Many people line the bottoms of their ovens with aluminum foil, since this heat-resistant material can keep food and other materials off the oven surface. However, lining an oven with aluminum foil may be detrimental in the long run.
Lining an oven with aluminum foil can cause heat damage or affect oven performance. According to Premier Electric & Gas Ranges, a sheet of foil can be used in electric ovens, as long as it does not touch the element. Reynolds Products, a major producer of aluminum foil, recommends against using foil to line ovens.
Aluminum foil can also hurt air circulation in an oven, especially when used to line entire racks. Covering an oven rack completely with foil reduces circulation and causes cooking problems.
While lining the oven itself does not work well, you can still use foil to catch drips. Simply place a loose sheet of foil, edges turned up, on the rack directly under cooking food. Remove the foil after use.