Thread: Main Waste under footing?

I recently ran across a PVC waste line that exited the structure directly undernieth the footing, in a perpendicular fashion. Is this allowed. I was under the impression that the "zone of compresson" under a footing could not be compromised. Additionally, the IRC [2604.4] states no trenches [parallel to] to bottom of bearing footing within 45 degrees. This situation is not parallel to, but my client wants to know what code is in question.

Similar Threads:

• Charred Copper wires in Main Panels
• Transformer & Low Volt Wiring in Main Panel
• Indirect waste lines...
• General Electric Split Main Panel
• Double at Main

Originally Posted by John Thompson

I recently ran across a PVC waste line that exited the structure directly undernieth the footing, in a perpendicular fashion. Is this allowed.

Yes, it is allowed, but ...

From the 2006 IRC. (underlining is mine)

- P2603.5 Pipes through footings or foundation walls. A

ny pipe that passes under a footing or through a foundation wall shall be provided with a relieving arch; or there shall be built into the masonry wall a pipe sleeve two pipe sizes greater than the pipe passing through.

Passing through a foundation wall - a relieving arch or a sleeve two pipe sizes larger.

Passing under a footing - a relieving arch.

Jerry,

How exactly is "a relieving arch" defined?

dirt over the pipe in an arched style works for me!

Originally Posted by Joshua Hardesty

How exactly is "a relieving arch" defined?

Joshua,

"dirt over the pipe in an arched style works for me!" is not correct.

The footing needs to be designed to arch up and over the pipe, with the steel in the footing, in such a way as to transfer the load "above" the pipe location to the sides of the pipe location, so that there is "no load" directly on the footing pressing vertically down toward the pipe.

Jerry,

So from your description, a relieving arch will never be added after the footing is already there, it's got to be engineered into the system when it's built.


How'bout this then: When a basement is built with a poured cement wall, and is core drilled, does that still need a sleeve?

And furthermore, I have a question about the material of said sleeve. I know its supposed to be two pipe sizes larger than the pipe itself, so if I have to run 1/2" pex through a wall, how much protection is that 1" pex really going to offer?

I was under the impression that the sleeve was for abrasion protection, not compression. I could be wrong.

If that is indeed the case, then does the corrugated pipe that is sometimes put into foundations/footings (instead of coredrilling afterward) provide adequate protection? (assuming it's properly sized)

Originally Posted by Joshua Hardesty

Jerry,

So from your description, a relieving arch will never be added after the footing is already there, it's got to be engineered into the system when it's built.

Correct.

How'bout this then: When a basement is built with a poured cement wall, and is core drilled, does that still need a sleeve?

Now you are mixing terms.

We *were* talking about going "under footings", now, though, we *are* talking about going "through foundation walls" ... and the code covers that - sleeve it with a sleeve two sizes larger.

And furthermore, I have a question about the material of said sleeve. I know its supposed to be two pipe sizes larger than the pipe itself, so if I have to run 1/2" pex through a wall, how much protection is that 1" pex really going to offer?

I don't know about using PEX as a sleeve, but, for the moment, let's say it is okay.

That PEX is simply there to make sure that the pipe does not do three things: 1) abrade or have dissimilar material contact; 2) allows for the sleeved pipe to be totally free of pressures on the foundation wall' 3) allows for expansion and contraction of the sleeved pipe.

jerry,
your statement about requiring a design for running a building drain under a footing is special. pay an engineer to say how to accomplish something done everyday as standard practice? the codes require protection of piping and dirt over the pipe provides adequate protection. maybe there is a reason that you feel engineering is required that i am not aware of ?

Originally Posted by brian schmitt

your statement about requiring a design for running a building drain under a footing is special. pay an engineer to say how to accomplish something done everyday as standard practice?

It may be "done everyday", but then so is "multiple tapping" terminals in electrical panels ... does NOT make it correct, though, does it (just because it is "done everyday").

the codes require protection of piping and dirt over the pipe provides adequate protection.

Brian, I suggest you read the wording in the code, then post it here, showing us which part says that.

maybe there is a reason that you feel engineering is required that i am not aware of ?

"that i am not aware of ?"

Yep, it's in the code.

Joshua,

Attached is one structural engineers design for when a pipe goes through a footing. This one relieves the pressure "around" the pipe as the pipe actually "goes through the footing" (not under it, and not through a foundation wall). The "relieving arch" effect, though, is required so that no load from above is placed on the pipe.

There are other design which are more like 'arches' for when the pipe goes "under" the footing (instead of through the footing as in the attached).

