PVC Conduit

[Jerry Bruette]

I'm looking to run about 75 ft. of conduit, underground, from one building to another. Looking on local BORG website for conduit and fittings and I see that Southwire makes push on connectors for PVC conduit. No glue involved and they're rated water tight. They call them SIMPush. Has anyone used them or know anything about them?

[Cameron Wood]

Haven't seen that but am familiar with Sharkbite.

Sounds like a good idea (except for cost) as glued fittings in long runs sometimes don't hold.

[John Lanciani]

What do you gain? Glue is cheap and easy, and regardless of fittings underground conduit is always considered a wet location per the NEC.

[Frank Pratt]

Properly used, the PVC solvent cement will hold a fitting that will not break loose.

[roger wiegand]

They probably work just fine if they're UL listed, as noted watertight is irrelevant underground as the conduit will fill up with condensation if nothing else over a period of time. Every one I've ever taken up has been full of water. An advantage over glue would be if they're reasonably easy to undo, like sharkbites. (not that you want to be undoing the underground connections often, but I just had to do exactly that while replacing a rotted lighted sign pole). Plenty of bad/incomplete glue joints out there, they almost have to be better for mechanical strength and water intrusion from the soil.

[Cameron Wood]

What do you gain? Glue is cheap and easy, and regardless of fittings underground conduit is always considered a wet location per the NEC.

I ran electric for a hot tub recently, & struggled a bit with fittings going around trees etc.. Couldn't get the fish tape through (ream your pipe ends!) & cut one joint apart as I thought some crud must have got in there. Could have used some push-on fittings...

[Jerry Bruette]

In the video they were easy to disassemble, but they were new. They are rated NEMA4. I'm not an electrician but it sounds impressive.

[Tom M King]

Use primer first just like you do on PVC waterlines, and not only will it be watertight, but they won't come apart. I comes in clear as well as purple. I think it's mostly just Acetone, but I'm not sure. In any case it's a lot more liquid than water, and you will get it somewhere you don't want it. Wear disposable nitrile gloves.

You can heat it and bend it if stock fittings won't do what you need. There are even special heating blankets to soften it just right for such bending.

Best to keep all the hub ends going one way, and remember which way so you can easily get a fish tape through it. A fish tape will hang up going the other way.

[Malcolm McLeod]

... 75 ft. of conduit, underground, ...


... the conduit will fill up with condensation if nothing else over a period of time. Every one I've ever taken up has been full of water. ...

A tiny diversion in case it helps, but for the reason cited by Mr. Wiegand, I am fairly sure the NEC prohibits the use of NM (romex) and THN/THHN outdoors - even if run in conduit. I believe direct burial rated cable (type UF, IIRC) is called for - even if run in conduit. Perhaps a properly licensed electrician can confirm?

[Charlie Velasquez]

A tiny diversion in case it helps, but for the reason cited by Mr. Wiegand, I am fairly sure the NEC prohibits the use of NM (romex) and THN/THHN outdoors - even if run in conduit. I believe direct burial rated cable (type UF, IIRC) is called for - even if run in conduit. Perhaps a properly licensed electrician can confirm?
Just needs to have the letter “w” in the designation. Most THHN is dual rated “THHN/THHWN”

[Jason Roehl]

Just needs to have the letter “w” in the designation. Most THHN is dual rated “THHN/THHWN”

This. Running a sheathed cable (like direct-bury) in conduit is an exercise in frustration unless you way oversize the conduit. There’s really almost never a good reason to do so.

[Jack Frederick]

I can’t see an advantage in a removable fitting in underground. It is a one time thing. Dig your trench, lay out the conduit on boards across the trench, gluing as you go. Do use primer and glue. Let it set up and rest, pull the boards and lower into the trench.

[Jim Becker]

I kinda agree with Jack relative to this specific application. While a removable fitting used in the shop might be a big benefit for surface mount electrics, for example, because of the inevitable changes over time, for a buried application, it's going in the ground and will therefore be inaccessible. I honestly chose to run UF direct buried between my new shop building and the shed, transitioning from vertical PVC conduit with appropriate fittings on both sides of the run.

[Cameron Wood]

Just needs to have the letter “w” in the designation. Most THHN is dual rated “THHN/THHWN”


That had me worried, as I run THHN in conduit underground plenty, but I looked and the spools all do say THHN/THWN.

Re other comments, I don't think the point of the push-on fittings is removability, but ease of use- no glue. Putting everything together above the trench is good, except for tree roots that the conduit must run under.

[Patty Hann]

I kinda agree with Jack relative to this specific application. While a removable fitting used in the shop might be a big benefit for surface mount electrics, for example, because of the inevitable changes over time, for a buried application, it's going in the ground and will therefore be inaccessible. I honestly chose to run UF direct buried between my new shop building and the shed, transitioning from vertical PVC conduit with appropriate fittings on both sides of the run.
How deep was the run?
Is there a different depth requirement for a run not in a conduit vs one in conduit?

[Jason Roehl]

How deep was the run?
Is there a different depth requirement for a run not in a conduit vs one in conduit?

Yes. I don't recall the exact numbers, but it's something like 12" for conduit and 18" for direct-bury cable.

