# pvc expansion joint on outside of house



## knomore (Mar 21, 2010)

Wow. I don't know how to even begin to visualize that. Anyway expansion couplings are for underground to structure transitions so that as the home settles the conduit doesn't get damaged. 

Also you can't put a condulet in a service lateral run and it sounds like you don't really have a clue what you are doing. I would call someone who does... before you start a fire.


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## backstay (Feb 3, 2011)

knomore said:


> Wow. I don't know how to even begin to visualize that. Anyway expansion couplings are for underground to structure transitions so that as the home settles the conduit doesn't get damaged.
> 
> Also you can't put a condulet in a service lateral run and it sounds like you don't really have a clue what you are doing. I would call someone who does... before you start a fire.


I have been putting a LB in almost every underground service I've ever done. Code
ref please.

Anyway, I just core drilled into a septic system for a two inch conduit. Dry core bit and 1/2 hour of work


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## HackWork (Oct 2, 2009)

Please write your post over in English, thanks.


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## MechanicalDVR (Dec 29, 2007)

Greg, welcome aboard! Wow where to start, first off like backstay said core drill if you are scared of busting out the cement. It sounds like a boat load more work to avoid drilling one hole.


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## Signal1 (Feb 10, 2016)

Whew!


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## MechanicalDVR (Dec 29, 2007)

HackWork said:


> Please write your post over in English, thanks.


Funny, i read that and thought it sounded anything but a Taxsachusetts accent. Maybe central southern.


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## cabletie (Feb 12, 2011)

Each change of direction would be calculated seperate. Since the service head has room for expansion, I wouldn't calculate that part of the short run. 

The 12' section would have just under a half inch of movement with a 100 degree temperature swing. The code wants an expansion fitting over 1/4". It would probably fly without one, but I would spend the $24.00 on one and not worry about having to add it later. 

The cost of expansion fittings makes threaded aluminum conduit look even more attractive. Personally I only like to burry PVC.


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## HackWork (Oct 2, 2009)

As long as you don't have the PVC running from one solid point to another, you are ok without an expansion fitting.

When you make a 90 degree bend, that's not really solid, you can have 1/2"+ of play in that if you put the strap a foot or so away from the start of the 90.


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## cabletie (Feb 12, 2011)

And the longest run is under the soffit, out of direct sunlight. Probably have no problem passing without one.


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## cabletie (Feb 12, 2011)

352.44 Expansion Fittings. Expansion fittings for PVC conduit shall be provided to compensate for thermal expan- sion and contraction where the length change, in accordance with Table 352.44, is expected to be 6 mm (1?4 in.) or greater in a straight run between securely mounted items such as boxes, cabinets, elbows, or other conduit terminations


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## knomore (Mar 21, 2010)

backstay said:


> I have been putting a LB in almost every underground service I've ever done. Code
> ref please.


What you are thinking of is not a service lateral. The utility company and the inspector will **** all over you putting a condulet before the meter base, just try it once.


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## HackWork (Oct 2, 2009)

knomore said:


> What you are thinking of is not a service lateral. The utility company and the inspector will **** all over you putting a condulet before the meter base, just try it once.


I have installed LB's before the meter a few times when working a riser around a crazy house. The city inspector doesn't have anything to do with it. The PoCo inspector was OK with it in one instance and in the second instance told me to remove the phillips head screws from the LB cover and install those 1-way screws that can't be backed out.


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## cabletie (Feb 12, 2011)

I don't think I ever needed to use an LB for a service lateral. Never thought it would be a problem either. 

Only once in PSE&G's territory did I have to use those one way screws on a trough. I know most 3R troughs come with a way to put a seal on them. Some accept the barrel locks. Around here, in JCP&L's territory, you never see a seal or lock on troughs for multiple meters. 

I have never had a problem with JCP&L and using an LB on an overhead service riser. Here's one I did a few weeks ago.


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## backstay (Feb 3, 2011)

knomore said:


> What you are thinking of is not a service lateral. The utility company and the inspector will **** all over you putting a condulet before the meter base, just try it once.


You still haven't provided a code ref. I call BS. The conduit and wires before the meter are not covered by the NEC. They are the power company's


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## frenchelectrican (Mar 15, 2007)

knomore said:


> What you are thinking of is not a service lateral. The utility company and the inspector will **** all over you putting a condulet before the meter base, just try it once.


I have done that few time before and I have no issue with it as long you do read the green or red book ( POCO reguations book ) and one POCO just gave me a single item changed to get approved is use oneway screws on the LB's.

and anything *Before* the meter box is POCO side they have NSEC that is a differnt ballpark game to deal with and most local inspectors useally dont get into this part.


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## Cl906um (Jul 21, 2012)

A U shape in a open pipe run is a form of expansion. You see pipe fitters do it on heating runs for expansion. Your run is so short that you shouldn't have to worry regardless.


