old knob and tube job!!!

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Charlie Bob

Charlie Bob

Senior Member
Location
West Tennessee
I've been asked to inspect and attic where the wiring is knob and tube. Coons and squirrels got up there and chewed on the insulation , some wires are expoed, some are even cut off. The splices seem to be alright. But i can tell they've added circuits thru the years and the splices (between old NM , with cloth insulation , and k&T) are pitifull. House built in 1800's , plastered walls, about 12' tall, polarized ungrounded receptacles. It's goona required some serius work to rewire. The lady almost cried and told no cutting walls period.!!! I maybe able to rewire from the crawl space, but who knows what we'll run into. Tying K&T with new romex out of question, cause nothing will be grounded. Question is or are:

1-How would you all handle this one.?
2-You all like my crawl space idea?
3-Are you all glad is me and not you??? :smile:
 
electricalperson

electricalperson

Senior Member
Location
massachusetts
Charlie Bob said:
I've been asked to inspect and attic where the wiring is knob and tube. Coons and squirrels got up there and chewed on the insulation , some wires are expoed, some are even cut off. The splices seem to be alright. But i can tell they've added circuits thru the years and the splices (between old NM , with cloth insulation , and k&T) are pitifull. House built in 1800's , plastered walls, about 12' tall, polarized ungrounded receptacles. It's goona required some serius work to rewire. The lady almost cried and told no cutting walls period.!!! I maybe able to rewire from the crawl space, but who knows what we'll run into. Tying K&T with new romex out of question, cause nothing will be grounded. Question is or are:

1-How would you all handle this one.?
2-You all like my crawl space idea?
3-Are you all glad is me and not you??? :smile:
Click to expand...

i had to rewire old houses without cutting holes too. it takes a very long time to do it. but you never really know whats behind the walls there could be tons of blocking or it can be clear and easy to fish. crawl spaces work good too. cut holes where they cant be seen like closets
 
Buck Parrish

Buck Parrish

Senior Member
Location
NC & IN
I would never guarantee that I will not have to cut holes.
I will say "I'll keep them to as few as possible" But some times you have to cut a hole.
 
cadpoint

cadpoint

Senior Member
Location
Durham, NC
things you'll need

things you'll need

I'd check with the AHJ before you start anything, to find out the total cause and effect of getting involved upfront so everyones on the same page! IMO

A pencil and paper to map thier circuits.

Install GFCI's for all circuits at the home run!

optional:

Considered going down the bashboards? Most time they have the 6" - 8" size, (just a thought/ get a price from your carpenter)

Ridgid See Snake to look for block'n & a 3/8" bit or larger to creat hole to the eye. the snake comes with a 6' length but U can buy an additional 6'.

A stud finder for location cross blocking (and it might be diagional)

Beleive or not some older house's are open and don't have a header nailer (cap) at ceiling line.

The Electrican Handbook has examples of reworking knob and tub. I beleive theres also some diagrams that have been posted here!

Good Luck, post some Pic's!
 
S

SEO

Senior Member
Location
Michigan
Tell her that you'll keep the holes to a minimum and if she doesn't like that let her choose what type of surface raceway she wants instead. (Wiremold)?
 
S

sethas

Member
Location
Los Banos, CA.
ive rewired quite a few knob and tube places. you might suggest using wiremold boxs attached to the baseboard. mount it directly to the baseboard, and fish it in through the crawl space.

for light switches it gets a tricky. because of the aformentioned blocking, i try to install an outlet below the switch. makes it easy to fish up to the switch. from there you can either use a flex bit to get to the attic for the light switch leg, or just run it back down to the crawl space. i have installed a couple of chases in the back of closets for the lighting switch legs. they are usually hidden by clothing, so most homeowners dont mind.

remember you have to let them choose between spending a lot of money, no wiremold, and no chases, vs saving some money for an asthetic trade off.
 
Charlie Bob

Charlie Bob

Senior Member
Location
West Tennessee
thanks you all

thanks you all

The baseboard is about 6" or 8". I didnt measure it ,but the receptacles are in it!!!! which sucks. I'm going back tomorrow and study on it a little bit more. I'll keep you all posted.
 
al hildenbrand

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Breathing new life into old dwellings has been my bread and butter.

There's been some good tricks listed already.

What's the type of construction? Is it "stick built" or masonry?
 
e57

e57

Senior Member
Location
San Francisco, CA
Got a lot of time in old Ed's and Vic's.....

I can not speak for methods everywhere, or the condition of the job in question - but I often do what I can to save holes in certain hard to replace finishes by keeping some of the K&T. It's the finishes and charm that is making that lady nearly faint - she just sees a butcher coming in.

Me - I'm selective and up front - this an that gotta go, this can stay - I recommend that.... Get a game plan...

As for baseboard otlets - at least around here most were put in from the front and only require two to four flat head #4's to take the box out... (Sometimes nails) Some have brackets - but were 3-peice gem boxes. Knock the top off, pry off the sides, then the side with the bracket you sort of mangle out... Takes practice... (Die grinder will open up around the rivets if you have one) Then a new metal cut-in - in it's place.

If you are real handy with a fien tool or roto - you can cut them in where you want or where it is better for you an leave some of the old stuff depending on condition and re-feed it from a grounded circuit with a GFI - depending on the local AHJ.

