French Cleat advice

[sucramuk]

Hi Again oh learned ones.

I seek advice again.

As some will have seen from my other posts I am trying to build a hanging curved floating shelf / hanger.

I have now worked on an idea of french cleat to secure to wall. Ideally i saw some slimline aluminum ones but alas not available here is SA (something to consider later on).

So have fallen back on the a normal french cleat, constructed from 18mm birch ply.

I want the cleat to be as wide as possible so would machine to follow the contour of the bend, then to give it added security so that the cleat does not knocked apart when stuff being hung on it a screw from the fixed backing into the wall cleat.

The weight that is going to be hung of it will be around 10 -12 kg.

Would the attached work? I hope so as hopefully this is the last step of planning. I think!!

 

[Mr T]

How much weight will be going on the shelves? French cleats work best on taller pieces such as cabinets. As your shelf is only 85mm high any weight on it may have the effect of levering off the wall cleat. It would have to be very well secured if the shelf is taking weight.

Chris

 

[RobinBHM]

I cant see a French cleat working.

The problem you will have with trying to achieve a fixing just at the rear is the tendency for the shelf to sag. Projecting out 300mm at only 85mm high means a lot of pressure on the wall joint.

The best solution is a cantilever construction, which would mean drill deep into the wall and resin fixing threaded rod that stick out to support the shelf.

 

[ED65]

For what it's worth weights greatly in excess of 10-12kg have been successfully hung from French cleats made of plywood. But the levering forces once you move out from the wall must be considered, and probably the only way to be sure would be to build it and test it.

Instead of a conventional French cleat you might prefer the added peace of mind of this system:

 

[AJB Temple]

Remember that the actual weight of the shelf plus objects on it is not the relevant consideration. The shelf is acting as a lever and the effective weight will depend on the weight loading and where it acts on the fulcrum point. The effective weight (force acting on the fulcrum point) can give a much higher loading than the static weight. 12kg right up against the cleat (which is in effect the fulcrum point) is much less of a load than 12kg at the edge of the shelf furthest away from the cleat. I can give you the formula if you want and fancy a bit of maths. But otherwise, over engineer it!

 

[AndyT]

I think there is a clue in the picture caption - the OP wants this to hang a bike on. I guess how far out it is from the wall will depend on the style of handlebars. A quick image search shows me that plenty of people want such things to look stylish but I'd advise going for strength rather than appearance.