Replies

1. 
   BobKovacs | Aug 14, 2005 01:48am | #1

   You use short enough nails that any items properly located in the center of the studs can't get hit.  You note in your proposal that you aren't responsible for items too close to the stud edge.  Lastly, when you remove each sheet for replacement, note the location of any potential problems and work to avoid them.

   Bob

1. 
   ~~~~butch | Aug 14, 2005 02:01am | #2

   Thanks for the quick reply <note the location of any potential problems and work to avoid them.>You nailed it on the head.......but if you got sheathingunderneath your siding, you still can't see what's there.You have answered my question though, That I need to make theclient aware of the potential problem, but I wanted to seewhat the take was here as I've never thought to address this problem before and wanted to know how to handle itcorrectly.

1. 
   spindrift67 | Aug 14, 2005 02:07am | #3

   You would not have that problem of sheathing underneath. The t1-11 is the sheathing.

1. 
   ~~~~butch | Aug 14, 2005 02:21am | #4

   Not around here, I guaranteee that there is sheathing under thist-1-11.

2. 
   4Lorn1 | Aug 14, 2005 07:03am | #5

   I would think it would be best to pad your bill enough to cover any likely number of minor difficulties. Depending on the cost of living in your area I would think half a days average labor cost would cover it. Around here a couple hundred dollars.

   Making sure your insurance is paid up and prepared to cover the extreme cases is also a good idea. If you hit a water line and it goes unnoticed and floods the house the insurance company is there to take up the slack.

   You can also take precautions to limit the risk. Water and drain lines will tend, but not without exception, to be located in the normal places. Bathrooms, kitchen, water heater. Gas lines are usually limited to somewhere near where they are needed. Electric cables are more widespread.

   It would pay to survey the house. Check the crawl spaces for the location of utilities. Check attics and inside of cabinets for further clues as to how the water and gas lines are run. Don't forget ducts and central vacuum lines, or anything else that comes to mind, although these would seem much less at risk.

   The electrical lines can be tracked with a non-contact voltage sensor. Some of the better pen sized units would do the job. Some stud locators have a decent version of this feature. Better equipped electricians often have trackers that will locate live lines reliably if not perfectly. Operator experience is a big factor in how well any of this works out. Through a couple of inches of wood I think I could localize the lines to within an inch or so.

   Keep the electrical lines live when nailing. You want to have lights go out, the breaker to trip or there to be some other sign that you hit a cable. In fact it pays to have a lamp operating at the end of each circuit so that you can see in some obvious manner that a circuit has stopped working. You might consider nailing a sheet up and sending in a helper to see if all the light are still running. If everything was working before and now a circuit is off you have some idea where to look for the fault. The most dangerous situation is a damaged cable that gives no sign but cooks quietly in a wall while people sleep.

   I think that a detailed survey, electrical line tracking and some care will lower the risk of hitting anything to acceptable levels.

   Just brainstorming here but if I worked with carpenters who did this sort of job a lot, as a support electrician, I would be tempted to rig some devices to sound off with a fault. It wouldn't be too difficult to rig a GFI at the beginning of each circuit that runs through the affected area. Perhaps rigging a power-loss noisemaker to both the GFI at the beginning of the circuit and one plugged in at the farthest point of the circuit.

   Effectively covering all likely faults. H-G or H-N would blow the breaker. H-G, a high resistance fault, or N-G would trip the GFI as would current diversion outside of the cable. Severing the hot or neutral would cut current to the noisemaker at the far end of the circuit so it would sound off.

   Off the top of my head I'm not sure how I would cover a clean severance of the ground wire, a nail cutting the ground without diverting current or contacting the neutral or ground, but IMHO such a fault would be a very low probability. If such an event occurs consider buying a lottery ticket and getting debriefed by a priest.

   Such a portable set of GFIs and noisemakers, figure a maximum of four circuits, would run a couple hundred dollars, including labor, to rig up but once the kit was assembled it would be reusable for years with only a need to replace the batteries every year or so. It would also be useful for other situations. I have made up a couple of the noisemakers and found them quite useful. They can be made to serve many functions.

   I doubt such an extensive deployment would be cost effective in a limited, one-time-only, case. I would think a good survey, common sense, a voltage detector and dumb luck would be the best approach.

1. 
   ~~~~butch | Aug 14, 2005 01:35pm | #6

   Wow! This place is awesome, thanks for that insightful reply.You made me realize the seriousness of this.<no sign but cooks quietly in a wall while people sleep.> That single statement was an eye opener, and something I hadn'tthought of. I'll be contacting my electrician to see what hewill charge me if I still want to do this.