fail, as the French cleat will stay intact, but the shelf will crumble from constant flexing and bowing.
What Is The Best Spacing For French Cleats?
If you are building a longer shelf or wall unit, you should leave no more than 5 inches between each French cleat. If you have more than this, the weight might not be distributed evenly, and certain parts of the French cleats will start to fail long before some of the other parts will.
You can see the effect of improper spacing of French cleats when parts of the shelf or wall unit are suddenly starting to flex more than others. This means that the cleats in that part of the wall have started to fail, and the other cleats have started to take damage from the over-flexing.
Many times, when a shelf does fail, you can see that only one or two of the French cleats have completely broken or snapped. Most of the other French cleats are ripped entirely from either the wall or the shelf itself, causing the structure to fail to be of improper spacing rather than anything else.
What Are The Types Of French Cleats?
Generally speaking, there are no exact types of French cleats. Every artisan will have their way of making the cleats and installing them when finishing the project. However, we have found ways of defining the four main types that you could learn to use from other experienced artisans.
These are light-, medium, and heavy-duty cleats and the much more complicated double French cleat that can be used. Categorizing cleats in this way means that you can determine when to use a simple cleat for a shelf that only holds a picture or a shelf that needs to support a complete sound system.
Light-Duty French Cleat
These are the cleats that are usually spaced out, and the cleat itself is made out of plywood that has been shaped into the right angle. Further, when creating a light-duty French cleat, you only need to place one or two throughout the shelf no more than 3 to 4 inches in length.
If your shelf or wall unit is wider than 10 inches, sticks out from the wall more than 7 inches, or is made out of heavier wood, you cannot use the light-duty French cleat. The unit or shelf you are creating would be too heavy for the bolts in the French cleat to keep everything stable.
Medium-Duty French Cleat
These are the most commonly used French cleats that we have seen. They are usually one long French cleat with the internal framework of the shelf or unit attached to it. Cut at least with a 45-degree angle; this French cleat will allow you to build the shelf out of most woods and still be strong enough to support more.
We always recommend learning how to make French cleats such as these as they will be most likely to help your shelves stay stable for longer. However, there are limitations, and these French cleats can fail if the shelf or unit is too wide and sticks out too far from the wall itself.
Heavy-Duty French Cleat
This French cleat forms the entire back brace of the shelf or unit you are building and will be made out of solid hardwood. These cleats are significantly more robust and will allow you to easily and comfortably rest several pounds of materials, TVs, speakers, and more without a problem.
These cleats can be extremely tough to design as you need to space them perfectly on both the shelf and the wall you are mounting them to. Further, the cleat needs a proper internal structure to work; just leaving the cleat to support the entire weight can cause cracks to form that weaken the bolts.
Double French Cleats
Usually used on TV units that are being wall-mounted, a double French cleat has the cleats at both the top and the bottom of the unit. This French cleat style allows for a complete skeleton that creates a strong and rigid structure throughout the entire TV unit that provides everything you may need.
This type of French cleat is not often used because of the inherent complexity of using several cleats that are not just further away from each other but also above and below. Most artisans learn how to use these French cleats when building floating kitchen shelves.
How Strong Is Each Type Of French Cleats?
Now that we know what the four most general French cleats are, we need to determine how strong they will be when built properly. We always recommend that you keep in mind that your French cleats may weaken as they age and that more does not always mean better.
Many artisans have used heavy-duty French cleats and then not properly connected the shelf or unit’s internal structure. This causes them to have a unit or shelf that is weak to pressure from above, but unstable when pushed from the side, which is the opposite of what a French cleat should be.
The Strength Of Light-Duty French Cleats
Generally speaking, we recommend using light-duty French cleats when creating smaller shelves that won’t have to carry more than 30 pounds. These French cleats are perfect for nested units between other shelves or are meant for decoration only.
If used properly, a light-duty French cleat can easily help transform a bare wall into something filled with life and character. These cleats are best for small photo frames or other items that won’t weigh much and will rarely be moved as long as you live in the house.
The Strength Of Medium-Duty French Cleats
These are the most common French cleats and will be used in TV units meant to float and bookshelves. A medium-duty French cleat that has been installed properly can help the shelf or unit easily support up to 50-pounds of weight, with nested units handling over 200-pounds.
It is important to know that French cleats are used to create floating shelves, sometimes in nooks or crannies with three walls. This means that the structure of the shelf or unit is allowed to transfer all of the weight to the surrounding walls. This means the breakpoint changes to the breaking point of the wood.
The Strength Of Heavy-Duty French Cleats
We mostly see these types of French cleats used in workshops or homes that have been exquisitely designed to look modern. A heavy-duty French cleat may not be built out of wood at all. They can be made out of a metal or steel framework that has been hidden inside the wood of a shelf.
This means that if it is built correctly, a heavy-duty solid French cleat can easily support several hundred pounds of weight on top. The only weak points are where everything is connected and the walls, which is why you may find them in designer cabinets.
The Strength Of Double French Cleats
A double French cleat is hard to judge as many people use a combination of French cleat types, with some using full-length cleats at the top of a unit and only a few inches at the bottom. This means that the double French cleat can easily handle up to 100 pounds or even more if built properly.
The strength of this type of French cleat is how it allows the internal structures of a wall unit or shelf to spread the weight throughout the cleats. With proper triangulation and joinery, these cleats work to help create stronger connections that allow people to put their entire entertainment units on top.
Why Do French Cleats Fail?
French cleats usually fail because they have either been installed incorrectly, using the wrong wood, or the cleat joinery is made out of multiple parts. This means that the cleat cannot transfer weight and pressure to the wall where it can be safely dispersed.
The most common issue we see is that people cut a strip of wood to the right angle then glue it to another piece to complete the cleat structure. However, this creates the weakest French cleat joiners as the wood fails over time, and the entire shelf may drop or fail instantly.
French cleats are never recommended to new artisans specifically because so many things can go wrong with them. If used properly, they create beautiful floating shelves that can easily hold up everything in your house, or they can be a failure waiting to happen that will break your precious memories.
A proper French cleat is easy to reinforce and will mean that your shelves or wall unit looks like part of the wall behind them. These cleats are easy to understand in theory but can be extremely difficult to implement when you have several other things to stress about.
Always remember, sometimes the best is to keep everything as simple as possible.