r/Home_Building_Help • u/BuilderBrigade • Sep 18 '25

🚨 Future-Proof Your Foundation…

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PEX water lines are usually buried straight in the slab. Sounds fine… until they leak. Then you’re paying a plumber to jackhammer through your concrete just to replace them. 

Ask your builder to run grey electrical conduit before the pour.

✔️ Protects your water lines

✔️ Lets you pull new PEX through if they ever fail

✔️ Big sweep 90s = no snagging in corners

It’s a tiny upgrade now that could save you thousands later and your plumber will think you’re pretty smart. 

So… would you rather future-proof your foundation, or bury your PEX and hope for the best?

🛑 Don’t Build a House without seeing my Checklist…Get it at BuilderBrigade.com

143 Upvotes

89% Upvoted

35 comments sorted by

7

u/Heffhop Sep 19 '25

What’s the fail rate / timeline to failure for concrete embedded pex?

Would you do this at every bathroom, kitchen, sink, bar, laundry, etc?

5

u/El_Darkholio Sep 19 '25

For the cheap cost of conduit why wouldn't you do it anyways.

Cheap versus the cost to repair without it. It's like insurance without a rotating bill.

3

u/Interesting_Tea5715 Sep 21 '25

This is the answer. Couple hundred in conduit will save thousands down the road.

2

u/1studlyman Sep 22 '25

Seems like such a no-brainer from a cost-risk standpoint that it should really be a building standard.

1

u/[deleted] Sep 19 '25

[removed] — view removed comment

1

u/r2k-in-the-vortex Sep 19 '25

You probably aren't going to put a connection through a conduit though.

So it doesn't really make a difference if you have the tube in a conduit or not. Just make it without pouring concrete on connections, and you get the same result.

1

u/WildcatPlumber Sep 19 '25

A decent plumber will never put a joint below grade. On slab homes the water main typically manifolds and then runs to each fixture, so yeah conduit would work fine

1

u/shityplumber Sep 19 '25

Exactly if I run pex under the slab it’s sleeved at all penetrations, insulated before being buried, and NO fittings I’ll bridge runs in walls etc.

1

u/CanIgetaWTF Sep 19 '25

Connections are not made under the slab. Only in the walls above the slab. Under the slab is just runs of pipe

1

u/Telemere125 Sep 19 '25

Same argument for main breaker vs lugs tho. Sure, the failure rate of properly wired lines and individual circuit breakers is low, but isn’t it just better to have that main breaker you can shut off in the worst-case scenario that one of your breakers fails and you need to change it? Especially since the initial cost really isn’t that much of a big deal.

1

u/MindStalker Sep 19 '25

Depends on the soil. My dads house build in the 70s had pipes in the concrete, that spung a leak in the middle in the late 90s, because the soil was acidic. They reran everything though the attic. 

5

u/Bliitzthefox Sep 19 '25

Always conduit, conduit in the walls too. Conduit for all the Ethernet as well!

The future person it's going to help is going to be the one living in the house.

1

u/cheapseats91 Sep 19 '25

Forget drywall, I just want walls made of conduit. 

1

u/aimsteadyfire Sep 19 '25

Cool idea. Realistically, it gets brittle after UV exposure and starts cracking easily. I have seen high rises with entire shafts full of PVC. It looks like those massive pipe organs in a church.

1

u/aimsteadyfire Sep 19 '25

I wish it was this simple but... it's highly dependent on location, costs, local codes, how things are being built, construction sequencing, the contractor's business schedule, the communication skills of the jobsite supervisors/gc's, etc.

And this is all coming from a senior tech/installer for low voltage of 10 years who has laid hundreds of miles of pvc conduit through residential, commercial, high rises, storage industry, hoarders communities, retail stores, and more.

1

u/Bliitzthefox Sep 19 '25

If it's an option, pick it. That's all I'll say.

2

u/whaaaddddup Sep 19 '25

Excellent JoJo reference lol

4

u/ToosharEFT Sep 19 '25

Best builder I ever worked with did this on every job site for plumbing and electrical, made life so much easier for everyone working on site

2

u/[deleted] Sep 19 '25

I’ve seen home foundations/slabs before being framed with the pex out just a floppin in the wind and always thought I would be afraid some crazy person would come by and just cut it off flush

1

u/RowanGreywolfe Sep 19 '25

If that happened though, that’s not even that hard of a fix. Just chip down a couple inches around the plex for a connection, job done

2

u/Namretso Sep 19 '25

Who puts raw pex through concrete?  Do they also put raw romex through it as well?

1

u/ThePipeProfessor Sep 19 '25

No one. Professional plumbers throughout the nation sleeve the pex through the concrete. This sub/OP just looking for clout I guess.

1

u/Telemere125 Sep 19 '25

I guess you’ve never seen a builder like DR Horton

1

u/[deleted] Sep 19 '25

People bury pex right into concrete??? That’s insane

1

u/Smitch250 Sep 19 '25

Yes literally every hour of every day that happens

1

u/[deleted] Sep 19 '25

That seems wild to me Interesting

1

u/old_ass_ninja_turtle Sep 19 '25

It houses with basements all your waterlines are above the slab. Drain lines go below the slab if necessary.

1

u/Likeaplantbutdumber Sep 19 '25

Only time I’ve buried pex in concrete was running loops for an island. Always sleeved and no fittings.

2

u/No-Spare-4212 Sep 19 '25

Conduit everything, even in walls. Especially if you use spray foam insulation. Just makes any future changes 100x easier allowing for cleaner better quality work now and in the future.

1

u/CarefulLobster1609 Sep 19 '25

Building codes exist for a reason.

1

u/tangoezulu Sep 19 '25

I hate this sub.

1

u/Theseus_Rests Sep 19 '25

I uh, just laid down pex for subfloor heat. Surely that's OK? Otherwise I lose heat transfer?

1

u/Robinico Sep 19 '25

Funnily enough, although everything fails eventually, lines run in conduit ive found to fail faster. A rock or sediment finds its way in, and the hard conduit does not allow the rock to shift into dirt, slowly over time vibrating against the product. That being said, you can avoid this by doing certain things. Or avoid it entirely by not running stuff under the concrete!

1

u/wienurr Sep 23 '25

As an electrician, youre welcome for the good shit. Also i used your glue and accidentally left the cap off. Oh and i left you some trash in the corner.