Mud in Drain Tile

[Mark P]

This is the pipe that leads to the sump pit. The bottom of the pit has 4+ inches of mud in it. The house is 4 years old and is a very nice custom built job. I have a hard time imagining that they failed to install filter fabric. Can you think of another explination for the mudd in this drain?

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[Scottpat]

Tear in filter fabric or the pipe has pulled apart. My guess would be some missing filter fabric on the pipe.

[kurt]

Yeah, you got roots or mud. It's not so hard for me to imagine that someone left the sock off.

[Mark P]

I know there is no fix, so what do you recommend when you find this? "Keep the mud cleaned out of the sump pit."

[Scottpat]

Tell them what you found, what you think it is, what will happen and that they are screwed! You might add that it won't be an inexpensive fix.....

[kurt]

There is no fix. At least, nothing that anyone is going to actually do.

4 year old house with a perimeter system full of mud is what I call chronic; something very fundamental is way wrong.

I'd tell them that, tell them where it goes, i.e., a non-functional system in another 5 years.

I'd refer it on to someone that might be able to rod some of the mud, maybe a hydro-vac service.

[Mark P]

Here is my draft - I'm going to sleep on it and finish it up tomorrow. as always comments are welcome.

There are 4+ inches of mud in the bottom of the sump pit. There is also mud in the perimeter drain system that leads to the sump (see picture). If mud continues to enter the perimeter drain system (drain tile) it will become non-functional and that could result in water intrusion problems in the basement. Looking at the picture of the inside of the drain tile you can see the amount of mud that has accumulated in the 4-5 years since the house was built. What will it look like it 20 years? I don’t know it may not change at all or it may be completely clogged.

It is probably impossible to tell for certain where / how the mud is getting in. My first guess is that there is a tear / opening in the filter fabric that surrounds the drain, the fabric fits around the drain like a sock and is designed to keep silt / mud out, or perhaps the sock was never installed, I don’t know. There are other possibilities as well but it is all speculation. The bottom line is that if the mud continues to fill that drain tile it could easily be a major problem that will not be cheaply corrected. Unfortunately this system is buried under the house and educated speculation is all I can provide. Perhaps a video sewer scope of the drain might uncover some additional detail, but I don’t think the scope could make the 90 degree turns the drain tile makes. Another consideration would be to consult with a “Hydro-Vacâ€

[kurt]

I might make a few minor edits to some of the sentence structure, but overall, I think it's OK.

Sounds like you talking.

[Garet]

More "educated speculation" (BTW, I'm stealing that one):

A flaw in the sock (or an opening in the pipe itself) is certainly one possibility.

The sock will only trap larger particles. Ideally, the larger particles will trap slightly smaller ones, and those will trap still smaller ones, eventually building up a graded filter on the outside of the sock. At least that's the ivory tower thinking. If the soil is a uniform, fine-grained clay the filter sock won't do diddly to keep it out.

Regardless of the cause, if soil is continuing to enter the drain system then it can eventually remove enough soil from below the foundation to cause structural movement. That would take a while, but it's a possibility. Something needs to be fixed. The question remains as to what that something is.

[Rob Amaral]

Don't forget to mention the potential for 'undermining of the foundation' here. Serious issue. A professional engineer should be involved in this one. The builder set the house footings within the water table apparently.

[Jerry Simon]

Don't forget to mention the potential for 'undermining of the foundation' here. Serious issue. A professional engineer should be involved in this one. The builder set the house footings within the water table apparently.

Drain tiles are set level/in-line with the footers; setting them below the footers would be asking for this kind of trouble. Soil, at least around here, tends not to defy gravity and migrate/erode "up" into the drain tiles from below the footers.

[nookandcranny]

I saw this same issue on a house built in 1960 a couple months ago. The sump pit had several inches of mud in it. The drain tiles were actually clay pipe (tiles) and one was broken (large piece missing). I said I was unable to see how far the damage went, but recommended a qualified person evaluate the damage. My thinking is whenever soil around a structure is being removed, there is a risk of movement, whether the soil is being removed from under the footer or from the side of it. There were foundation cracks visible as well.