The concept of a metallic dome over the earth isn't a biblical teaching. It comes from the theology and "science" (more aptly referred to as philosophy, considering the time) of the dark ages. This is determined by examining the scriptures and finding the concept to be totally absent, then discovering an anomaly in the translation of Genesis 1:6, where the word expanse is translated from the Hebrew raqia, which means "spreading out." Since the root word from which raqia comes is raqa, which is sometimes used in a sense of "beating out" some confusion has been caused by the Greek Septuagint translation of raqia as stereoma, which means "firm and solid structure" concluding when the Latin Vulgate used the term firmamentum because, at that time it was thought that there was a metallic dome surrounding the earth with sluice holes from which rain fell.
The International Standard Bible Encyclopedia states: "But this assumption is in reality based more upon the ideas prevalent in Europe during the Dark Ages than upon any actual statements in the O T." - Edited by J. Orr, 1960, Vol. I, p. 314. For example, at Job 36:27-28 the water cycle is described without any reference to the Dark Ages understanding of sluice holes.