View Full Version : Who's problem is this?

AZ Contractor
11-03-2007, 01:34 PM
I'm a GC working on renovating an old restaurant into a new restaurant.

Plumbers came in and saw cut the slab to run their new sewer lines. Just below the slab in one area was a bunch of electrical conduits feeding parts of the building and some exterior lamp posts and signs.

Some of the conduit was just below the slab and some of it was 2" below the slab. The plumber's saw cutters cut through the conduits and wires inside and the electrician is saying its going to be an expensive fix because he has to pull all new wires.

What do you guys think?

11-03-2007, 01:42 PM
It falls under "Unforseeable Circumstances".

If this was a new restaurant all the way around, then the electrician that installed the conduits should know where they are, and the plumber should have asked.

But since it's an existing structure, the original electrician is most likely not the one doing the remodel, and therefore not available to tell the plumber to be careful.

I'm sure there's going to be a lot of finger-pointing on this, so it depends on how your contracts are written.

AZ Contractor
11-03-2007, 02:01 PM
Did the depth requirements of conduits change over the last 15-20 years?

How deep under slab are conduits supposed to be? These were grey plastic conduits.

11-03-2007, 02:25 PM
I believe that the conduits only need to be covered by 2" of concrete. They can even be in the concrete if thats what is needed. This is the plumbers fault all the way. Anytime you cut into concrete bad things can happen, you just have to be ready for it. Normally this is why you only cut the concrete about half way through. Then jackhammer it out.

11-03-2007, 02:56 PM
On one job the contractor told me there were no conduits, but there were and they got cut, then he back charged me for fixing them. But the safest thing would have been to have line locators track the underfloor piping so you could avoid them. At this stage, you can try to pass it off to the owner or general contractor, but since they are the ones paying you you don't have a lot of leverage if they decide to deduct it from your contract. Then your insurance may cover it.

11-03-2007, 03:11 PM
It's the reponsibility of the owner.

Stuff happens.

The same thing could happen to the pluimbing if the electrician had to saw cut.

Fix it and move on.

Sometimes SPECS state that all UG conduit must be 12-18" to avoid things like this, but it's not code.

Where is the restaurant? I'm in AZ too.

11-03-2007, 04:17 PM
This is clearly the fault of the person doing the cutting. It is the responsibility of the person doing the cutting to ensure that they have knowledge of any impending dangers.

As to the depth of the conduit it is clear that the work was being done on the inside of the building so the conduit was under the building.

Table 300.5 states any installation that is in a raceway and under a building does not require any ground cover.


11-03-2007, 04:47 PM
Table 300.5 states any installation that is in a raceway and under a building does not require any ground cover.

By todays' standard, yes. But when was the conduit originally constructed, and what codes were in force at the time?

The "Under A Building" row of the table didn't appear until the 1990 NEC. From 1978 to 1987 there was an exception to T300.5 concerning depth, which concerns the thickness of the slab itself. In the 1975 edition, a pad of 2" or more allowed only 6" to be subtracted from the values in the table.

Prior to that, burial codes were in Section 230, and only referred to types of raceways allowed below grade. PVC and RMC were about the only accepted raceways in general use for this purpose at the time, and back then PVC required 18" (no exceptions that I could find) and the Article for RMC only stated it was allowed for direct burial.

Dunbar Plumbing
11-03-2007, 05:03 PM
In KY the only time DWV piping underground in concrete is only when it passes through the concrete vertically, no exceptions.

In my opinion, it would seem to me that if they are allowing conduit to be buried almost flush with the floor surface, that has to provide structural integrity issues knowing that anything that size *2-9/16" for 2" PVC CONDUIT* in a 4" slab is taking away all strength, basically separating slabs and throwing control joints out the window. The piping itself would serve as the control joint which would not be good.

Dem plumbers I swear, they do this stuff all the time and look at what the electricians have to go through. :o

To me, I think the electrician was lazy and didn't want a shovel in their hand to do the first rough. Otherwise that piping would of been considerably deeper to protect the above situation from happening.

Looks like somebody gets to try out their liability insurance for the first time...
Popcorn! Peanuts!

