Residential re-wire estimating

[BMacky]

I've been offered an opportunity to remove knob and tube wiring from the attic and exterior walls of a two-story SFD so that the insulation contractors can come in and do their blown-in insulating.

What suggestions does anyone have on how to estimate this type of work?
We have the OK to open walls as needed within reason. All of the wiring comes from the panel in conduit to individual j-boxes, then the branch circuits start with the knob and tube from the box. It's newer K&T, the TW (if I may) type insulation, not the older rubber and cloth insul.

Anyhow, not that that matters much, but what I really need is something like a count of switch boxes, fixture boxes and receptalces and then assign a unit price or something of the sort.

I'd specifically love to hear from someone who has done this a few times and has some system down that seems to produce a decent figure.

I appreciate any input and can give more detail if necessary.

Thanks!

 

[Lcdrwalker]

I usually just cut it back to the point where it is concealed and abandon it inside the walls and ceiling. Remember that when you're doing a major rewire, receptacle placement has to be to the code currently in force. I've found that I will have to add quite a few to comply with todays requirements.

 

[electricmanscott]

Remember that when you're doing a major rewire, receptacle placement has to be to the code currently in force. .

According to who?

 

[SEO]

Always check with the local inspection authority as to what they will require. It could save you a lot of headaches and money.

 

[480sparky]

I always inform the customer that short of actually doing the work, there's no accurate way to tell how many hours and how much material it's going to take to do the job.

At best, I suggest yo provide a 'Not To Exceed' price. Make a list of all the work that needs to be done. Rank them according to safety. Attack the serious violations first, then work your way down the list. If something takes longer than anticipated, you may not get the entire list done. But some things will go quicker than you think, so it may work out in the end.

'Tis better to make sure the work you've done makes the home safer rather than be window dressing.

 

[macmikeman]

I bid 3x my normal price per opening. I don't hear back from a lot of the bids I give out for rewiring. I am so happy I bid 3x per opening when I do get selected, cause it is 3 times the work and expense to do the jobs. This comes from many repeat experiences in rewiring houses. Dozens. Others may disagree. Edit to add: No half measures for me, if I am asked to "rewire", then 100 per cent rewire is what they get, specially when knob and tube is the existing.

 

[Kdog76]

At best, I suggest yo provide a 'Not To Exceed' price.

At BEST?... 'Not to Exceed' is nowhere near my 'BEST'. Sometimes, though it is a necessary evil.

 

[Rewire]

alot depends on the house an easy house I figure 1 -1 1/2 hour per opening plus material on a 2 story I would go 1 1/2 -2 hr per opening . Include time for layout and cleanup. One guy can usually complete a room in a day thats removing all old devices and fixtures replacing them with new and adding any required receps and cleanup,moving furniture included.

 

[BMacky]

Great! Thanks for the valuable information. I appreciate the response.

 

[bauler]

3X normal time is probably about right. Is the house empty or occupied? Makes a lot of difference. When someone lives there they don't want to be without power one extra minute. You'll hear, when will the power be back on? Besides all the other delays and problems you'll run into with a occupied house.

Are you doing the patching or is that someone else's job? I use a large hole saw when I can't fish through a wall. Makes patching easy. You can use the drywall from the same hole, or cut a new piece of drywall with the holesaw to patch plaster. If you can cut the hole so you can catch a piece of wood, you will have something to screw the patch to.
Use hot mud to patch. Be sure you make it clear who does the patching and painting.

I would plan on going all the way or don't do it. It will take longer to do anyway. I've always laid out plugs according to current code, never had a problem with inspectors.

Try to sell the customer on the safety and the convenience of more plugs. I've sold several panel change outs that way.

Good Luck...

 

[bullheimer]

i tell them a couple of things but the basic standard price i give is $10/square foot.

if there is insulation in the attic they must have the insulation contractor remove it. i think they wanted $300 to do it.

this was for a one story house. a 2 story you MUST have carte blanche to make holes anywhere as big as they have to be and you are NOT responsible for repairing them. since my back started giving out and i cant do one of these anymore without killing myself i raised my rates to $12/sq.ft. that gets them talking about just adding the circuits they need for whatever they want to plug in. at $500 per circuit last year, lowballers have cut it down to $350. i am doing a microwave ckt tomorrow for that. ugh! blow in insulation too. i told them an extra hundred dollars for that. hell you have to!

old knob and tube wiring is still just fine and dandy for the most part. if you don't want to do the whole house then tell them that. the primary problem with it, well there are two things. first and formost is they were and are designed to be in free air, NOT with insulation all over them. sometimes rats eat them but not so much. the other problem is that those buttcracken old timers put half the house, if not the whole house, lights and recepts and everything, only only one or two circuits!! so overloading would take place because of the way it's laid out, even with new romex or even conduit. that is why you can tell them they just need to add new circuits. because it is a royal PITA to run new lighting. it's like those wires' insulation is always fried from 100W bulbs in non vented fixtures. you will have to cut holes in the tops of walls and edge of the cielings to fish your wire in there.

one option you can try with the owners therefor is to have them leave the lights as they are as much as you can. then you can remove all the recepts from the old ckts by running the new wire to them under the house. disconnect the knt wires and wirenut them in the box. also, if you want to turn knt into romex you will need a PLASTIC box for the hot and nuet to run into and connect to romex. i always save some of the knobs i remove so when i do this, i can attach the old wire to a knob within 8 inches of the plastic box, eliminating the need for a connector. however new plastic boxes have built in wire (cable) clamps so you could go 12"s. not sure it matters as the 8/12" fastening rule is under the romex (nmsc) section. but i'm rambling....

so for a 1000 sq ft house charge a minimun of ten thousand dollars. you will have to add smokes too if you do a whole house. yes, here if you do a complete rewire, panel and all, the code is like a brand new house. you can save yourself alot of work with the smokes by buying the new wireless linked ones for $50 each only (as far as i know) at home dePOT. late

 

[electricalperson]

rewiring old houses can be fun and exciting sometimes but you have to be very careful. they used to support fixtures off of old gas pipes. in my 1941 electricians handbook it shows an illustration of this. these jobs can be a piece of cake in most parts while on the other hand they can be an impossible nightmare. ive done jobs that had no attic or crawl space yet they want receptacles everywhere and no holes in the freshly painted walls. you have to use your brain and think of ways to do this without anything on the surface or walls being cut. its a challenge sometimes but possible

 

[iaov]

If I have to be carefull about putting holes in walls the price goes way up!

 

[willco]

I have performed many Knob and Tube Rewires, both full and partial re-wires; and to answer your first question you must be aware that many Knob and Tube circuits may have originated in the attic with the original service fuses in the attic. This was a throwback to the early days of electrical used in houses which was for the most part for lighting purposes only. These fuses (original service) might have been removed with the next generation of electric service that was installed on a lower level. The older generation electrician could be back-feeding the original lighting circuits. More often than not you will find that circuits in the attic will also serve the lights in the kitchen two floors below. In other words cutting attic lines may shut down first floor ceiling lights which can be much harder to re-wire. So take it from me make sure you have that contingency figured in.
Pete