As for gluing PVC pipe, the best tip I ever learned from someone was to prime, glue quickly, then push the fitting on, and twist it back and forth until it locks up. That helps keep the glue distributed, and it prevents the hydraulic pressure of the glue from pushing the joint apart before it sets. It seems to speed up the set, too.

[roger wiegand]

Speaking as someone who has, twice in the last three years, needed to move a buried circuit, I respectfully disagree with those who say that ability to disassemble a buried circuit is irrelevant. I'd also say that given a saw and a couple couplers it's also no big deal to disassemble and move a glued conduit. If I'd known about these I would have used one near the base of my lighted sign to make replacing the post easier next time, but glued the rest of the ~200 ft run.

[Jim Becker]

How deep was the run?
Is there a different depth requirement for a run not in a conduit vs one in conduit?
24"+ per code. I could have done 18" in conduit. The Big Orange Power Tool had no issue making the trench more than deep enough :D

[Patty Hann]

24"+ per code. I could have done 18" in conduit. The Big Orange Power Tool had no issue making the trench more than deep enough :D

I'm sure it didn't :D

[Jim Becker]

One of the pleasures of a property that has essentially no rocks in the soil, unlike our previous property which was pretty much one big rock: the foot of supposedly one of the only two exposed limestone mountains in the state.

[Tom M King]

Below the subsoil here, it is just one big rock. Fortunately we can get 24" deep in most places.

[Jim Becker]

Below the subsoil here, it is just one big rock. Fortunately we can get 24" deep in most places.
That's pretty much what it was like at our old property, but there were many places that it was not possible to dig very far. The neighbor's back lawn was about 2-4" of soil and then solid limestone. They were truly at the head of the mountain upcropping.

[Jerry Bruette]

Part of the reason I'm considering conduit is that this run will go across a yard that will be driven on. I could bury the UF cable, but if something goes wrong with it I'll need to dig the whole thing up again to fix it. I figured if it's in conduit and the wire does something it shouldn't I'll just pull new wire.

I initially thought about pulling UF through the conduit until an electrician I worked with talked me out of it because of the problems I'd have pulling it and the size of conduit I'd need. Pulling THHN will cost about $20 more than the UF If I buy the THHN off of Amazon. If I buy the THHN at the local Green BORG it would be about $65 more than the UF.

[Tom M King]

It would be a cheap 65 bucks if you tried to pull UF wire.

[Jim Becker]

You have good justification for the conduit, Jerry, and I'd probably do that in the same situation. My run from the shop to the shed isn't in a traffic area and would rarely be crossed by anything bigger than the Big Orange Power Tool. (~2900 lbs) That advice about the difficulty of pulling UF through conduit is sound. it was "fun" just pushing it through the short risers was a pain!! (Stripping it is also a bag of laughs)

[Rollie Meyers]

Yes. I don't recall the exact numbers, but it's something like 12" for conduit and 18" for direct-bury cable.

As for gluing PVC pipe, the best tip I ever learned from someone was to prime, glue quickly, then push the fitting on, and twist it back and forth until it locks up. That helps keep the glue distributed, and it prevents the hydraulic pressure of the glue from pushing the joint apart before it sets. It seems to speed up the set, too.

12" is for residential branch circuits 20A 120V max GFCI protected, most conduit & cables is 18" except under roads & driveways which is 24", rigid or IMC metal conduit is 6", 'cept under roads & driveways which is 24", or 18" for 1 & 2 family dwellings.

[Ole Anderson]

When I ran my underground RG11 cable from the pole to house (for the fourth time in 35 years) I finally put it in 3/4" schedule 80 underground PVC conduit. Glued the joints, but I ran the RG11 as I went, one stick at a time. Not taking chances of it getting hung up on a joint.

[Maurice Mcmurry]

I got scolded by an Inspector for not using the correct glue and am now careful to use the correct glue for the various types of PVC. I used all porpoise clear on conduit, the Inspector wanted to see grey, approved for Sch. 80. I have tried pulling the wire as you go as well. I worry that the conductors will be stuck in the squeeze-out or that the glue might not be good for the insulation?

[George Yetka]

Use the pvc with couplings built in and make sure they all go the same direction as pulling through them will become harder if you hit a male end. Prime just before gluing. The primer and glue react with each other but the primer will not help if its on more than a little bit before the glue.

If you are concerned wrap some of this around the joints
https://www.supplyhouse.com/Pasco-9062-R-2-20-MIL-Pipe-Protection-Tape?utm_source=google_ad&utm_medium=Shopping_tm&utm_campaign=Shopping_TM_Returning_users&gclid=Cj0KCQjwyLGjBhDKARIsAFRNgW99PgSYIHYlilvw7Xgz yvzsmRxL0_tX-ScDpiKoFJnyE2TX8INKq_4aAogjEALw_wcB

[Thomas Crawford]

I did UF cable inside oversized conduit. We have rocky soil and I couldn't quite get 24" everywhere. It was a royal pain pulling it but with the addition of a pull box and plenty of the lubricating goop it was doable. I think I had about 85 feet with one right turn at the box and then a gentle slope to the outbuilding. I stacked old brick pavers across the top of the entire thing. It gave me peace of mind that if I go digging in the future I'm not going to accidentally cut it. I'm sure it was overkill but conduit is cheap relative to everything else. In retrospect I probably would have just sprung for the THHWN even though it saved hundreds of dollars at the time.