Floating "Entertainment" shelf question

[dinkjs]

We are moving in a couple weeks back to the Indianapolis area and I am going to build a floating two shelf "entertainment" unit.  Basically it is going to hold just my Apple TV...Going with a minimalist look.  The depth will be a standard 12 inches with a french cleat holding the shelf up.  I wouldn't think it would need any type of special anchoring other then drilling into the studs on the cleat side onto the wall.  I just need clarification on this.

 

[nclemmons]

It could be sufficient depending on the design.  Do you have a drawing / photo? 

12" is a lot of overhang with downward force that could pull the shelf off the french cleat.  A drawing would help to understand the forces at work.

I'm always concerned about 'minimalist' designs that end up with someone putting something heavier on them, or leaning against a shelf with their arm holding a drink, or whatever!

neil

 

[greg mann]

Neil is right to be concerned. Normally, a 45 degree angle is used on a French Cleat. If the shelf is only 4 or 5 inches thick it would peel right off at that angle unless it has some bracketry pushing against the wall underneath of at least 12 inches. That more or less defeats the purpose of a floating shelf. I would not feel comfortable with a FC design with any angle over 20 degrees if the shelf is 12 inches deep and less than 5 inches thick, and that is just off the top of my head. I would certainly draw it out on paper to look at the force vectors that would be trying to tear it off the wall.

 

[tjbnwi]

These cherry floating shelves look taller than they are due to the incorporated light valance. The shelves are torsion boxes 5" tall plus 1.25" for the light valance. They are hung on french cleats with 45º back cuts. I made the cleats tight to the interior of the box, chamfering the bottom edge of the wall cleat. I believe I went 2" on the top cleat that is mounted to the box. I had to "roll" the shelves in place. The shelves are in no way attached to the wine bottle rack on the left side of the photo, they are only pushed against it.

I think the load is greater than an Apple TV box.

Tom

 

[dinkjs]

These cherry floating shelves look taller than they are due to the incorporated light valance. The shelves are torsion boxes 5" tall plus 1.25" for the light valance. They are hung on french cleats with 45º back cuts. I made the cleats tight to the interior of the box, chamfering the bottom edge of the wall cleat. I believe I went 2" on the top cleat that is mounted to the box. I had to "roll" the shelves in place. The shelves are in no way attached to the wine bottle rack on the left side of the photo, they are only pushed against it.

I think the load is greater than an Apple TV box.

Tom

That is exactly what i am visioning....except a cubby hole for the apple tv box

 

[rmwarren]

Neil is right to be concerned. Normally, a 45 degree angle is used on a French Cleat. If the shelf is only 4 or 5 inches thick it would peel right off at that angle unless it has some bracketry pushing against the wall underneath of at least 12 inches. That more or less defeats the purpose of a floating shelf. I would not feel comfortable with a FC design with any angle over 20 degrees if the shelf is 12 inches deep and less than 5 inches thick, and that is just off the top of my head. I would certainly draw it out on paper to look at the force vectors that would be trying to tear it off the wall.

Greg, would you have the same concern if the angled FC was replaced with cleats with opposing rabbets? I am thinking of something like this:

[attachthumb=#]

I am getting close to lining my little shop with FC's and will want to most load-bearing I can get. Any input would be appreciated.

RMW

 

[tjbnwi]

Okay Greg, explain why. What does the height of the shelf have to do with anything, when it comes to the french cleat??? I would never do a cleat without a 45º angle.

If you are using a 1x (3/4") board to make the cleat, no matter the height of the shelf the purchase is 1.0605". The angled intersection also allows you to "tap" the shelf "tight" to the wall. The lower rail will also contact the wall.

In the rabbet style, I see 4 major problems, first you the rabbet follows the long grain, we all know that the long grain is the weakest direction of the grain. The board can split along this line. The french cleat also follows the long grain, but at the bottom it is the full width of the board. Second, if you're using a 1x (3/4") the purchase is only 3/8", much less than a french cleat. Third unless the walls are perfect and the lap joint is dead on, how do you "snug" the shelf to the wall? Forth, why have the face grain die into edge grain? Again unless everything is perfect you could end up with an undesirable intersection. No matter what you choose to do, you need the lower rail to contact the wall in its entire length.

There are metal cleats available, they work like a french cleat, but look like the rabbet cleat. 

dinkjs, build your shelves and hang them off a french cleat with a 45º angle cut. Make the cleat as tight as you can, yet able to install to the back opening of the shelf.  The opening for your AppleTV box will have no affect on the strength of the shelf, as long as you follow the 1/3, 1/3, 1/3 rule.

Tom

 

[tjbnwi]

Here is Rocklers offering in steal cleats;

http://www.rockler.com/product.cfm?page=347

Also look at Monarch Z clips.

Tom

 

[tjbnwi]

This bar mirror is hung off a wooden french cleat. Stop blocks were placed on the wall at the bottom, inside the unit so you have to pull the bottom out and lift to remove it from the wall. It's been on the wall since the weekend before the Bears lost to the Colts in the Super Bowl. (Seeing as you're moving to Indy)
https://picasaweb.google.com/tbadernwi/BarMirror#

Tom

 

[greg mann]

This bar mirror is hung off a wooden french cleat. Stop blocks were placed on the wall at the bottom, inside the unit so you have to pull the bottom out and lift to remove it from the wall. It's been on the wall since the weekend before the Bears lost to the Colts in the Super Bowl. (Seeing as you're moving to Indy)
https://picasaweb.google.com/tbadernwi/BarMirror#

Tom

I see no problem with your mirror application even without stop blocks as the height of the whole unit is so great. Your Cherry shelves look to be about 4 inches high and 4 inches deep, give or take. Again I see no issue but if your shelf was, say, 12 inches deep and only four inches high I would be concerned with it peeling off the wall. I am sure we could do a layout to determine at what ratio we cross a threshold where it is no longer safe to use a 45 degree cleat but I thought it useful to point out there is one. I do like the idea of stop blocks and had not thought of suggesting them. They would at least mitigate or more likely completely eliminate my concern because the back of the shelf could not rise up out of the cleat no matter how much weight was put on the front edge of the shelf. If I had thought of them I would have made that suggestion as it preserves the original design intent and makes the shelf very secure.

BTW, Great work on both projects, Tom.

 

[tjbnwi]

Greg,

Thanks for the compliment.

The shelves are 10.5" deep, 5" tall.

Tom