Drain pipe depth

I know that sewer and drain pipes must be protected from freezing & damage but is there a minimum depth that drain pipes must be buried? I cannot find reference to anything in the IRC and I do not have a UPC available. Here is a photo of an efficiency apartment sewer line from an inspection yesterday.

No. There isn’t.

Thanks Jeff…that supports my research as well…I couldn’t locate anything regarding depth. Slope, diameter, materials, yes, but that’s all.


In most jurisdictions around this area and the standard for burial depth of exterior utilities is 18"-30" deep. Exception would be sewer and water where it would have to be below the frost line.

Now in Texas where there is no frost one would think that any utility would be at least 18" deep even if it is merely to protect it from external damage.

There might not be a specific code requirement for this particular item, but the Health Authority of your area does regulate existing private sewage disposal systems. I would check with them for any amendments under the Plumbing Code or variances they might have. Permits and designs are required for Private sewer disposal systems.

If this is connected to public sewer, I would check the requirements with the Public Sewer District for their regulations on this.

In either case, this dose not look right to me, but that is my opinion.

Marcel :slight_smile:

Marcel, I agree that it doesn’t look right. I wrote it up along the lines of “The sewer drain line from the efficiency apartment should be protected from damage and freezing. I recommend consulting with a licensed plumber to determine the proper method.” I too was thinking I would find a reference to a 18" or so depth but, like Jeff says, I couldn’t find that anywhere. I just really wanted to know for future reference in case I were to see this situation again.

If that is indeed a waste line, it appears to be going uphill and should be protected from mechanical damage in that particular traffic location.

I would think that the bottom line on this topic would be something similar to this:

Sewer Line Protection*

You own and are responsible for maintaining the sewer line running between your home’s exterior and the street. It’s highly vulnerable to clogs and blockages… from tree roots, pipe collapse and common waste, which can happen at any time – usually without advance notice. In most cases, those lines were put in place when your home was originally built and may have gone through years, or even decades, of seasonal changes, root invasions, or cumulative blockages.




Excavation…line clearing…site restoration…sidewalk/street repaving…can all cost thousands of dollars.

Your Responsibility

As a homeowner you own and are responsible for paying for repairs to the water and sewer lines running from your home to the street and plumbing repairs that occur within the home.


If the water line between your property line and your home begins to leak or break from aging or the natural effects of seasonal changes, you could find yourself with an unpleasant surprise in the form of a large bill for repairs. The same holds true for clogs and blocks in the sewer line that runs from your home all the way to the sewer main under the street. And you could find yourself with a clogged bathroom sink, a blocked or overflowing toilet, or a burst frozen water pipe.
The unanticipated expense for these repairs could easily run into the thousands for a single home water or sewer line repair. Most homeowners are not prepared for that kind of expense and most homeowner policies do not cover repairs of this type, since they are considered normal wear and tear.

Marcel :slight_smile: :slight_smile:

No, it drains from right to left and does go downhill. There might be an optical illusion if the slope looks wrong to you. I did recommend protecting it though.

Yep, I agree and those are good graphics. I saved those for future reference.

In many cases, the slope of the line is determined by the relative elevations of the house and utility sewer line to which it connects. As I understand it, there should be a uniform slope from one point to the other, so the depth will necessarily have to vary and may be pretty shallow near the house.