PVC emerging under a deck.

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augie47

augie47

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Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Other inspectors...
How would you approach the following ?
PVC conduit is installed to a septic pump. The conduit is 18" + below grade until it reaches a point that, when the structure is completed, will be below a deck that is approx 24" above grade.
The conduit presently "rises" from proper depth to grade at the house (footer) but that portion will be under the deck.
Would you rule that the portion less than 18" be protected by concrete, etc., or would you consider being under the deck as "under a building", or how would you rule.
The installer posts here and I told him we would see opinions other than mine.
 
cadpoint

cadpoint

Senior Member
Location
Durham, NC
There's no application for a structure above as stated here to protect any electrical install, I'll vote 2" of concrete and some depth of the run, before a pour.
 
Pierre C Belarge

Pierre C Belarge

Senior Member
Location
Westchester County, New York
If it rises from the proper depth under the deck, and the deck is permanent, I would not have an issue with the installation. The clause usually goes something like this "protection from physical damage". Where is the potential for physical damage in this instance?

Of course, unless this installation is in the LAND OF OZ. ;) Munchens and all that...:grin:
 
augie47

augie47

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Staff member
Location
Tennessee
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State Electrical Inspector (Retired)
Pierre, I want to "rule" that way, but looking at Table 300.5 I find it difficult. Where can I "hang my hat" ? by saying the PVC is under a building ??
 
Twoskinsoneman

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
Forgive me for intruding, I know you directed this question to other inspectors.

I guess I just don't know what the issue is because I'm having a tough time picturing it.

Wouldn't it normally be ok to run the PVC under the deck...like strapped under it? So if it emerges from grade then begins running under the deck what is the issue?
 
K

KevinVost

Senior Member
Location
Las Vegas
If it meets code by being buried properly and rises to grade properly and once the deck is built it is not subject to physcial damage there should be no real problem with the install. If your worried about damage, install sch 80 PVC. I believe Sch 80 is listed for locations subject to damage.
 
C3PO

C3PO

Senior Member
Location
Tennessee
Davis9 said:
Why does it have to be under the building? Are we missing something?

Tom
Click to expand...

Per table 300.5 if it is considered under the building it has to have zero inches of fill. If the deck is considered the building then it would not matter how shallow it was buried under it.
 
Davis9

Davis9

Senior Member
Location
MA,NH
C3PO said:
Per table 300.5 if it is considered under the building it has to have zero inches of fill. If the deck is considered the building then it would not matter how shallow it was buried under it.
Click to expand...

I get that but why does this pipe have to be under the building? Would a piece of 1/2" PVC need to be under a building at all times?

I would think that under a deck is not subject to physical damage?



Tom

Just asking for clarification is all.:confused:
 
Pierre C Belarge

Pierre C Belarge

Senior Member
Location
Westchester County, New York
PVC is permitted to be buried.
PVC is permitted to rise from underground to emerge from grade.
PVC is permitted to be installed laying on grade.

PVC is not permitted to be installed where subject to physical damage unless:
It is protected from physical damage
or
It is Schedule 80





[is it proper to write, 'laying on grade' or 'lying on grade'?]
 
H

hardworkingstiff

Senior Member
Location
Wilmington, NC
augie47 said:
The conduit is 18" + below grade until it reaches a point that, when the structure is completed, will be below a deck that is approx 24" above grade.
The conduit presently "rises" from proper depth to grade at the house (footer) but that portion will be under the deck.
Click to expand...

How many linear feet are above 18" and below the dirt but under the deck?
 
augie47

augie47

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Location
Tennessee
Occupation
State Electrical Inspector (Retired)
the ditch is not backfilled yet.,,,,at a point about 8 ft from the building (footer) the pipe begins a rise from the 18" until it enters the building.

Depending on fill, it may be on top of the dirt or barley buried at the shallowest point. The deck isn;t there, but it appears it will extend to the point where the PVC is 18".

I guess part of my concern is that it runs adjacent to the sewer line.
As "hardworking" states, I may be too hung up on the "letter of the law".
I don't see physical damage being in issue as much as a future dig for the sewer pipe etc and a conduit not being installed per NEC.

"letter of the law" can be important in "lawsuit".
 
R

realolman

Senior Member
I can understand what the OP doesn't like about this install. Seems to me the whole deal is a judgement call.


The conduit presently "rises" from proper depth to grade at the house
Click to expand...

It not only "rises", but "runs" as well. I think it's underground... too shallow.
I think I would bury it 18" to where it came straight up somewhere.
But like someone else said... you can use it under the deck, can't you?

I can see it either way.:-?

I have 3 (4?) questions:

1. What exactly constitutes "subject to physical" damage anyway?
stacking firewood under a deck in cold weather?

2. If they run the conduit directly into the house, is duct seal or silicone acceptable for keeping the sewer gas out of the house?

3. Is the hand hole / septic tank a hazardous location?
 
Davis9

Davis9

Senior Member
Location
MA,NH
augie47 said:
the ditch is not backfilled yet.,,,,at a point about 8 ft from the building (footer) the pipe begins a rise from the 18" until it enters the building.

Depending on fill, it may be on top of the dirt or barley buried at the shallowest point. The deck isn;t there, but it appears it will extend to the point where the PVC is 18".

I guess part of my concern is that it runs adjacent to the sewer line.
As "hardworking" states, I may be too hung up on the "letter of the law".
I don't see physical damage being in issue as much as a future dig for the sewer pipe etc and a conduit not being installed per NEC.

"letter of the law" can be important in "lawsuit".
Click to expand...


This clears it up much better, I would say you are correct, it isn't deep enough. Some cement would do it nicely. I thought you were most concerned with the exposed pvc on the side of the building.

Tom:smile:
 
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