"Here are some ideas for making your inner refuge. One. Make a ‘lean-to’ with sloping doors or strong boards rested against an inner wall. Prevent them from slipping by fixing a length of wood along the floor. Build further protection of bags or boxes of earth or sand, or books, or even clothing, on the slope of your refuge, and anchor these also against slipping. Partly close [...]"
January 1, 1970
https://en.wikiquote.org/wiki/Threads_(1984_film)