The other day, a friend was talking about undertaking a project to replace all the old knob and tube wiring in his house, which resulted, roughly in the following exchange:
ME: “Knob and tube? I didn’t think your house was THAT old, when was it built?”
HIM: “1961”
ME: “Geez, I didn’t think they were still using it then. My house was built in 1955, and it’s Romex.”
HIM: “It must have been upgraded. They didn’t have Romex then.”
He’s conceded that Romex was around in 1955 (it was established as a trade name in 1922). I don’t have any reason to believe that my Romex is anything but the original wiring. It seems to be 2 wire Romex (ungrounded).
Everything I read suggests that knob and tube got phased out in the 40s and 50s. How common would US house construction using knob and tube have been in 1961? More specifically, in the SF Bay area.
It would have been extremely uncommon. I’ve never seen a house built past the 1930’s that had knob and tube wiring. My house was built in 1960 and has 2 wire Romex.
I agree, knob & tube in new construction in 1961 was someone hanging on to the old technology several years past almost everyone else.
I help my dad re-wire our house in about 1966 or 1967, and we used wire and components essentially just like those in use today, e.g. romex type cable, modern breakers and panels, etc. And it wasn’t like it was some new fangled stuff at the time, it was what everyone had been using for a while.
The house I own now was built in about 1947 and it had knob & tube originally. But it seems to me from the places I’ve worked on that even that was later than most people had changed over. So I would have also been surprised to see knob & tube in a 1961 house.
Is it possible that your friend was simply mistaken about the date of construction? (When was knob and tube wiring no longer permitted in new construction?)
Many communities retained old codes into the 1960s, but if your house was built before his, and used Romex, then it seems unlikely that that’s the case. K&T wasn’t completely eliminated until grounding became mandatory in the 1960s, and was still used in flood-prone areas of Louisiana until the 1970s.
I was wondering about that, but I did a quick check on his place with zillow.com, and they have it listed as 1961, so that’s likely what he was told when he bought the place.
Nametag - my place being built before his can’t be used to infer anything about the codes his place was built under. We’re in different municipalities and counties, several miles apart, so they were built under different codes. 1961 just seemed a trifle late under any code.
I wouldn’t trust Zillow or even the property appraisers office for the actual year built. My last house was listed as being built in 1977 but was actually built some time during the 60’s.
The house I am in now is listed as being built in 1955, but I severely doubt that as the style is older. Wood frame, old farmhouse type.
Significant improvements can alter the property appraisers data, then it is just listed as “effective build date.”
Oftentimes when the year of construction is uncertain, the Realtor or appraiser will check the date molded into the inside of the toilet. This only works if the toilet has not been replaced during the house’s lifetime.