Tunnel under footing for sewer/water?
The house I’m moving into doesn’t have a waste stack in the basement and I’m looking to add one in the future if I choose to relocate/resize the septic system. Can I tunnel the 4-inch waste pipe under the footings? Are there any general guidelines to doing this? Do I need to go under the footing a certain depth? I plan on bringing the water line under the footing also, but it’s on 1-inch. I don’t see it being a big concern.
Replies
i dont see any reason not to do as you say , just make sure you can make grade to septic . you can also chip a hole in the stemwall out to accomidate waste pipe
The grade won't be a problem. The side I want to go out slopes away from the house. It's very well suited for it. I just don't want the footer to crack where I tunnel.
If you are concerned about undermining the footing you can always tamp/pack the dirt back into the hole around the pipe.
If you do it in stages you can get it just as tight as when you tunneled it out.
It helps to have it the right moisture level. To dry and it doesn't pack well and to wet it just is mushy. "There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."Will Rogers
Cut a sleeve a few inches longer than your footer is wide out of the next pipe size up and pour concrete around the sleeve. Mix it on the dry side and tamp it well until you have it at or above bottom of existing footing.
They can't get your Goat if you don't tell them where it is hidden.
That sounds like a good idea. I might sleeve it at the very least.
I might be paranoid, I think the new sewer pipe will be at least 2 feet below the footer.
Josh if you are two feet below it should be no issue, no need for a sleeve. If the line were in direct contact with the footing a sleeve could be of help. But what type of soil are you dealing with, sandy soil might collapse as you dig, firm soil will stay in place under the footing and you can just tunnel through and tamp some dirt back in around the pipe. If the footing has rebar in it that helps more.Wallyo
Edited 4/16/2009 11:31 am by wallyo
Good 'ol North Carolina red mud/clay. I think it'll stay in place just fine. I've never done it before, and just wanted to cover my bases.
We tunneled under a footing of a bank to put in the pnuematic ducts and electric conduit for the drive thrue. The tunnel was huge, about 4' wide and 14" high, and we just used sand as the fill untill we got 3-4" above all the pipe. Soaked the sand down a little then finished the fill with the digging spoil and compacted it as we went up.
That bank had a heck of lot of more weight baring on the footing than any house, and to my knowledge there has never been a problem. No cracks have shown up in the past 30 years that would indicate anything settled where we tunneled.
JoshRountree: You shouldn't have any trouble with the sewer pipe, but a water line has to be a certain depth, check your local requirements, luck.