Specs on House Plans

[zacnelson]

Hi, I have the following specification on my house drawings, which I can't even begin to decipher!

`Service Pipes to be located at a distance not closer than 45 degree incline from their invert level the base of the footing/slab, away from any proposed footings'

What on eath does this mean? And is it referring to plumbing service pipes or electrical service pipes?

Thanks,

Zac

[echnidna]

It refers to all pipes.
From the edge of the building imagine a line going into the ground at 45 degrees.
The pipes must be outside that line.

[zacnelson]

Thanks for the quick response Bob. What about my sewer waste pipe, which needs to go through one side of the footings and out the other side - are there any regulations about this? (I'm building an extensions out the back of my house with strip footings, not a slab).

Regards,

Zac

[echnidna]

I don't think they'll allow the sewer pipe to run through the footing itself

[zacnelson]

That's interesting... I would have thought that was unavoidable in most cases, even in a new dwelling, especially one with a slab, how could they have any waste pipes that don't exit the house area without passing through either a slab edge beam, a slab internal beam, or a strip footing?

[zacnelson]

Maybe I should clarify - when I said my waste pipe needs to pass through the footings, I meant roughly at right angles or 45 degrees, ie only passing through the footings for about 40 or 50cm, you may have thought I meant it would be going right through the core of the footings for many metres in a parallel direction

[thebuildingsurv]

the note is just there to ensure any service pipe excavations do not undermine the footings or the footings do not place any loading on the service pipes. Technically the 45 degrees should be taken from the bottom of service pipe trench to the bottom of the footing.

[zacnelson]

I have drawn a quick diagram to show where the waste pipes are in relation to the strip footings for my house extension. Is it allowable for these pipes to pass through the new footings? The pipes are already there, so the plan would be to poor the concrete footings with the pipes in place.

[thebuildingsurv]

yes thats fine just use some lagging or expansion foam aroung the pipes, if you have any spare trench mesh put it around those areas.

[zacnelson]

Ah, that's good news, I was getting worried there for a minute. So even that pipe on the right side which goes through the footings at an angle will be okay?

BTW thanks again for your generous assistance I don't know where I'd be without this forum

[wonderplumb]

A sewer pipe that passes through a footing must do so at an angle no less than 45deg, so anywhere betwwen the right angle and 45deg, to make provision for this (this is only if the internal drainage is to be done after the footings are poured) I usually put a piece of 6" pipe through the footing which will give room for your 4" drain to pass through with ease, if you were to put a piece of 4" in and try to join on either side chances are it will get knocked out of place during the pour, concreters arent typically gentle on pipes, and it gets worse if they use a pump and start dragging around a vibrator!
But if the internal drainage is done first be sure to wrap it HEAVILY in expansion joint foam, and while they pour it wouldnt hurt to have either yourself or even your plumber there to keep an eye on the pipe as it will float as the concrete goes in.
As for the distance from footings for your trench Ive dug up a diagram for you to look at,