
I have a wood mirror that is 80" wide and 18" tall, and which weighs 38 lbs.I plan to mount it horizontally on heavy duty French cleats, which were provided by the seller. There are four cleats on the back of the mirror frame, arranged in "quadrants". Then I have four more cleats to mount on the wall, for the ones on the mirror to slide into. Each wall cleat is 20" long, so that it can be screwed into two adjacent studs. So that's a total of eight screws drilled into wall studs that will be supporting 38 lbs.What kind of screws do I need to use? I assume I need wood screws, but how do I figure out what size? The screw holes in the wall cleats are 3/16" in diameter...Specific questions:What determines the weight that a screw can hold -- the length or the cross sectional area?If it's length that matters, what length do I need for it to be safe?What kind of head should the screws have? The wood screws I've seen have a "cone shaped" head, which doesn't seem ideal, because I think I need a head that will sit flush against the French cleat.It's been suggested I should use lag screws. Does that sound right?Given the screw holes in the cleats are 3/16" in diameter, should I use screws in that size, or should I go a little smaller (maybe 5/32", which I think is a #8)?Thanks! via /r/DIY http://ift.tt/2fGGBml