Then I drill from below if possible right near the box. While I DESPISE those flexibl 6' bits - they do work and suck at the same time, but also take some practice, as well as some learn by mistake time. I have drilled into other buildings by accident with them - and all but refuse to use them.

If this is an 1800 balloon frame you may even drop down from above. Sometimes real easy.
 
L

LeeB

Member
Location
California
How to approach knob and tube rewire.

How to approach knob and tube rewire.

Hey Charlie,
I would try to analyze how the relationship with the owner will be after months of rewiring this house and did I want the job.

The owner needs to be told that the house does need to be rewired top to bottom and that most insurance companies will not insure knob & tube homes.
And yes there will be patch!

I would do an accurate takeoff and then add at least 10-15% contingency unless they are willing to go time and material with a not to exceed.
Clarify who will be responsible for patch and paint and quantify all your devices. Also add a clarification that there may be some hidden junction boxes which will be treated as extras if you go with a firm fixed price.

The home definitely needs to be rewired and you should convince her that you are qualified to do it correctly.

Good Luck - LeeB
 
highendtron

highendtron

Senior Member
LeeB, you are right on! I just finished rewiring an older AL home with new cu. The cost and time overrun was significant. I shudder to think how much higher a K&T house would be. Not being able to make holes or to plan for the patching costs would make accurate bidding nearly impossible. I don't know if I would ever take on another complete rewire job without figuring out how to charge for the associated extra time and costs.
 
B

broadgage

Senior Member
Location
London, England
A bit of lateral thinking re ceiling lights and not cutting holes in walls.

Run new cables, to code, from the load center to the lights, all concealed in the attic/roof space.
To switch the lights, retain the knob and tube switch drops and original switches but energised at only 12 volts, via a 0.5 amp fuse, this to control the lights via relays mounted in the attic space.

Alternativly consider radio operated switches, these require no wireing between the wall mounted switch and the line voltage relay in the attic.
 
G

guschash

Senior Member
Location
Ohio
Charlie you didn't say if this was single or two story house. If this is single story house shouldn't be that bad with crawl and attic but two story a little more planning and work. If it is a two story, the wiring in the ceiling might be ok to leave. The last k & t job I did the house had a leak and had to re-plaster. The ceiling was open so I checked the k& t and it was good, insulation was sound. Now I didn't megger the wires which would be the only way to really know.
 
Charlie Bob

Charlie Bob

Senior Member
Location
West Tennessee
thanks for your in-puts. I'm fixing to go back to this place with my digital camera and take pics to share with you all. The house is a two story house, brick house with sawmill lumber everywhere. Some of the knob and tube can be saved, but ineed to research as to how is the best way to connect it to new romex. (read about it but forgot) Now if i do that i'll have to put GFCI breakers at panel box. Oh I'm putting a new 100 amp panel box. This K&T is only on a small section of the house. So this will be enough. ( They have another 2 200 amp panels in basement.)
With a new panel box on the firs floor i could use crawl space, i assume. Now ceiling is what worries me!!!
 
C

Cold Fusion

Senior Member
Location
way north
Charlie Bob said:
.... It's goona required some serius work to rewire. The lady almost cried and told no cutting walls period.!!! ...

Question is or are:
1-How would you all handle this one.?
2-You all like my crawl space idea?
3-Are you all glad is me and not you??? :smile:
Click to expand...
1-How would you all handle this one.?
I always figure I'm in the business of figuring out the most cost effective method to get the customer what they want - not telling them what they can and can't have. Generally, if they have the money, I can figure out how to build something that looks and acts just like what they asked for. From your responses, you're on the same track.

"Yes maam. I absolutely understand your love for this beautiful house. I have an excellent crew of highly qualified craftsmen and while we can't do perfection - we can get very, very close. The first thing we are going to do is sit with you both and plan this job out for minimum disruption. You want the look and feel you saw when you bought this house and that is what we are in the business of providing."

You can say that with a straight face - it's true after all. Get them involved in the planning. Don't promise perfection. Remind them the house has settled since it was built and sections could be under stress. Just the opening up of the boxes could cause a crack. And you are prepared to repair using period apropriate techniques.

So, here are a couple of things I have used in the past on similar jobs:

I have hired an old retired cabinet maker that couldn't work very many hours per day and over-paid him plenty to fix the wood trim I screwed up. It took him a while, but it looked right at perfect when he was done.

Low voltage switching (late 70s job): All the switch wiring was 3C-#20 thermostat wire. That really eased the wiring installation up the walls.

X-10 controls at the lights and fans (mid-80s job): switches were on a console - -I don't remember if there were any rf controls on that job or not.

Battery operated, remote rf switches in the walls - receivers at the lights and fans (late-90s job): I had to buy several brands to find the ones that were good quality. As I recall, I ended up with a Leviton that worked well.

2-You all like my crawl space idea?
yes

3-Are you all glad is me and not you???
Well, I don't do that kind of work for hire any more. But on the other hand, one good thing is you will have to be careful about washing your hands. I have heard there is alot drug residue on $100 bills these days and with any luck you will be making a lot of trips to the bank:smile:

cf
 
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