How much would it costs to replace knob and tube wiring?

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cheesepep
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How much would it costs to replace knob and tube wiring?

Post by cheesepep » Sat Oct 24, 2015 9:32 am

Maybe will put in an offer on a 1925 Spanish style house in SoCal (LA suburbs), about 1300 square feet with the knob and tube wiring.

There is no drywall, maybe just plaster?

Can someone give me a ROUGH estimate of how much it will cost (inclusive of plaster repair)?

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F150HD
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Re: How much would it costs to replace knob and tube wiring?

Post by F150HD » Sat Oct 24, 2015 9:48 am

cheesepep wrote:Maybe will put in an offer on a 1925 Spanish style house in SoCal (LA suburbs), about 1300 square feet with the knob and tube wiring.

There is no drywall, maybe just plaster?

Can someone give me a ROUGH estimate of how much it will cost (inclusive of plaster repair)?
Sounds like the entire house/garage would need to be rewired (?) did you call any local electricians for quotes on rewiring an entire house? It won't be cheap. Also, w/ city code I'm guessing if they start fixing "this" code may require them to fix "that" etc. Snowball effect?

I have plaster in my 1910 home, makes fixing things interesting....

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CABob
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Re: How much would it costs to replace knob and tube wiring?

Post by CABob » Sat Oct 24, 2015 9:52 am

There have been prior threads about knob and tube wiring. I don't recall if any dealt with costs but it might be worth a forum search by putting "knob and tube" in the upper right search box.
Bob

dbr
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Re: How much would it costs to replace knob and tube wiring?

Post by dbr » Sat Oct 24, 2015 9:55 am

The best answer would be to get some bids from contractors that might actually do the work. Understood that you don't own the house yet.

It might be worth asking here: http://ths.gardenweb.com/forums/wiring/

There could be substantial costs for interior renovation and repair of plaster. Would the project include other renovations that might justify hiring a general contractor for remodeling?

Valuethinker
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Re: How much would it costs to replace knob and tube wiring?

Post by Valuethinker » Sat Oct 24, 2015 9:56 am

cheesepep wrote:Maybe will put in an offer on a 1925 Spanish style house in SoCal (LA suburbs), about 1300 square feet with the knob and tube wiring.

There is no drywall, maybe just plaster?

Can someone give me a ROUGH estimate of how much it will cost (inclusive of plaster repair)?
Those houses are a gem, so good luck!

I think you need to call around 2-3 contractors and see what they say.

cheesepep
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Re: How much would it costs to replace knob and tube wiring?

Post by cheesepep » Sat Oct 24, 2015 10:00 am

From this link, it is about $20K without plaster repair.

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Slick8503
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Re: How much would it costs to replace knob and tube wiring?

Post by Slick8503 » Sat Oct 24, 2015 12:43 pm

A possible cheaper option may be due demo the plaster, have the wiring changed, and then go back with drywall. Something to keep in mind however, is that many older homes have rough sawn lumber, and the walls aren't true. This means the studs will have to be planed or shimmed in order for the drywall to turn out well. For plaster this does not matter because it can be evened out, as it is not solid going on.

z0r
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Re: How much would it costs to replace knob and tube wiring?

Post by z0r » Sat Oct 24, 2015 12:59 pm

I did this work myself on my own house. It matters greatly whether you have an open space above or below each floor you're re-wiring (in my case I had a good crawl space and also a spacious attic). The open space lets you run new wire in the clear and then drill down or up through the walls and fish to the existing boxes (this is an art in itself). I had to do some demo anyway, only maybe 3/4 could be fished this way. But in my case the demo was as easy as widening the box opening to the point that fishing was possible, not a whole wire track.

So, access will hugely affect the quotes you get. Mine was maybe a $10k job, if I had to guess (but I never got quotes).

A more important consideration is, why do you want to redo the wiring? Knob and tube is safe to continue using as long as it's in good condition. Some insurance companies will skip you but I have USAA and they didn't even blink. You can upgrade single circuits as needed for appliances and use the knob and tube for lights and outlets (properly accounting for missing ground). I did my swap because while the knob and tube itself was in good condition, the accumulated "upgrades" over the years to add boxes and fixtures were very poorly done, with, for example, speaker wire extensions to the knob and tube using wire nuts hidden in walls, in order to add a light switch.

z0r
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Re: How much would it costs to replace knob and tube wiring?

Post by z0r » Sat Oct 24, 2015 1:17 pm

forgot to add, I already had a modern electrical panel with 200A service. If you have a fuse box or similar, or limited current service, fixing that can add greatly to the cost. So my house (hypothetical $10k) probably represents the lowest possible cost/ best situation for a knob and tube swap.

Mingus
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Re: How much would it costs to replace knob and tube wiring?

Post by Mingus » Sat Oct 24, 2015 1:23 pm

cheesepep wrote:Maybe will put in an offer on a 1925 Spanish style house in SoCal (LA suburbs), about 1300 square feet with the knob and tube wiring.

There is no drywall, maybe just plaster?

Can someone give me a ROUGH estimate of how much it will cost (inclusive of plaster repair)?
A lot.

A good electrician can wire with minimal damage to the plaster by fishing the wires through the walls rather than opening them up. Depending on the size of the plaster damage, it's fairly easy to repair especially if it is a smooth finish. But being Spanish style, I imagine there is some sort of a textured finish to it that would take some practice to replicate.

Mingus
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Re: How much would it costs to replace knob and tube wiring?

Post by Mingus » Sat Oct 24, 2015 1:36 pm

Slick8503 wrote:A possible cheaper option may be due demo the plaster, have the wiring changed, and then go back with drywall.
I'd only consider that in the kitchen and the bathrooms as part of a complete remodel. And, I'd only demo as little plaster as possible.

A level 3 drywall job in Southern California is would be really expensive. Assuming the existing plaster is in good shape, a drywall job to replicate it would be vastly expensive.

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