Want to jazz up that mirror with a nice frame? Plenty of people do. Framing mirrors is a popular way to make mirrors stand out on a wall. But be careful. Framing a mirror can be challenging.
The difficulty begins with the way people approach mirrors, which is often different than the way they approach art. When framing art, people typically put the art in the frame, and then hang it on the wall. With mirrors, all too often, people put the mirror on the wall, and then they try to fit the frame over it.
Even when a mirror is hung after being framed the situation can be problematic if the footprint of the mirror on the wall is predetermined, as is sometimes the case when contractors are making the call. In such cases, the specified dimensions are the outside dimensions of the framed mirror. From the framer’s perspective this is challenging because the “frame size” is never considered to be the outside dimensions of the framed piece. The “frame size” is always considered to be the dimensions of the recess at the back of the frame that the contents are loaded into.
When measuring to fit a predetermined footprint, the framer must start with the footprint and then subtract the width of the frame times two, plus the allowance, which is another 1/8” on each dimension, to arrive at the size of the mirror. From a framer’s perspective, this is a very inside out way of approaching the issue. For more on this, see How to Determine Frame Size.
When attempting to frame a mirror that is already mounted to a wall, another problem becomes evident. The frame’s rabbet depth is not adjustable. All too often, the customer selects the frame for the way it looks and without regard to its rabbet depth. But if the mirror is 1/8” thick and the rabbet depth of the frame is 3/8”, then when the frame is placed over the mirror there will be a 2/8” gap between the inside of the recess and the mirror, enough to be noticeable.
One cannot help but point out that if the mirror were placed in the frame before it was hung on the wall, this would not be an issue, but if the mirror is already glued to the wall, and then the frame is fitted over it, the problem can only be solved by selecting a frame with a different rabbet depth.
As a general thing, most challenges with framing mirrors can be overcome by treating the mirror as if it was any other piece of art. Put the mirror in the frame first and then hang the framed mirror on the wall. Also, if you can avoid specifying an exact footprint for the framed mirror, you will find the process easier.