sewer pipe under footer

Brian Mears

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Mar 29, 2002, 7:08:50 PM3/29/02

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I'm running a new sewer line under the footer of the addtiton I'm building.
What kind of protection do I need for the pipe (under the footer)?

jimk

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Mar 30, 2002, 12:43:26 PM3/30/02

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I assume that you are under a wall footing. Do not run the pipe under a
column footing!

I would suggest using a pipe as a sleeve, 2 or 3" larger than the sewer
line. Allow a void between those to pipes so that if the footing settles it
will not break the pipe. Fill around the sleeve with lean concrete up to the
bottom of the new footing.

Jim K.
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Brian Mears

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Mar 30, 2002, 4:06:40 PM3/30/02

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I can do that... what exactly do you mean by "lean concrete?" Also, can the
larger pipe be plain old plastic DWV pipe? Thanks for the help!

Brian

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jimk

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Mar 30, 2002, 7:46:25 PM3/30/02

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Lean concrete is low strength concrete 2000 psi or greater.

The larger pipe is just a form. Once the concrete is hardened, the outer
pipe isn't really doing anything. Any type of pipe is OK as long it can hold
the weight of wet concrete and as long as a void can be formed around the
sewer pipe.

I hope this helps.

Jim K.

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Brian Belliveau

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Mar 30, 2002, 8:10:54 PM3/30/02

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but it's unreasonable to place a small quantity of some other concrete mix
... for a shallow passage (just under the footing) uncompacted dirt ... has
enough give ... for deep passage ( say 12" below bottom of footing)
completely compacted fill ... that 12" deep pipe was likely in a 3' wide
trench that the excavator made for me ... also, we reinforce this crossing
... 3 x 15m bars 4' beyond excavation ... goal is to bridge any settlement
(anticipate the problem) ... sleeve can't hurt though ... we do that maybe
once a year

--
"It is not always a good idea to take any one reply to a post. Some, like
myself, know how things should be. Others know how to actually make them
come out the way they should be. And still others don't have a clue other
than some do-it-yourself experience that turned out all right to them (but
maybe not to an expert)."

Brian Belliveau

Northern Forms Co Ltd
1805 Kamview Rd
Thunder Bay, Ontario
P7C 4V2

(807) 475-0110
fax 577-0216
norf...@NOSPAMshaw.ca

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Brian Mears

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Mar 30, 2002, 8:11:02 PM3/30/02

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Sounds easy enough. I'll run it by the inspector. Thanks!

Brian

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Brian Mears

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Mar 31, 2002, 9:50:48 AM3/31/02

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Brian,

I'm not exactly sure what you're saying. Do you mean that I don't need the
concrete? This pipe will be just under the footing. I do like the idea of
the sleeve, and it's no big deal to pour a bag or two of concrete. Is there
a reason I shouldn't use the concrete?

Let's try it this way... here's exactly what I have. A four-inch PVC sewer
pipe that i'm putting in will run directly under the footer (about an inch
under). The foundation will NOT be masonry... it will be pressure-treated
wood (foundation grade of course). Therefore, the footer will be gravel.
I'm not sure if that affects anything... I still have to protect the pipe
from the weight/settling of the wall. So, given that situation, what would
you recommend?

Thanks for the help and advice. I wouldn't usually take the advice of one
person, but sometimes that's all you get! I run everything past the
inspector, and I can usually tell for myself if something will work or not,
or if it's good advice. I'm looking forward to your response. Thanks
again...

Brian

"Brian Belliveau" <brian-b...@NOSPAMshaw.ca> wrote in message
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Brian Belliveau

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Mar 31, 2002, 12:49:47 PM3/31/02

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"Brian Mears" <bmea...@attbi.com> wrote in message

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> Brian,
>
> I'm not exactly sure what you're saying. Do you mean that I don't need
the
> concrete? This pipe will be just under the footing. I do like the idea
of
> the sleeve, and it's no big deal to pour a bag or two of concrete. Is
there
> a reason I shouldn't use the concrete?
>
> Let's try it this way... here's exactly what I have. A four-inch PVC
sewer
> pipe that i'm putting in will run directly under the footer (about an inch
> under). The foundation will NOT be masonry... it will be pressure-treated
> wood (foundation grade of course). Therefore, the footer will be gravel.

Though I am not at all in favor of wood foundations bearing directly on
(gravel ? ... we would be coded to 10" or so of clean crushed rock
throughout), my intuition would be to not use concrete as was described, for
the reason that you want all parts to settle similarly ... the concrete
part won't settle, so that area will hang as everything else settles. And
the sleeve won't hurt.

Again, with my shiny polk-a-dot bias in full view, I have to wonder how such
a system can have a house bear on (crushed rock) with a 2x8 (?) sole plate,
carring the full weight of the house, but my concrete footing and wall must
be distributed over a 24" min width, to handle the extra 500 lb per lineal
foot that a 10 x 24 footing & 8" x 8' wall weighs. I have done footings for
p/t walls ... on undisturbed soil, with 3" passages every 4', 2 x 15m rebar,
filled flush with crushed rock (no weeping tile required)

p.s. have you noticed a small thread dealing with pressure treated
this-n-that ? Ya must have big ones to open up to that can of worms ! ;-)

--

Brian Mears

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Mar 31, 2002, 4:00:55 PM3/31/02

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I see your point with the settling of the concrete differently...I'd have to
agree with you on that. Hadn't thought of it that way. I'll go with a
sleeve and no concrete, if the inspector agrees.

I don't quite understand the concrete vs. PT footing thing either... but
it's approved by code, it's easier for me to put up, and it'll certainly
outlast the rest of my house (built in 1910 without a footer). So, I won't
worry about it.

And yes, I did see the thread(s) on killer PT wood. I'll take my chances...
perhaps radon, lead paint, or asbestos will get me first.

Thanks again, Brian. I'm sure I'll have lots more questions in the near
future... looking forward to your input.

Brian