Offgridburbia

I had planned on starting installation of the french drain and rubble trench foundation today but unfortunately/fortunately it rained earlier in the week. According to my parents’ neighbor it was a real gully washer clocking around 4 inches. So, the formerly rock hard soil has gotten a little squishy, especially the lower end of the trench. On the fortunate side we’ve haven’t had any rain in a month and half. It also served as a test for my foundation drainage plan. It was pretty sloppy in the trench so I made some test blocks. Check out the results below.

Who needs a pick up truck when you have a hard working sub compact hatchback?

Of course passenger space becomes an issues as does transporting a board longer than 8 feet.

Close to the drain outlet but not quite. When it dries up some I’ll lower that hump to allow the water to drain off.

Fortunately, most of the water went to drainage outlet which is good.

After squishing around for about half an hour I hosed myself down and decided to build a block test form.

Form built and ready for mud.

18 minutes later mud has been packed in and the form removed. Looks like the block is holding tight. I was really surprised by how easy it was to remove the form.

The first block is on the left. My second attempt is on the right. The second attempt was made with a slight soupier mix along with some lime. I also did a better job tamping the corners and it turned out much better. Because the mix was more liquid I left it in the form for about 40 minutes.

Another important test is checking your building soil’s clay to sand ratio. To do this you partially filled a jar with your test soil and then fill it up to the top with water. Then you shake it up like a snow globe and set it aside for a few hours. The sand will settle to the bottom first, followed by silt and then finally clay. The split between the sand/silt and clay is pretty distinctive unless you’re looking at a blurry, poorly lit image with reflection. In an ideal world you want 20-25% clay in your mix. Our soil is about 33% clay. I might add a little decomposed granite or sand as we go along.