I know that knob and tube is addressed in code, but I was curious to know if you would take a job that was 2-wire with addressing the lack of a ground? The house has been vacant for 10yrs and I can't truly determine the integrity of the wires. I haven't talked with the inspector yet, but the owner says that they have and that the inspector says it is only a matter of wire integrity. How would you approach the situation?
Should I rewire?
- Thread starter Benton
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growler
Senior Member
- Location
- Atlanta,GA
I normally do a visual inspection first, service then attic and basement or crawl space. 10 years is a long time for a building to remain vacant so I look for vandalism and critter damage (rats, squirrels or any other varmints). Does the place look like bums have been living there or was it pretty well protected? If the light fixtures, switches and receptacles are still in place and there is no sign of damage then I hook up a generator to the service and turn it on and see if things are working properly.
To be honest I don't think I have ever found a house that's been empty for 10 years that didn't have some sort of damage.
Even if everything is in good order and in original condition the local authorities may want GFCI protection in kitchen and bath room and even smoke detectors and the ground for the service may need brought up to code. I have no idea what they will want in that area so you need to get with the local inspector.
You charge to do an inspection of the property and any repairs are a seperate issue.
I did a lot of them growing up in father's business. None since, but I would have no fear of the work. K and T can be generally good quality.
Change the service and run new romex to all the heavy loads and appliances. Don't leave a washer, fridge, or microwave on the old when you are done. Knob and tube is fine for what it was designed for in 1930 when the only loads were a few incandescent lamps and one or two small motors. Take the load off the K and T and leave it in place where it is covered in the walls for existing lights and a few convenience outlet loads. Check with the inspector first for an approved method of transitioning from romex to K and T in the basement at the point where it goes up in the wall. If they are insulating the walls or ceilings, imo, K and T is not rated for insulation contact and would be coming out. Remove it from where it is accessible and replace with romex.
I would GFI at the panel and not try to change devices or concealed splices. As soon as you commit to changing all the devices and open the boxes, you'll probably find the boxes are too small and everything is coming out. I would change devices individually when they fail. K and T with soldered splices can last forever and is good quality. Twist and tape splices are already in the process of failing.
GerryB
Senior Member
- Location
- woodbridge, ct. USA
Sounds like good advice from someone who has done it. I would just add that you can get new 2-prong devices to change existing and it is not difficult.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
I have been asked to do a job extending and adding circuits in a house, the original portion of which is circa 1930 but has been added to extensively at several times since then. The wiring in the core section is fabric insulated two wire cable (no ground of course), the individual conductors of which look a lot like the K&T that I have seen. The owner's home inspector called it K&T, but there are no support knobs or penetration tubes because of the outer sheath. The existing splices are in boxes but are soldered.
What am I working with here and should I treat it the same way I would K&T?
Any clarification you can give would be appreciated.
PS: Some circuits in the old portion (like the electric range) are MSC, and all of the exposed wiring at the main and sub panel are run in conduit or are NMSC, but I can't tell what is in most of the walls except by removing outlet covers and fixtures.
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