collar beam vs lath

collar beam

noun
  • A horizontal piece of timber connecting and tying together two opposite rafters. 

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 collar beam and lath occurred in a corpus of books? (source: Google Ngram Viewer )