A leak overhead is read as worry seeping in — small problems or feelings getting past your defences. Dream books take it as a nudge to repair what has been letting the rain in.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.