# Drainage  Piping  Inside  Grade  Beams



## globe trekker (Oct 2, 2012)

I have an upcoming project where the RDP has designed a (new

construction) 4" san. sewer pvc line to be installed inside "to

be poured" concrete grade beams and tied in-place to the various

steel reinforcement stirrups and other steel reinforcement with

wire, so as to prevent displacement & sagging.

I am not familiar with this type of "bedding of the piping" and am

concerned about potential damage to the pvc *(1.)* when the

concrete is placed on top of & around it, and *(2.)* contact of the

pvc piping with the steel - - i.e. pressure points on the pvc piping.

*QUESTION # 1:* Has anyone had any experience with this type of

piping installation, with the pvc piping installed inside a reinforced

grade beam type cage around it and concrete consolidated around

it?

*QUESTION # 2:* Would you be concerned about the overall

integrity of this type of installation, and if so, what code section

should I reference to address / possibly correct to another

alternative method? We are using the 2006 IPC & other I-codes.

Thanks ya`ll!  

.


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## BSSTG (Oct 2, 2012)

Greetings,

That would not be acceptable IMO. PIping is to be sleeved where passing thru beams and such. It is now popular here in Tx for any piping in grade beams to be wrapped with bubble wrap or carpet padding if it's not sleeved. That typically gives you the equivalent of a 1/2" sleeve. Works well for fittings where it's difficult to properly sleeve. I would also question why they want to do this anyway. It would require a structural engineer for an ok not to mention the expense.

section 305.3, 305.5  09 IPC

BS


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## globe trekker (Oct 2, 2012)

BSSTG,

Thanks for the input! I do not know why the RDP ( yes,

a structural & mechanical engineer) designed the piping

this way. I DO plan to send a comment letter back to

them informing them of Section 305.5 and wait to see

what their comments are.

.


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## mtlogcabin (Oct 2, 2012)

My concern would be where the pipe enters and exits the grade beam.

What detail does the RDP have to address possible movement of the grade beam while the building is being loaded (built)

That is the main reason for sleeves and arch requirements when passing through a foundation. The grade beam is part of the foundation and where the pipe enters/exits there should be some flexibity there.


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## globe trekker (Oct 2, 2012)

mtlogcabin,

The RDP's have multiple sections of the 4" san. sewer actually

designed to be inside multiple grade beams, ..inside a "reinforced

steel cage", for a lengths of 50' on one grade beam, then turns

90 deg. and a length of approx. 40', and 3 more sections of

this one san. sewer line in other grade beams.

Language on some recently submitted plans indicates that

they plan to tie the pvc piping in-place with some type of

wire (I'm guessing something akin to "hog wire") to secure

the pvc piping to the steel reinforcement over the entire

run of the piping, at 3' intervals.

In the originally submitted plans, they mentioned having

a pipe sleeve installed where the piping passes thru a

foundation wall, to the tune of one pipe size larger than the

4" san. sewer piping.   In the most recently REVISED plans,

that language has disappeared.

I'm guessing that they are not going to want to redesign

their plans for this one san. sewer line, but I do not see

how they can install a 4" pvc line, ..test it with water,

..properly bed it in and then install approved pipe

sleeving over the entire length of the run, ..inside the

grade beams.  I can see how it could be achieved if it

were only a small section of the sewer line penetrating

a grade beam in a single location, ...but over a majority

of the whole run?  

Maybe someone on this Forum can enlighten me.

.


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## codeworks (Oct 2, 2012)

seems like that piping is taking away from required concrete space in the grade beam if i'm reading right


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## globe trekker (Oct 2, 2012)

codeworks,

Yeah, you're reading it right!  That's a whole separate issue!

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