Floating Shelves — Hidden Cleats, Exact Fit
A floating shelf is really a hollow box that slides over a wall-mounted cleat. If the internal cavity is off by even 1/16", the shelf either binds or sags off the cleat.
Typical parts
- Top and bottom — outer length × depth
- Front edge — length × height (mitered or butt-joined to caps)
- End caps — 2, depth × height
- Wall cleat — 2x4 or 3/4" ply, ripped to fit inside the cavity
Why measured thickness matters here
The internal cavity height is (outer height − top thickness − bottom thickness). Using nominal 3/4" instead of measured 0.708" changes the cavity by nearly 3/32" — enough to either bind on the cleat or leave a visible drop below it.
Related
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