From the Commentary on the IRC.
- P2603.5 Pipes through footings or foundation walls. Any pipe that passes under a footing or through a foundation wall shall be provided with a relieving arch; or there shall be built into the masonry wall a pipe sleeve two pipe sizes greater than the pipe passing through.

(Commentary)

❖

Any pipe installed within or under a footing or foundation wall must be protected structurally from any transferred loading from the foundation wall or footing. A relieving arch or a pipe sleeve can be used to provide this protection. Where a sleeve is used, it must be two pipe sizes larger than the enclosed pipe. This space will allow for differential movement of the pipe. See Commentary Figure P2603.5.

Attached as drawings from the Commentary.

From the Commentary in my previous post:

"A relieving arch or a pipe sleeve can be used to provide this protection."

That, to me, means that the pipe used for the sleeve (used to provide the protection intended - "must be protected structurally from any transferred loading from the foundation wall or footing" - would thus need to be at least sch 40 steel pipe.

Even PVC, being must stronger than PEX in providing protection, *will not* protect from the loads being described.

jerry,
pipe thru a wall or footing is a prescriptive approach clearly defined in the code. under a footing was not shown in your rather impressive cut and paste display of commentary which is not code in the enforcement world. you continue to have your take and i will have mine! i enjoy the opinions of others and learn from them often....but not this time

Originally Posted by brian schmitt

pipe thru a wall or footing is a prescriptive approach clearly defined in the code. under a footing was not shown

Brian,

Not sure what part of (underlining is mine) ...

Originally Posted by Jerry Peck

- P2603.5 Pipes through footings or foundation walls. Any pipe that passes under a footing or through a foundation wall shall be provided with a relieving arch; ...

... you don't understand.

jerry,
what is a relieving arch comprised of. is there a definition of how to make one and what type of material is it made of? dirt,concrete,wood? is there a definition in the i.p.c.? we still use the u.p.c. and it simply calls for sleeving or protection of piping thru or under walls and the commentary(not code) just shows a pipe run thru the dirt under the footing. so jerry i don't understand why a relieving arch can,t be made of dirt when a pipe is run say 12"s below the bottom of the footing?splain it to me

Originally Posted by brian schmitt

i don't understand why a relieving arch can,t be made of dirt when a pipe is run say 12"s below the bottom of the footing?splain it to me

Brian,

I will *try to* 'splain it to you where you can udderstan' it.

"why a relieving arch can,t be made of dirt when a pipe is run say 12"s below the bottom of the footing?"

Q. Okay, first, what is the footing bearing on?

A. The soil beneath that footing.

Q. What bears on that footing which is bearing on that soil?

A. The entire load of the house above that part of the footing, and, if under a load bearing column, more of the structure's load that what is just above that footing area.

Q. What does that soil below the footing bear on?

A. More soil beneath that soil.

Q. What would happen is that soil beneath the soil beneath the footing were removed, or allowed to collapse?

A. The soil above would cave in to the void created by such collapse.

Q. What would happen to the footing above when that happens?

A. The footing above would not have its designed soil bearing support and could shift, allowing the structure to shift.

Q. What if the structure did not shift and the only thing which happened was that collapse of the soil beneath the soil supporting the footing?

A. The pipe in that collapsed soil has collapsed due to the load on it from above, and, while the structure may not have suffered any noticeable effect, the collapsed pipe is now blocked with soil.

Q. What does a blocked sewer pipe cause?

A. Sewers to back up and cause your cup to runneth over.

And your bowl too.

jerry,
a 3 or 4" pipe in the dirt under a concrete foundation and the concrete will collapse and will kill thousands? put down the pipe! i think a foundation can span a few inches even without rebar in it. you are going to get a migrane trying to convince me on this one. and what is a relieving arch made of o wise one?

Originally Posted by brian schmitt

a 3 or 4" pipe in the dirt under a concrete foundation and the concrete will collapse and will kill thousands?

Brian, Brian, Brian ...

You've got to read all of the post ...

What happened to that pipe which allowed that soil collapse?

THAT IS WHY there needs to be a relieving arch above the pipe.

jerry,
you have not answered my questions and cannot! this battle of wits with an unarmed man is tiring. later.

I do believe I've seen pictures of foundation failures (cracked and settling) where a waste pipe was run under the foundation. A hollow plastic or cast iron pipe can't support much lateral force. I mean, putting the IRC aside for the moment, this is a plain common sense issue not to mention elementary engineering statics. Or maybe its a common sense issue because I remember some of the statics and dynamics course taken in the olden days when slide rules were king.

Hey JP - do you think some people go out of their way to just jerk your chain? I don't always agree 100% but I do think you serve as a valuable source of information and comment to the inspection community.