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## electric3675 (Nov 22, 2016)

*re expansion joint*

well it passed inspection no problem i added one expansion joint the longest run 12.6 ft and used all expansion clips all pvc 35 ft long before meter.national grid ok with it too in the north east well at least mass everyone uses PVC 40 or 80 depending on location for above and underground services with residential above ground. commercial even sometimes i see PVC i dont I use metal for commercial one guy said you only use expansion joints for coming out of ground to meter thats not true a long run to a solid connection like a meter socket or LB not a service head there a table in code book.


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## 99cents (Aug 20, 2012)

An expansion joint in a 12' run of PVC? Absolutely not required. I might have used EMT anyway.


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## MechanicalDVR (Dec 29, 2007)

99cents said:


> An expansion joint in a 12' run of PVC? Absolutely not required. I might have used EMT anyway.


Yeah not seeing why EMT wasn't the way to go.


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## sbrn33 (Mar 15, 2007)

knomore said:


> Wow. I don't know how to even begin to visualize that. Anyway expansion couplings are for underground to structure transitions so that as the home settles the conduit doesn't get damaged.
> 
> Also you can't put a condulet in a service lateral run and it sounds like you don't really have a clue what you are doing. I would call someone who does... before you start a fire.


Actually exp coupling were invented for above ground work because of expansion and contraction. 
Then POCO's figured out they might help save meter sockets from being pulled off the house when the underground was not installed properly. 
You may want to know your **** before you dress someone down.


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## 99cents (Aug 20, 2012)

sbrn33 said:


> Actually exp coupling were invented for above ground work because of expansion and contraction.
> Then POCO's figured out they might help save meter sockets from being pulled off the house when the underground was not installed properly.
> You may want to know your **** before you dress someone down.


Yep, expansion and contraction of the conduit with no effect on the conductors inside the conduit. If you're using an expansion fitting to accommodate earth settling and conduit movement, you better make sure you have enough slack in your conductors equal to the travel of the fitting.

We put a sleeve around the conduit so if concrete is poured afterwards, the concrete can settle but the conduit stays in place (theoretically).


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## HackWork (Oct 2, 2009)

99, i'm not one to normally make loops or Mickey Mouse ears. But when using an expansion joint in this instance I will put enough loop in the conductor before the termination to cover any possible movement.


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## 99cents (Aug 20, 2012)

HackWork said:


> 99, i'm not one to normally make loops or Mickey Mouse ears. But when using an expansion joint in this instance I will put enough loop in the conductor before the termination to cover any possible movement.


Yes but you and me are one percenters. I'm just trying to educate the unwashed.


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## MechanicalDVR (Dec 29, 2007)

Cl906um said:


> A U shape in a open pipe run is a form of expansion. You see pipe fitters do it on heating runs for expansion. Your run is so short that you shouldn't have to worry regardless.


Can't really compare a heating line (@200+F) to a conduit that may or may not get exposed to sunlight or frost upheaval.


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## 99cents (Aug 20, 2012)

Just for chits and giggles, I did the calculation and that 12' piece of conduit will expand and shrink a total of about 3/8" even with the wild temperature swings we get up here.


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## sbrn33 (Mar 15, 2007)

HackWork said:


> 99, i'm not one to normally make loops or Mickey Mouse ears. But when using an expansion joint in this instance I will put enough loop in the conductor before the termination to cover any possible movement.


Actually boyfriend there is a spec from my POCO that shows how to do an underground S or loop. So mickey mouse ears are unnecessary. I will try to find it.


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## GDS (Feb 20, 2017)

Greg,
I am also from Massachusetts. You need an expansion every 6 feet if you follow the calculations in the code.


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## MechanicalDVR (Dec 29, 2007)

GDS said:


> Greg,
> I am also from Massachusetts. You need an expansion every 6 feet if you follow the calculations in the code.


You have a code reference for that one?


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## joebeadg (Oct 7, 2008)

whats an expansion clip?


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## 99cents (Aug 20, 2012)

joebeadg said:


> whats an expansion clip?


I think he just meant a normal PVC strap (which is loose enough by design to allow movement of the conduit).


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## HackWork (Oct 2, 2009)

99cents said:


> Yes but you and me are one percenters. I'm just trying to educate the unwashed.


That's so sweet.



sbrn33 said:


> *Actually boyfriend* there is a spec from my POCO that shows how to do an underground S or loop. So mickey mouse ears are unnecessary. I will try to find it.


Oh wow, I wish I knew this on Valentine's Day.


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## MechanicalDVR (Dec 29, 2007)

HackWork said:


> That's so sweet.
> 
> Oh wow, I wish I knew this on Valentine's Day.


Damn, you missed the chance for romance!:no:


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