Will Sand Gravel Suffice For French Drain?

I'm having a hard time locating any other type of gravel but the sand gravel we have here, which consists of sand, gravel, and stones in every size up to 15cm (I believe it's bank gravel but not sure). If I were to make the trench deep enough to fill with additional gravel, would it suffice for something like a French Drain to divert water away from the house?

Is that the type that is used for making roads? As it sets down and compacts to make a good surface? To use it for drains you would need to take all the sand out, it will filter down between the stones and clog everything up.

I'm with Skandi on this one. Although the material you describe may drain moisture, the question is how fast? You always want to plan for the worst possible rain scenario in your area. Small rocks that leave plenty of room for moisture to travel quickly is what I would recommend.

you could pour it through a wire mesh to separate out the big rocks for the sandy small stuff. like hardware cloth, or even a smaller mesh if you have something like that...

leila hamaya wrote:you could pour it through a wire mesh to separate out the big rocks for the sandy small stuff. like hardware cloth, or even a smaller mesh if you have something like that...

I was thinking this exact thing.  I've got a couple of 2 x 3 foot screens that I use to sift my compost when I'm making potting soil.  The frames are made out of 2 x 2's, and the wire mesh is in two sizes: 1 inch and 1/4 inch.  The 1" catches the big stuff, while the quarter-inch screen only allows the fine stuff through.  Here's a company that makes them, although I made mine in about 5 minutes with some left over lumber, some screen, and a staple gun.

http://www.thesoilsifter.com/


If you're wanting to do a lot of soil, then build yourself a grizzly.  Google "rock grizzly" for images -- basically a big wall of screen that you can dump quantities of soil onto to sift out the big rocks.  In your case, you'd be sifting out the fine sand and keeping the larger aggregate.

Best of luck.
m

Maruf,

I have to agree with everyone else on this.  Sand would be bad.  Can you get rocks for the same purpose?

Eric

Marco Banks wrote:

leila hamaya wrote:you could pour it through a wire mesh to separate out the big rocks for the sandy small stuff. like hardware cloth, or even a smaller mesh if you have something like that...

I was thinking this exact thing.  I've got a couple of 2 x 3 foot screens that I use to sift my compost when I'm making potting soil.  The frames are made out of 2 x 2's, and the wire mesh is in two sizes: 1 inch and 1/4 inch.  The 1" catches the big stuff, while the quarter-inch screen only allows the fine stuff through.  Here's a company that makes them, although I made mine in about 5 minutes with some left over lumber, some screen, and a staple gun.

http://www.thesoilsifter.com/

If you're wanting to do a lot of soil, then build yourself a grizzly.  Google "rock grizzly" for images -- basically a big wall of screen that you can dump quantities of soil onto to sift out the big rocks.  In your case, you'd be sifting out the fine sand and keeping the larger aggregate.

Best of luck.
m

yep ditto. those are much prettier than my compost screens though, just stapled on hardware cloth over a frame.  very useful for many things, great for seperating roots out of soil...especially when you are digging up soil for new beds you can sift the soil through those to take out weedy roots and rocks.

put two pieces of hardware together and staple them onto something and then you have a finer mesh.

Thanks for the responses everyone, that's great to know, hench I'll look into a sieve contraption to filter the two. In that case I could use the smaller particles for the cob. Being in north-eastern Europe I don't have access to all the tools and stuff as in the states, so I'll look into making something similar to a rock grizzly here if at all possible.

Keep in mind that fast-running water can move even fist-sized rocks, and you don't want anything causing a blockage.

Is there anyplace you can get recycled road pavement or concrete, the highway department often has piles of road material they've busted up and replaced.  If you can get pieces that you can break down into smaller rock, it might be free or cheap.  

For an update, I ended up ordered rocks of various sizes and I created a double sieve system to backfill the french drain, with incrementally smaller rock sizes and sand as the final layer