I recently had an unfortunate incident while digging for a deck footing and ended up hitting my sewer line. After clearing that up, I noticed one of my footing holes is about 3 inches away from the clay sewer line. I'm curious—what do you think is the minimum safe distance I should keep between my concrete footings and the sewer line? Any advice would be appreciated, cheers!
3 Answers
I had a similar issue, but with a concrete sewer pipe. My engineer recommended wrapping the sewer line in foam or bubble wrap to leave a gap with the concrete footing. I ended up pouring the footing right on top of the pipe, but it’s worth noting that my footing was on pin piles driven into solid glacial till, so sinking shouldn't be a problem. Just make sure to consider your soil conditions!
You can definitely build close to the sewer line, but just don’t go lower than it. You want to avoid any downward pressure on the pipe. If you’re putting in piers, just remember to draw a diagonal line from the post to ensure they don’t intersect with the sewer line, and you should be good!
If you’re dropping on the surface, make sure that diagonal line stays clear. It’s all about keeping everything independent!
I’d recommend keeping about a foot away from the pipe horizontally. This way, you ensure that the footing doesn’t cause any compression on the pipe. You can break the rule a bit if you use a pipe sleeve that’s two sizes larger than your sewer line. I’m not sure about the specific codes, but the general guideline is to keep at least 12 inches of clearance for anything underground, just to be safe!
So you're saying there's a chance?