Originally Posted by Stuart Brooks

Hey JP - do you think some people go out of their way to just jerk your chain?

Stuart,

Yep, daily.

All I can do is respond with code and other "official" information to allow them to quench their thirst, however, I cannot make them drink at the fountain.

I don't always agree 100%

That's okay, I don't always agree with me 100% of the time either.

but I do think you serve as a valuable source of information and comment to the inspection community.

Thanks for the kind words ... after Brian's feeble attempt at flinging wet noodles, it nice to see there are people who actually understand the "... plain common sense issue not to mention elementary engineering ...".

Don't need to be apart of the "footing" conversation, but doesn't there need to also be a "wrap" of piping that extends through a poured floor? Example was new construction, plumbing extending through the garage poured floor (not the footing). I believe that there should be a "wrap" of some kind visible at the floor between the pipe and the concrete and I'm having a devil of a time finding the write up to back up my memory. Any help would be appreciated...

Thanks,
Reis

Originally Posted by Reis Pearson

doesn't there need to also be a "wrap" of piping that extends through a poured floor?

From the 2006 IRC.

- P2603.3 Breakage and corrosion.Pipes passing through or under walls shall be protected from breakage. Pipes passing through concrete or cinder walls and floors, cold-formed steel framing or other corrosive material shall be protected against external corrosion by a protective sheathing or wrapping or other means that will withstand any reaction from lime and acid of concrete, cinder or other corrosive material. Sheathing or wrapping shall allow for expansion and contraction of piping to prevent any rubbing action. Minimum wall thickness of material shall be 0.025 inch (0.64 mm).

I am an engineering geologist/geotech engineer. At some depth, the soil will bridge and carry the load, that is the principle behind unlined, unreinforced tunnels, as well as rabbit holes. I found the following code reference http://dallascityhall.net/pdf/Building/PipesThrough.pdf

It states that if the pipe is 2 inches or more below the footing and ocvered with soil, an arch is not required.
Cheers

Originally Posted by Jeff Laird

I am an engineering geologist/geotech engineer. At some depth, the soil will bridge and carry the load, that is the principle behind unlined, unreinforced tunnels, as well as rabbit holes. I found the following code reference http://dallascityhall.net/pdf/Building/PipesThrough.pdf

It states that if the pipe is 2 inches or more below the footing and ocvered with soil, an arch is not required.
Cheers

Jeff,

Welcome aboard.

IF you read that linked document you will see that it is incorrect at its base assumption.

I understand what you are saying about soils, which is what the angle of repose is about, and the plumbing codes require trenches to not be within the area of a 45 degree angle from the bottom of the footing.

However, the premise that document is based on is incorrect, it even includes the code language, then incorrectly repeats it - which is where their problem begins. They then expand on that problem by making improper assumptions, ending up totally flawed.

First, let me say this
I am not a C-O-D-E Inspector, I would like to ask any of the inspectors this.
Have you ever seen the relieving arch installed where sewer mains go under the footing?
I would even like to hear from any jurisdictional C-O-D-E inspectors that have ever seen one installed per the drawings supplied.
What you will normally see is the sewer ditch filled with gravel to the bottom of the footing from approximately 5' outside to approximately 2 feet inside the footing


Have a great day
Tim

I am not a C-O-D-E inspectors but at most times a C-O-D-E designer. Our notes call for sleeved pipes for lines running through footings, structural engineers usually have a generic detail for the arched support over piping through the footers and I have seen sleeved pipings on many commercial inspections I do in the line of my job.

I'd laugh and call out the hack if I didn't see one or the other for protection of the pipe, especially in my area where cast iron is almost never used and PVC is the pipe of choice.

I am not asking about, through the footing, I understand the sleeve requirements, I am asking about going under

Thanks

Tim

Originally Posted by Tim Saunders

First, let me say this
I am not a C-O-D-E Inspector, I would like to ask any of the inspectors this.
Have you ever seen the relieving arch installed where sewer mains go under the footing?
I would even like to hear from any jurisdictional C-O-D-E inspectors that have ever seen one installed per the drawings supplied.
What you will normally see is the sewer ditch filled with gravel to the bottom of the footing from approximately 5' outside to approximately 2 feet inside the footing


Have a great day
Tim

I am a C-O-D-E inspector (building, plumbing, mechanical and electrical) and a C-O-D-E plans examiner (building plans examiner, not plumbing yet) and I D-O S-E-E relieving arches and sleeves installed, and when not installed this C-O-D-E inspector shows them the code which requires it and a relieving arch or sleeve IS installed before it is signed off.

Both through the foundation wall and under the footing.

