When to Use Rebar?

by Ann
(Hoover, AL)

Hi Sue,
When is a panel so large that rebar must be used to stablilize it? And is there a difference for leaded and copper foil panels?
Thanks,
Ann

Hi Ann,

A panel larger than 2ft x 3ft should have rebar. But even that depends on where it will be installed. You must take into consideration how much vibration from slammed doors, wind, etc
it will get. There are so many variations, it's impossible to cover them all.

If there are hinge joints in the panel, you might want to use rebar on a panel as small as 1 ft x 3 ft. Also, you should always use copper restrip in both leaded or foiled panels with hinge joints, no matter what the size is, whether or not you use rebar.

We use copper restrip in most panels we make regardless of hinge joints. It is surprising how much restrip firms up a panel. Copper restrip is always run horizontal from one side to the other, making sure the ends go into the edging material (lead or zinc). There are times when we will run some restrip vertically as well as horizontally. Again it must go from top to bottom, and obviously it will be cut as it meets the horizontal strips, restarting on the other side of those strips. There are also times when we only use copper restrip without the addition of rebars.

A good rule of thumb for the distance between rebars is a rebar every 2 feet unless it's in a door. On a panel going in a door, 1 1/2 ft. would be advisable. Doors, whether they are external or internal, including cupboard doors, get a lot of slamming. Slamming causes the panel to move in a way that will eventually cause it to bow and then, farther down the road, the glass might start falling out. Properly rebaring a panel will prevent this from happening.

I hope this helps you. As I said before, there are so many variables it's difficult to cover all of them without writing a book on the subject.