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Discussion Starter · #1 ·
We were asked to quote a lighting job for an existing parking lot, the lot has no existing pole lights and we are quoting to install approximately 800' of 1" PVC and install 9 pole bases. After reviewing 300.5 it appears I need to be 24" deep with the PVC. My question is that I would like to only trench no more than 1' deep, anyway to get away with this if we backfill the entire ditch with concrete? Trying to avoid compaction issues with the backfill. Thanks
 

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Sure, you can cover the pipe with 2" of concrete--T300.5 Col. 3
 

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I don't see how you get around the 24" of cover rule. Column 3 says 24" without concrete.

And by the way, that's 24" of cover -- not a trench 24" deep.

Bottom line is that if you're dealing with non-dwelling vehicular traffic, you need 24" of cover, with or without concrete.
 

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Discussion Starter · #4 ·
Pharon said:
I don't see how you get around the 24" of cover rule. Column 3 says 24" without concrete. And by the way, that's 24" of cover -- not a trench 24" deep. Bottom line is that if you're dealing with non-dwelling vehicular traffic, you need 24" of cover, with or without concrete.
Yeah, I understand it that way also, just wanting to make sure, looks like the only way around the 24" depth is if you encounter rock
 

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Why the aversion to 24"? It doesn't take any longer to go 24" deep than 12" if you have the right equipment. Not to mention, it will also be code compliant. For what it is worth, I also recommend plowing instead of trenching to eliminate backfill.
 

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Discussion Starter · #8 ·
btharmy said:
Why the aversion to 24"? It doesn't take any longer to go 24" deep than 12" if you have the right equipment. Not to mention, it will also be code compliant. For what it is worth, I also recommend plowing instead of trenching to eliminate backfill.
It's in an existing parking lot with blacktop, the parking lot runs down hill to the store, just thought if we could go 12" deep and fill with concrete it may be less of an issue with the ditch acting like a French drain back to the building vs. going 24" and using crushed limestone. Just trying to avoid water issues. Also I've never seen a plow that could cut through the blacktop without making a huge mess, we just figured a saw cut and trencher, I'll check about the plow. Thanks for the input
 

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directional drilling will solve all of your problems. Or you can tamp your dirt backfill in lifts, then you don't have to worry about the limestone draining, and the concrete heaving differently than the blacktop during frost periods.
 
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