If you live in or near an area known to be susceptible to tornadoes and hurricanes you really should have your own storm shelter. If you haven’t got one already there’s plenty of help available on how to build a storm shelter. So, whether you’re an experienced DIY enthusiast looking for a new project or just need to save some money by doing it yourself; building a storm shelter could literally save your life.
Regulations and Standards
The whole reason for having a storm shelter is to protect you and your family from the lethal effects of severe storms. Subsequently you need to know what the regulations and required standards for how to build a storm shelter yourself are. For this and other information on protecting yourself from severe storm weather, residents of the USA are advised to refer to the National Storm Shelter Association and the Federal Emergency Management Agency.
By far the commonest type of storm shelter is an underground one. Whilst this gives the best protection from projectiles thrown around by a hurricane or tornado, they are more difficult to construct and require a ventilation system. There is a type of storm shelter known as a ‘Berm shelter’, which whilst being essentially underground its roof is above the ground level.
Berm Storm Shelters
You’ll need to be confident working with concrete to build a Berm shelter. Having excavated a pit for the body of the shelter to sit in, you first need to create a concrete base/floor. Onto the base construct a dome shaped wooden frame and cover it on the outside with plywood. This forms the mould over which you pour more concrete to create the walls and roof for the shelter; using layers of wire-mesh to reinforce the concrete.
On the front of the shelter have a steel plated door that opens outward, needless to say the door needs a steel frame. You can finish the inside of the timber frame with a cladding and put in a bench or some chairs. When finished you can clad the outside of the shelter with masonry to make it blend in with the surroundings and allow you to install a waterproof membrane.
Below-ground Storm Shelters
A below ground storm shelter can be outside of the main building, in the cellar of a house or even under one of the floors in the house like its garage. The first essential point with an underground shelter is excavating the pit in which it will be placed. You need to think in terms of a space larger than the dimensions of the storm shelter itself, as you need to allow for an access stairway down into it. This usually means that to build a DIY storm shelter it’s best to do it outside of the main building.
Having excavated the pit and entrance the first thing to do is to create a concrete base/floor. You can have several options for the walls of the underground storm shelter that you’re building. You will need to construct a sturdy wooden frame inside the pit first and install a waterproof membrane of the outer wall of the frame. Into the frame you could pour concrete, again reinforced with wire mesh or you could screw metal sheets to the frame and then bolt them into the floor.
Of course, if you’re experienced enough, a better steel solution would be to have one continuous wall of welded steel around the frame. Whichever method you decide to use, study the regulations on ventilating underground shelters and allow for any necessary apertures. An outward opening steel door in a steel frame should again be fitted. Finally, the roof of the underground shelter needs to be a single slab of reinforced concrete, capable of resisting forces of at least 200lb/square foot.