Pouring slab over septic line

[tractorski]

I am very interested in this thread, I have the same situation.

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[dave1949]

Another possible backup technique would be to run the existing line inside of a larger diameter and sturdy pipe. Of course you have to re-install the existing line to do this, but you will digging up the area anyways.

Seal the ends good so nothing can run into the larger pipe. If you have a problem later on, you should be able to replace the waste line by sliding out the old and sliding in a new pipe.

 

[CTMassey]

lots of good suggestions, in my opinion I would, as a couple others have said, run a spare "repair line"close to the existing line, sch 40, backfilled with 3/8 stone. If the line is from your tank to the field, the existing line may be sdr35, as sch 40 is not required(in my area anyway), fom the tank out. Large commercial buildings on slabs have intricate plumbing underneath, so it is certainly not a major issue

 

[kneedeep]

If you are sure the line to be covered is a supply line only and is not part of the Leach field it can be covered if deep enough for proper footing depth.

Supply only lines with cleanouts are under slabs everywhere. If it is part of the leach field, covering ot with a concrete slad/garage is not advisable as the ground is unstable (could be wet), will render that part of system inoperable and could cause settling /cracking of the slab.
However, the supply line needs to be Sch 40 PVC under the slab to the leach field.
Have you probed the line for depth in the construction area? Might be a good idea to locate the line direction and depth and mark accordingly for avoiding it with heavy equipment.

 

[BHD]

thirty six years ago I did just what was being discussed here, in a property I lived at,

there was no problems, until just a few years ago, my folks moved into the place when I moved out, and my mother planted some popular trees in the yard, about 15 to 20 foot from the building, now those trees have spread out roots, and apparently sent them under the building, as about once a year one needs to run a "heavy duty drain snake" type machine down the drain to clear it,

the line is belled Cast iron, if it would have been a solid and glued plastic line I do not think there would be an issue,

and the trees could be removed,

another party lives there now,

I really do not under stand the roots 20 foot from edge under the cement slab tho, as I would not think it would be that moist under there to draw the roots, (unless there was damage to the line many many years ago) before the building was built, the building or slab has not moved, there are no cracks in the slab.

 

[jgrieve]

Make sure to compact the fill properly

 

[radioman]

Many good advice and some iffys. Just like everyone says - as long the pipe is a service line to the tank or city sewers should be ok. If it part of a leeech feild, I'd contact your local septic professionals and ask them for opinions. How long was the pipe been in service when it was installed? When was last time you sent a camera in to inspect the pipe? You wouldn't want to replace it later after the slab been poured so replacing it now if it 40 years or older is cheap insurance policy after you have it scoped.

 

[ray66v]

I put my barn over the existing sewer line on purpose.

I put a full bathroom in there. :thumbsup:

 

[davedj1]

I am a builder and I wouldn't hesitate to build the garage over the pipe. Weight won't be an issue as the slab spreads the weight out enough. I've done it many times and never an issue. Think about all the sewer lines that are run across streets, under parking garages, stores, warehouses etc. etc.

 

[ilander]

it's too be avoided if you can. But if you have to, dig in a second pipe now, with the ends capped off. Use something permanant to mark the ends so you can find it in 20, 30 years. Then if the line ever fails, you have a spare in place, no digging up the slab.

I've marked beginning and endings of lines like you've mentioned. My method is to get a green treated 2x4 or 2x6, stand it vertical in the trench with the bottom end up against the end of the pipe. The top end of the board protrudes slightly above the trench. After back filling, the board can be cut flush with ground level. Finding the line end is easy, just carefully follow the board down to the bottom with the backhoe. The board will fall over, the line is exposed.

This method works great for running lines between two buildings. Start out at the first building and work your way to the second. When the backhoe front gets close to the second building, do what I said above, Then set the machine on the back filled trench and dig away from the second building until you get to the board. This eliminates the huge hole needed at the second building when digging from the side. Of course, be careful of cave ins on deep trenches.