Unfinished basement electrical re-wiring, protecting cables on cinderblock, also corrosion concerns

Question

My basement has old electrical wiring, looks like it was a replacement for some even older knob and tube (which they largely left in place of course). While they did wire up lighting somewhat, though far from optimal, they did nearly no outlets. They also did no proper light switching, so it's a sea of pull chain lamp holders, excluding a couple thoughtlessly placed light switches that control just one lamp holder. There is one duplex receptacle and a dryer receptacle, that is it.

The basement walls are a mix of faced and unfaced concrete (possibly some cinder) blocks. They added a crawlspace, which was thankfully enclosed. The basement is not dry as it should be, so it has a running dehumidifier, and looks like a prior owner extended the house envelope into the basement. Like most everything done, that also was shoddy DIY.

I want to correct the entire basement electrical, get proper outlets for usage, the basement has a second room which I've been using for a workshop. As of now I'm only able to use my portable tools though, since only near the dryer is there that one badly overloaded duplex receptacle. There is also the main electrical panel, with a second small load center next to it, on the same wall as the clothes washer and dryer. The two panels, and the receptacles, are mounted on plywood. I'm assuming the plywood is just screwed directly to the wall.

I believe the DIY house envelope extension, and the dehumidifier, were attempts to control the moisture/corrosion problem in the basement. I do plan on doing that properly, sealing crawl space vents, replacing any badly corroded galvanized ductwork. My ceiling is just exposed joists (on 16), and at least they didn't break codes on stapling Romex.

What is the best practice way to run electrical lines from the exposed joist ceiling to place electrical receptacles and proper light switches on block walls? Always on plywood first? Anything under the plywood to deal with potential wood rot? How should the wall lines be protected? I'm having the whole thing re-wired, so what is the proper way to do it? Romex in something like a conduit? How would that be attached to the block wall?

Answer 1

Having lived in Dayton in the 80’s and having a basement, I had a similar experience 1 switch for a light over the washer dryer and 1 120v duplex and a single 240v for the dryer. I used Romex for the wiring with EMT down the walls to the boxes that were anchored to the walls with a strap close to the top and box. since I had the receptacles at 4’ this met code. I used tapcons or that type of concrete screw for the straps and boxes. I pulled the main panel loose from the masonry wall and anchored a 3/4” plywood behind the panel with screws holding panel to the plywood. I had planed to finish the basement so I had receptacles placed on the walls (at 6’ intervals not 12 as code allows) today unfinished basements require GFCI with the 2017 code (I haven’t checked the 2020 code) but Ohio has had a similar adoption of the code to my current state so the 17 code will probably be enforce until May and 2020 code enforcement in November. As far as wet damp location, other than bathrooms I have never been questioned using Romex inside a building envelope or in the living spaces. You can check with your local inspectors, I had no problems back when I rewired my entire cape cod as it was wired with white as the hot! Yikes ! And finished the basement. The inspector liked the panel mounted on the plywood and verified that I did not use wood plugs. Other than that I really don’t remember him checking anything other than polarity and ground. I did create 4 lighting zones , my man cave & bar area, the washer& furnace, the bathroom area and the stairway lights that also lit the area to the panel no more pull strings. When I added the internal walls I tapped the receptacle circuits for the new walls and added 3way switches at the entry to the 3 areas that were originally a single switch at the bottom of the stairs the stairwell was always 3 way I added the lights to the panel to that circuit. This is what I did back then GFCI was not required but today since it will be unfinished you will need GFCI protection by an outlet or breaker for the receptacles, I don’t know if Ohio has an exemption for dedicated washing machines like Oregon has but knowing how often GFCI protection fails on motor loads if you have the option to have a dedicated non GFCI I would recommend it.