[quote=Jerry Peck;87200]Jeff,

Welcome aboard.



I understand what you are saying about soils, which is what the angle of repose is about, and the plumbing codes require trenches to not be within the area of a 45 degree angle from the bottom of the footing.
codeman,
the code i enforce says the 45 degree angle applies to "trenches deeper than the footing of any building or structure and PARALLELING the same shall be at least 45 degrees therefrom." no mention of PERPINDICULAR?

Originally Posted by brian schmitt

no mention of PERPINDICULAR?

Ummm ... Brian, the pipe cannot go THROUGH the foundation wall or UNDER the footing UNLESS it is run PERPENDICULAR to same.

The 45 degree information was to address THE STRUCTURE'S LOAD ON THE SOIL AND THE SOIL'S PRESSURE pushing downward, and that one DOES NOT WANT ... *ANY* ... pipe to be supporting the soil or the structure above.

THUS BOTH APPLY.

Brian, THINK ... THINK ... before replying and trying to jump down my back, you will look much more graceful and intelligent that way.

Originally Posted by Jerry Peck

I am a C-O-D-E inspector (building, plumbing, mechanical and electrical) and a C-O-D-E plans examiner (building plans examiner, not plumbing yet) and I D-O S-E-E relieving arches and sleeves installed, and when not installed this C-O-D-E inspector shows them the code which requires it and a relieving arch or sleeve IS installed before it is signed off.

Both through the foundation wall and under the footing.

Thanks

Have a great day

Tim

Originally Posted by Jeff Laird

I am an engineering geologist/geotech engineer. At some depth, the soil will bridge and carry the load, that is the principle behind unlined, unreinforced tunnels, as well as rabbit holes. I found the following code reference http://dallascityhall.net/pdf/Building/PipesThrough.pdf

It states that if the pipe is 2 inches or more below the footing and ocvered with soil, an arch is not required.
Cheers

JEFF,
what works in dallas,texas (wherever that is?) does not apply to flahdah or the rest of the jerry,s world it works here!



Brian, THINK ... THINK ... before replying and trying to jump down my back, you will look much more graceful and intelligent that way.
jerry, you certainly have a thin skin for a self proclaimed code inspector. i'm sorry for any mental anguish i may have caused.not!
[/quote]

Originally Posted by brian schmitt

i'm sorry for any mental anguish i may have caused.not!

Brian,

See? I knew I could count on you for a reply like that.

There are two things I can count on here, and one has been letting me down the last few days:
1) Jim Port responding like you do to my posts.
2) You responding like Jim Port does to my posts.

You are both such a blast that I can never wait to see what foolishness come out in your next posts. I must say, though, that at least you do seem to have some knowledge about things.

Originally Posted by brian schmitt

what works in dallas,texas (wherever that is?)

That does not say it works in Dallas, only that is how it is to be done there.

does not apply to flahdah

That "commentary" (for lack of a better word) does not even match the code section quoted above that commentary.

Kind of like the TREC SoP, way off track.

jerry,
there is a smiley after my slam,much like a certain ec jerry does! lighten up a little, take a deep breath and count to 1

Originally Posted by brian schmitt

take a deep breath and count to 1

1/2
3/4
7/8
15/16
31/32
63/64
127/128
Where to heck is that "1" thingy???

Hello all. I think the code is very grey. Nobody asked the guy who originally started the post what the elevation of the pipe is in relationship to the bottom of footing. If the top of the pipe is the same or higher than the bottom of footing then a relieving arch is needed. If the top of pipe is lower,at least a couple inches, than the bottom of footing than you wouldnt need a relieving arch. The point is that the footing can not touch the pipe.

Originally Posted by john conner

Hello all. I think the code is very grey. Nobody asked the guy who originally started the post what the elevation of the pipe is in relationship to the bottom of footing. If the top of the pipe is the same or higher than the bottom of footing then a relieving arch is needed. If the top of pipe is lower,at least a couple inches, than the bottom of footing than you wouldnt need a relieving arch. The point is that the footing can not touch the pipe.

Incorrect.

The code is not a gray area about this at all ...

... if a pipe passes UNDER a footing ... the footing REQUIRES a relieving arch.

The point is that NO LOAD from the footing above the pipe be carried on the pipe, thus the relieving arch to take the load to the side away from the pipe.

Just like a pipe is not allowed to be buried within a 45 degree angle of the bottom of the footing when run parallel with the footing ... so no load from the footing is placed onto the pipe.

That is also the reason for a pipe passing through a foundation wall requiring a sleeve two pipe sizes larger ... to remove all load from the pipe and let the pipe be 'free floating' as it passes through the load bearing foundation wall.