Large mirrors can be a great addition to a master bedroom or an entrance hallway. The bigger the better. But mirrors can be incredibly heavy and without proper installation, they can tear screws and wall anchors out of any wall board, fall, and create an expensive and hazardous mess. You can find the tools to do the job right, even with the heaviest mirror.
Find a stud in the wall
Finding a wall stud is a vital first step for hanging your large mirror. The wooden stud will be a sturdier spot to anchor your supporting hardware than wall board such as Sheetrock. Find wall studs by tapping a hammer against the wall board and listening for a spot that doesn't sound hollow. You could also buy a stud finder, a handyman's tool available in a variety of price ranges at your hardware store. If you can't find a stud in the area you want to hang your large mirror, you will probably have to consider using toggle or molly bolts to support the weight of the mirror against the wall, as outlined in the next sections.
The right anchors
Once you know where you want to hang your mirror, drill holes where you will put the hanging hardware for the mirror. A large, heavy mirror can rip most screws and even many anchors right out of wall board. An anchor is a plastic or metal sleeve inserted into pilot holes through which a screw is attached. As the screw is inserted, the anchor expands on the opposite side of the wall board, creating a sturdy support on which to hang something.
Make sure you get the right anchors for the screws based on the weight of the mirror. Again, if you can't find a stud, toggle or molly bolts are the best option. Nylon toggle bolts will hold up to 34 Kilogram in half-inch wall board. Molly bolts will hold even more. Install them by sliding them into a pilot hole in the wall board. Once in the wall board, wings expand on the other side, spreading the weight of the mirror over more surface area. To be safe, install bolts rated for more weight than your mirror weighs.
Spread out the surface area
Much like the physics associated with the toggle and molly bolts, increasing the number of bolts can distribute the weight over more of the wall. Be careful not to put too many hooks or bolts too close together; that could weaken the structural integrity of the wall board and rip out a big chunk of the wall. Be sure to place each support at least 4 inches from the next.
Mirror Hanging Kit
For all mirrors, especially the larger, heavy ones, a mirror hanging kit is essential to purchase and attach to the back of the mirror's frame itself. These kits have a variety of hardware in them, usually consisting of metal mirror clips and holders and small nails or screws to affix them into the back of the frame. A long strand of metal hanging wire can be run the length of the back of the mirror, as is done on large picture frames. This will help distribute the weight of the mirror across a wider number of hooks.