pegged mortise and tenon joinery discovered in two pre-fire erie steet wood framed cottages

on the "deconstructing chicago" front, my interest is in demystifying the incredibly complicated methods and materials used during the span of time from 1840-1880, when evolving technologies, as well as supply and demand for material, continually wavered from one building season to the next.

the case study explored in this post involves two nearly identical wood-framed workers cottages constructed and/or moved to a single lot along erie street on the near west side of chicago.

unfortunately, any and all identifiable characteristics on the exterior (e.g., molding, clapboard, etc.), which greatly assist in dating the cottages, were removed or covered over through time. otherwise visible characteristics of age include the overall profile, and the fact that both cottages were raised on a brick basement (for the purpose of creating additional space to rent out to boarders and/or as a consequence of remaining above grade when streets and sidewalks were raised as more and more of the city became dialed into the sewer system).

from what i've discovered thus far, both in field data and periodicals, the two cottages were likely constructed during the early to mid-1860's as single store wood-framed houses with no indoor plumbing. a privy vault or pit, with a circular pine wood floor located between the two houses suggests human waste and everyday refuse was deposited in this well-constructed vault.

note: pine wood vault floor undergoing restoration.

during the late 1860's or possibly early to mid-1870's (researching ongoing), the single story cottages were raised onto brick basements with slightly arched top windows likely outfitted with 2-over-2 sashes.

further research is needed to determine whether the cottages were built on the site or moved from a nearby lot, and to find whether one house is older than the other. the rear cottage did retain some of the original multi-part door casings, but that was likely installed during the 1870's. the front house had been thoroughly "modernized."

when i looked behind the walls to examine the physical characteristics of the sheathing, studs, lath, types of nails used, and even a brief glimpse at the sill plates in both houses, there wasn't much to determine if one was older than the other. during the course of demolition, even when i had greater access to the building materials and the methodologies were fully exposed, i failed to arrive at any definitive conclusions on whether one house pre-dated the other. i  began to strongly consider that they were built at the same time, with the same materials and methods. this was corroborated by the the size of the notched sill plates, the arrangement of the joists, the use of faceted wood pegs for reinforcing the mortise and tenon joinery, saw markings, and so forth.

the two houses are the latest of nearly a dozen demolished over the past year, along a two block stretch on erie street, where wood pegs and the use of post and beam (versus balloon frame construction) are repeatedly found. this suggests the same builder or contractor constructed these houses during 1860's chicago, with very little variation in the materials and methods used in their erection.

remarkably, the yellow pine wood residential sill plate segment - pictured above and below - retains the original tapered and faceted wood peg, despite the fact that the beam containing the interlock tenon was haphazardly pulled away during demolition.

the excavation phase, long after the houses have been demolished, also reveal virtually identical privy pits, positioned in relation to where the house or houses were built on the lots. often the pits were dipped, so they have yielded very few artifacts. in the few cases where intact bottles were found, they nearly all date to the mid-1860's.