A basement bulkhead is a structure that allows access to a basement from the outside of the house. The structure is usually made of concrete or stone, and it includes a stairway that leads to the ground level. The basement bulkhead is often covered with a metal structure that includes one or two doors that swing open or closed. This prevents water from entering the bulkhead itself, potentially leading to water damage or flooding inside the home. The doors can be locked as well to prevent unwanted visitors from entering the home. The metal basement bulkhead doors are installed at the top of the stairs, while another door may be installed at the bottom of the stairs to improve insulation.
If the basement itself does not have a door installed to separate the basement space from the basement bulkhead stairway, one can be installed, or a homeowner may choose to simply insulate the bulkhead itself. This is particularly useful if the area is a finished basement used as a common living area. Insulation or an inner door will help keep warm air from escaping the basement and cool air entering it through the bulkhead doors at the top of the stairway. Unfinished basements do not require insulation or an interior door, though installing one may help make the heating of the home more efficient, especially if heating components are stored in the basement.
A drain system can also be installed at the bottom of a basement bulkhead to further protect the basement from rain damage. This drainage system is usually comprised of a wide cut into the concrete foundation and a metal grate covering it for safety. The opening allows water to drain away from the foundation rather than settling into it or flooding the basement. The drainage system may feature pipes that drain the water far away from the foundation, or it may simply dump the water into the ground beneath the foundation. Such a system is useful for preventing water damage caused by small to moderate amounts of water, but it may not be effective at diverting heavier flows of water.
Older styles of basement bulkhead structures were made from stone, and the bulkhead doors were often wood. The wood was especially susceptible to rot and decay, and the more modern metal doors remedy this, since they are more resistant to corrosion and rot. Bulkhead doors may be made from galvanized steel, which is resistant to water damage, or other metals that are coated with some sort of waterproofing to protect from water damage.