The identification of earthen house floors or living surfaces during archaeological field investigations can be hampered by the scale of excavation, variable fieldworker experiences, and any number of site formation processes. Furthermore, although time- and context-sensitive sampling protocols (e.g., those required of macrobotanical and microartifact data collection) rely on in-the-moment identifications of floors, strong empirical evidence for the presence of house floors often comes well after the field season has concluded. Pocket penetrometers—inexpensive instruments that measure the compaction strength of soil—can lend empirical support to decisions about sampling procedures during onsite investigations. In this study, we present findings from the analysis of 4,463 penetrometer readings recorded during the excavation of residential and non-residential architecture at Welqámex, a Stó:lō-Coast Salish settlement in southwestern British Columbia. We show how pocket penetrometer data reveal quantifiable differences in the compaction of floors and other cultural deposits. We argue that compaction measurements can provide an additional line of data (ratio scale) to affirm or challenge onsite interpretations of stratigraphy based on other tactile and observational data, particularly as such interpretations pertain to surfaces expected to have been exposed to recurrent foot traffic