Hello fellow DIYers!
I'm looking at hanging a large self made entertainment unit. It's similar to a Kallax. 16mm boards with open back. I am trying to work out if the approach is strong enough. Alternative is to use bench legs which would be easier but not get floating look. I was going to attach 65 X 19mm X 2.4m Tas oak pieces to wall on 6 studs, then attach same to back of unit with screws on top and side into chipboard. Width of unit is 3.3m so quite heavy to manoeuvre.
Just worried the French cleat will break with force, or clear piece breaks away from main unit from chipboard?
Drawing attached. Will it be fine?
Is it possible to attach a single length of timber to the unit and then screw it directly into the studs? That would leave you with fewer points of potential failure.
A concern I have with your proposed method is that french cleats can fail if they hold something quite deep. They are great for carrying heavy objects close to the wall, though. Say, for instance, you went with this plan, and someone came and sat on the front edge of the entertainment unit. I do not doubt that the mating sections of the french cleat could fail or pop off each other.
I'm in two minds, but potentially creating a variation of the French cleat, as I've pictured below, could provide a greater surface area of contact. You could even screw the two mating sections together to fix them permanently. I feel my design below is inferior strength-wise, but it is less likely to fail from the sloped mating surfaces disengaging.
Let me mention @ProjectPete to get his expert thoughts.
@jasejw I agree with the risks @MitchellMc has cited in his response. The main issue is the angle of the French cleat which is why @MitchellMc suggested profile would decrease the chance of slippage caused by frontal load on the unit.
From your drawing it appears you intend to have screws fixed through the top of the unit to secure the French cleat to the unit itself. If this is the case (ie. You're OK with visible top-fixed screws, you could just install a standard (read: strong) ledger on the wall and screw the unit into the ledger through the top of the unit.
If you haven't already fixed the hoop ply top, you could do the screw fixing as mentioned above first, then cover them with the hoop ply top.
Thanks Pete. I'll probably opt for steel legs and just screw through the melamine into studs at ends. Will update. Cheers.
Keep us updated @jasejw, and please reach out if you need further assistance.