As part of the renovations in my front room we will be fitting a floating solid oak mantel/beam above the fireplace (mantel dimensions approx 1520 x 150 x 150mm). The beam has been seasoned for 3-5 years.
I want the fixing to be hidden - so in terms of mounting I'd played around with a few ideas such as creating tenons that could be fitted to the wall to fit into mortices in the back of the beam locked in place by a peg driven up from the underside of the mantel...or a french cleat fitted to the wall and a corresponding recess routed into the back of the beam, I'd lock the cleat with a few screws driven again from the underside. In the end (and as they're not expensive) I've ordered 4 of these as they're probably the quickest solution (with a bit of construction adhesive on the back of the beam to keep it on the rods) http://www.hafele.co.uk/shop/p/concealed-shelf-supports/concealed-shelf-support-for-installation-into-woodwork-or-masonry-walls/11616/5956 (they're rated for 20kgs/44lbs each and the mantel should weigh ~30kg according to the supplier).
However it occurred to me that this may not be the best/fastest/easiest way of doing this so I thought I'd ask what you would do?