Q: How do you keep shelves from sagging? The ones we're putting into our linen closet are 59 inches long and don't have any center support.
—Mary Jasper, Lakeville, Minn.
A: To prevent sagging, I generally keep a shelf's length to 36 inches or less. But if it has to be longer, and it isn't possible to put in intermediate supports, I'll build the shelf in a way that it comes out super stiff. Here's how to do it.