Green’s Dictionary of Slang

cheap or inferior quality material, which is used to build houses.

1962		M. Reynolds Little Boxes (1964) (song) And they’re all made out of ticky tacky, And they all look just the same .
1973		Newsweek 30 July 71: Will [...] Watchung Pharmaceutical get those 250 unspoiled acres [...] to produce more poppable pills and sprinkle company ticky-tacky over the landscape?