In 1967, the US Department of Defense, Office of Civil Defense published a 28-page pamphlet on how to harden your home's basement to help survive against radiation and fallout from a nuclear blast.
Included is a chapter on "improvised" shelters - for those unlucky souls who hadn't completed their own personal bomb shelter:
If a workbench is not available, you can improvise a somewhat larger shelter area by using furniture, doors, dressers, or other materials.
Remove doors from their hinges and place them over supports in the corner of your basement having the best protection. The supports for the table can be chests of drawers or anything that can take a heavy load. Use two or three doors over each support for this shelter to provide sufficient strength to carry the heavy loads placed on them.
Place bricks, concrete blocks, earth- or sand-filled drawers, books, a collapsible swimming pool filled with water, etc., over the doors to provide an overhead shield. Use anything with weight that can be moved. The heavier the material, the more the protection.