Bob NH
11-03-2007, 07:26 PM
I have been is a position like this as an owner and the one thing that applies is that, in the absence of a specific contract provision, I know that I am not responsible.

The general contractor is usually responsible to the owner for all of his subcontractors, and it is his responsibility to sort it out with the subs.

AZ Contractor
11-03-2007, 08:07 PM
Well I have a clause in my contract that protects me from "unforeseeable conditions" like this. I'm not worried about that.

The customers are good customers of mine. This is the 3rd restaurant we're building together. I try to be as reasonable as I can with them.

I think its one of those unfortunate incidents that you can't predict by looking at the surface of a concrete wall or floor.

I just can't figure out what to do yet.

Yeah I'm protected by my contracts for situations like this and I can make my good customers pay for the repair. On the other hand I'm disturbed the plumbers saw cutters went so deep. This was a tight area and they were using hand saws and I know its EASY to feel when you've went through the concrete and are into the subsurface.

All these guys do all day is cut concrete. Wouldn't you think they would have a technique to cutting to prevent situations like this?

Dunbar Plumbing
11-03-2007, 11:00 PM
From my years of cutting concrete, no, I can not tell when I'm cutting through PVC or electrical wires unless the blade starts a rooster tail of sparks...

then I'm thinking I hit rebar.

A saw cut is designed for two reasons when dealing with concrete removal:

One to give the ability to start an opening in concrete that's been machined down by a trowelling machine. << That concrete is 5 times harder to remove, especially if it isn't old. It's also done to unlock the concrete when its busted out.

Two is to protect from spider cracking the concrete beyond the area to be removed, protect structural support of slab for equipment/pole supports.

To me it was a situation that would of happened with any plumber that came in and saw cut that area; ALL of them would of expected the conduit to be deep into the subgrade under the slabs, not embedded in them.

11-04-2007, 05:41 AM
I can't imagine why they didn't just run a sniffer across the floor "just in case" to see if there might have been any electric stuff under there. Even absent that, a few cautious cuts to determine the slab depth, then "cut for effect" to go only to the bottom of the slab would have made more sense.

11-04-2007, 06:05 AM
Depending on the size of the facility it is feasible to have a fair idea where conduits run.

We would look at the panels and if any conduits leave the bottom of the panels, it is a major enforcement of "MURPHY's LAW" that you will hit one conduit. It is also possible to get an fair idea where the conduits run by where they enter the deck and where they exit.

Seems the GC and the plumber (possible the electrician if he had any idea the slab was to be cut) over looked a few basic common sense steps.

11-04-2007, 10:18 AM
In the long run it is not economically feasable to spend a couple hundred dollars on a good locator every time you saw cut.

Mark it, cut it and fix it when necessary.

It is just like trenching. You are gonna hit something somewhere. Just use your best judgement to avoid it and fix it when you can't. It's not the cutters responsibility unless something was marked. Saw cutters cut concrete. It's what they do.

You can spend time and money to prevent a lot of it but in the long run, stuff happens.

As GC I am thinking that YOU should have considered this possibility and discussed it with the owner. I bet you will next time :)

I've had to repair some conduit due to a saw cut. I didn't charge them cause it was mine. It was 150 degrees out when I was doing the UG so it MAY not have been as deep as it should. Your restaurant isn't in Mesa, is it? :)

11-04-2007, 02:50 PM
Mark it, cut it and fix it when necessary.

Rip Leave and tear philosophy, why not use a bit of intuitive thinking and try at least to determine if conduits are present. I mean the price of copper is not going down.

At a minimum on this project the OP mentions there is lost time, wages, material, and a lot of finger pointing and arguing.

11-04-2007, 08:59 PM
Rip Leave and tear philosophy, why not use a bit of intuitive thinking and try at least to determine if conduits are present. I mean the price of copper is not going down.

At a minimum on this project the OP mentions there is lost time, wages, material, and a lot of finger pointing and arguing.

Agggghhh...read the post.

I said "Just use your best judgement to avoid it and fix it when you can't". Doen't this imply intuitive thinking?

I also tried to point out that I believe there will be a net loss of resources if every sawcut was properly located @ probably 200 bucks a whack.