hammer beam vs lath

hammer beam

noun
  • A member of a kind of roof truss (a hammer-beam truss), so framed as not to have a tiebeam at the top of the wall. Each principal has two hammer beams, which occupy the situation, and to some extent serve the purpose, of a tiebeam. 

lath

noun
  • A thin, narrow strip, fastened to the rafters, studs, or floor beams of a building, for the purpose of supporting a covering of tiles, plastering, etc. 

  • Microscopic, needle-like crystals, usually of plagioclase feldspar, in a glassy groundmass 

verb
  • to cover or line with laths 

How often have the words hammer beam and lath occurred in a corpus of books? (source: Google Ngram Viewer )