A Covered Bridge

Most of the images of covered bridges are nostalgic, sort-of Currier and Ives, type of representations. But in reality, covered bridges were and are built to solve a problem with heavy snowfall and freezing temperatures. Because bridges are over water, the moisture from the river or stream tends to build up on the bridges as ice. The covered bridges were built to prevent the accumulation of ice and snow on the colder surface of the bridges. The reason for this this that there is no subsurface under the bridge and so it is cooling down from both the top and bottom. If you drive around where there are not covered bridges you will commonly see signs that say watch for ice on bridge.