I'm tearing down an old house and ran into something curious .... I know that's what killed the cat Anyway, on the oldest part of the house the subfloor is oak with 3-4 layers of linoleum, then 4x4 sheets of plywood. In 1 room each plywood sheet has 2 holes cut in it, approximately 2"x5" filled with the cut out plywood [attached with 2 nails] That plywood was covered with linoleum and then waffle padding and carpet.

Anyone know why the plywood keys would have been used?

 

My first guess would be that the plywood was repurposed, with the holes being for whatever purpose they served the first time around, and the patches they used to fill in happen to be the same type. Like maybe the plywood had been used for wainscot, and the holes were for receptacles? Sound plausible?

 

My guess is the 4x4 sheets original purpose was different than sub-flooring and the person doing the flooring picked them up for a bargain. He cut a matching plug and nailed it in.

 

The holes seem a little long for receptacles but the plywood being used is a plausible idea. I wondered why none of the plywood was bigger than 4x4 ..... but didn't complain as it made it easier to pull up

Old timey construction is interesting. The original portion of the house looks like it was built in stages [close to 200 yrs ago] The floor joists consist of hand hewn logs. Where the oak flooring is, the logs are approximately 3' on center but in the kitchen where they used pine on the floor they are set on 2' centers [approximately] The pine is 1.25" thick, the oak in the middle room is 1" thick and the end room is 1.25" oak. The width varies from 6" to 10" Most of the walls were 12" wide pine or poplar tongue and groove.

 

One of my greatest joys of remodeling is trying to figure out what was going through the mind of the contractor decades ago when they installed whatever I am renovating. Its kind of like a little walk into history with each remodel.

Now the current project I am working on, renovating a condo in a ski resort, is another ball of wax. The previous homeowner was not a contractor, but an engineer and everything is wrong. There is a loft which I had to totally reframe the support structure as it was unsafe. Every screw that this guy used was stripped and near impossible to back out, stair tread were installed with carpenters glue, and they had the great idea to paint the walls orange. But slowly we are correcting these errors, but it never seems to amaze me what a novice is likely to do.

Good Luck on your project Marksr, keep your head up and enjoy the ride.

 

The thing I grin at every once in a while when tearing into certain projects is that there have been and continue to be a lot of people with a lot of initiative who enter into projects not necessarily thinking through the entire process or simply not aware.

 

It was! I was down there this afternoon trying to get it ready to burn on saturday and noticed on several of the pieces of plywood - NABISCO was embossed. Not sure what it was previously used for [maybe a crate] but that diffidently proves the plywood wasn't bought new to install over the oak subfloor.

 

I'm getting into this way late, but my guess is the key holes were used for dog-bones or something similar, which clamp the edges together after gluing:

 

My original thought was they were there to prevent the plywood from slipping for some unknown reason. These boards were only in one room and no adhesive was used. Since a company name was embossed in the plywood I'm now convinced those pieces were originally used for something else.