Physical Damage

[Red Wiggler]

The term "Physical Damage" is referenced many time in the NEC, but is there any type of "standard" the defines "Physical Damage"?

Isn't this determination left up to the discretion of the installer? One hopes the ruling body that has jurisdiction over your installation agrees with you. It seems to be a very subjective issue, and could cost money to redo the work if an inspector believes the installation is subject to Physical Damage.

Any help?

 

[iwire]

The term "Physical Damage" is referenced many time in the NEC, but is there any type of "standard" the defines "Physical Damage"?

Nope.

Isn't this determination left up to the discretion of the installer?

IMO no as the inspector does not have to have the same opinion as the installer.

 

[Hendrix]

The term "Physical Damage" is referenced many time in the NEC, but is there any type of "standard" the defines "Physical Damage"?

Isn't this determination left up to the discretion of the installer? One hopes the ruling body that has jurisdiction over your installation agrees with you. It seems to be a very subjective issue, and could cost money to redo the work if an inspector believes the installation is subject to Physical Damage.

Any help?

Check with the AHJ first, then there won't be a problem.

 

[raider1]

Check with the AHJ first, then there won't be a problem.

I agree, if there is any question as to if something is subject to physical damage a call to the AHJ would be advised.

Chris

 

[petersonra]

Like many things that are vaguely worded, it is best to get some kind of interpretation up front from the interpreter.

To be honest about it, I have gotten some very pleasant surprises when I have asked what something vaguely worded means.

Probably more pleasant than unpleasant ones.

 

[macmikeman]

There are some inspectors who have power in their eyes. If they can see the wiring after the walls are up it is subject to physical damage.....

 

[e57]

There are some inspectors who have power in their eyes. If they can see the wiring after the walls are up it is subject to physical damage.....

Some might even claim the very act of putting walls up might hide the damage cause by putting the walls up.... Themins you guts to watch out for....

 

[don_resqcapt19]

There are some inspectors who have power in their eyes. If they can see the wiring after the walls are up it is subject to physical damage.....

That is my position. All wiring methods that are visible after the building is complete and some that are not visible after the building is complete are subject to physical damage.

 

[inspector 102]

I view "subject to physical damage" as follows:
Exterior wiring or conduits within 18" of finish grade unless located in a parking lot, then 36" above grade.
Interior wiring that does not follow a framing member and properly secured. If a wire runs perpendicular through a stud space in an unfinished area, it needs protected. Exception: floor joist spaces that are a minimum 6'8" above finish floor.
All roof top installation.
Each inspector will be different until it is spelled out in the code.

 

[Hendrix]

I view "subject to physical damage" as follows:
Exterior wiring or conduits within 18" of finish grade unless located in a parking lot, then 36" above grade.
Interior wiring that does not follow a framing member and properly secured. If a wire runs perpendicular through a stud space in an unfinished area, it needs protected. Exception: floor joist spaces that are a minimum 6'8" above finish floor.
All roof top installation.
Each inspector will be different until it is spelled out in the code.

I have failed many unfinished garages with NM running perpendicular to studs at waist height.

 

[macmikeman]

Around my back yard if it is above 8' from floor or grade, then its "not" *
considered subject to physical damage.


*unless of course if it does happen to get "damaged" and hence would suddenly become a code violation during the follow up inquiry....:roll:

 

[K8MHZ]

I asked an inspector about this one day. My question was whether a particular installation was considered subject to physical damage since it was near an alley. The conduit was 48 inches from the edge of the alley. Without looking, the inspector said that since it was more than 36 inches from the alley, it was not considered to be subject to physical damage.

Then, I took him outside and showed him the smashed 2 inch PVC that was damaged by a snow plow.

He changed his mind and we ran RMC in place of the PVC.

My feeling is that anywhere there are snow plow drivers, anything within 20 feet of a plowable area is subject to damage, and that's an average, not a maximum.

 

[cowboyjwc]

I would agree that "subject to physical damage" is a very tough term to define.

How many of us have gone on a service call where all of a sudden something stopped working and one of our first questions is "have you hung any pictures or added any moulding?" Why? Because we're thinking someone ran a nail through something, but we would never consider NMC in the wall "subject to physical damage".

I would usually say that if it's an exposed wiring method, with some exceptions, that it's "subject to physical damage" of some sort or another. Would I call it is an entierly different matter.

 

[iwire]

There are some inspectors who have power in their eyes. If they can see the wiring after the walls are up it is subject to physical damage.....

That is my position. All wiring methods that are visible after the building is complete and some that are not visible after the building is complete are subject to physical damage.

Don, honestly there is nothing we install in any location that is not subject to damage regardless of being able to be seen or not.

 

[e57]

While back I had this job of rerouting about a dozen RMC conduits after a slab saw cut all of them - even polished the ends to a diamond smooth finish - so even in several inches of concrete they can still be damaged.

 

[kwired]

I asked an inspector about this one day. My question was whether a particular installation was considered subject to physical damage since it was near an alley. The conduit was 48 inches from the edge of the alley. Without looking, the inspector said that since it was more than 36 inches from the alley, it was not considered to be subject to physical damage.

Then, I took him outside and showed him the smashed 2 inch PVC that was damaged by a snow plow.

He changed his mind and we ran RMC in place of the PVC.

My feeling is that anywhere there are snow plow drivers, anything within 20 feet of a plowable area is subject to damage, and that's an average, not a maximum.

RMC takes more abuse, but when up against vehicles it still doesn't have much of a chance. 20 feet is not a bad rule to have.

 

[macmikeman]

At least twice a year here I will get a service call out from some new carpenter guy (usually an unlicensed) fresh off the boat from California. Random phone book stuff. They will proceed to explain to me how the wildest thing just occurred, they were cutting thru a door threshold with the sawsall and hit a wire under it. Or a jamb around the door. Or a baseboard. All very common places to locate wiring in houses built here up until Hurricane Iniki. We used to have what is called single wall construction, basically all walls were 5/8" tongue and groove redwood slats.
Wiring got hidden in the above locations or run in wooden molding on the surface. Locals all know how to avoid hitting the wires but new guys don't know what is about to happen. I will admit it is very unique, but once you are used to it, you are used to it.....

 

[don_resqcapt19]

Don, honestly there is nothing we install in any location that is not subject to damage regardless of being able to be seen or not.

True..everything is subject to physical damage, but the code rules only say you can't use some wiring methods in areas that are subject to physical damage. Other wiring methods can't be used where they are subject to sever physical damage. Still other wiring methods have no physical damage restrictions on the code.

 

[iwire]

The very reason cables in walls are subject to damage is because they cannot be seen.



My only point is it is as it always has been ....... totally subjective. No one person knows what it means or can define it.

 

[M. D.]

I can't help but to be reminded of Scott's experience with SE cable services vs. ones in conduit in the aftermath of a big o'le ice storm . the cable installations fared far better than did the conduit installations, . The potential for physical damage was ,IMO , severe for both.. and yet the exposed cable was superior.