Ok to use my own dirt rather than shop bought gravel?

My basement project is moving on. I have old field stone walls that leak in places. My solution is:
1) Dig a trench along the problematic walls
2) Install a 4 inch drainage pipe at 2.5’ slope
3) Install a sump pump
4) Install a waterproof barrier up to ground level
5) Build a stud framework
6) Add services
7) Insulate
8) Finish

Thanks to permies, I’ve already thrashed out the plan and got some great feedback.

Today’s question is about step 2. It’s recommended to back fill around and on top of the drainage, allowing the free flow of water into the pipe. Rather than buy gravel, I’ve discovered that my soil is half gravel, half sand with very little silt. (I’m waiting until tomorrow to see if there’s any clay, but it will still be a tiny percentage.

I dug out and inspection pit, 2ft square, next to my basement wall - all the dirt is uniform, no noticeable layers. It’s very loose, sand and gravel. I decided to do a proper analysis and filled half a jar with dirt from the hole. I put this is a salad spinner and here’s the results.


Smaller stuff


Pea gravel

The smaller stuff I tipped back in the jar and mixed vigorously with water as per standard soil tests. I let it sit for a minute and here’s what appeared:


An hour later and the silt has settled out - about 1mm


The clay comes next but that’s 24 hours away and I’m not expecting much. The soil has zero cohesion.

So I’m thinking, I don’t need to buy any gravel? I could just backfill with the soil I already have.

On a side note:

I don’t think the moisture probably will make it into the pipe 99% of the time and just sink down below the house. I am however planning for freak weather events. I’ve been in the US three years and experienced three, hundred year events. In NJ we had 8 inches of rain in one hour. The same storm dumped a foot of rain in 24hrs where I’m now living. There was no flooding here as we’re high up on the side of a gentle valley and the local geology is sandy and rocky. So I’m planning for a big water pulse through the ground. As time goes buy, I’ll be harvesting the roof water and building a nice big permaculture sponge but until then I need some security and who knows what the next owner will do.

Hi Ed;
You can make that work  But you will want to screen it to size and then wash it.
The washing part is very important.
You will want the larger gravel 1/4-3/8" not the little stuff.

Buying sized washed gravel by the truckload is a quicker way to go.

Thanks Thomas, great reply.

Sometimes I go down the rabbit hole of doing and making everything myself and then end up having too much to do and not enough time.

I think this might be one of those times where I should just buy the washed gravel. I don’t have a way to screen the dirt without building something or anywhere sensible to wash it. The basement dirt wont go to waste as I can use it in the garden to mix with compost.

You can fit a 'sock' to the pipe to prevent fines getting in and blocking it over time .

John C Daley wrote:You can fit a 'sock' to the pipe to prevent fines getting in and blocking it over time .

Do you have any suggestions for materials to use as a sock?

Oh, sorry most manufactures of the slotted tube supply  it fitted to their product , ask at your supplier.

Here is an alternative view I have not heard of before, from; https://onlinewaterproofingshop.com/geotextile-around-drainage-pipes-a-new-house/
"When researching about installing agricultural drains you will find some books recommend that you place a geotextile in the trench before the initial gravel and then wrap the geotextile over the gravel afterwards. Its something I used to do.

You can also buy agi pipe with a geotextile “sock” around it like this:
Geotextile around Drainage Pipes – A New House, geofabric for sock on ag pipe The idea is that the geotextile prevents the gravel, or the pipe getting clogged with fine materials.
I DO NOT  recommend this as practical experience has shown that what happens is:
If you wrap the gravel in geotextile the geotextile actually collects all the fine particles on its surface.
This means geotextile will get clogged up stopping the water getting to the gravel and through into the pipe.
or Normally you wrap your Aggi drain with geotextile and then back fill with sand /gravel. Then the geotextile “sock” actually collects all the fine particles on its surface acting like a filter. The “sock” clogs up stopping the water getting through into the pipe and away.
It far better to just go for a 10 mm or smaller gravel surround. Any fine material that gets through the gravel will be that fine it will easily pass through the slot and hopefully get washed down the pipe."

Comment from John Daley- I have seen the sock used with 10mm gravel around the sock. I have not seen eveidence one way ior the other about blocking, I will look for some now.