On Sloth

Excavated hole for IBC heat battery

The hole after initial excavation.

It may seem odd to start a story on the perils of sloth with the digging of a hole. Still, when my wife and I decided to bury two IBCs to be filled with water in the greenhouse for passive, and possibly active, heat storage then a hole was in order. Measuring over 8′ x 4′ and roughly 4′ deep, it was a fair task in the clay — though my proficiency with a mattock and shovel is pretty decent and I find digging to be a bit of a meditation.

The bit of laziness relates to a hose that had been used a little earlier in the year to drain the garage water collection system in preparation for the winter. It was connected to the outflow and run to the pond. After the system was drained, the end on the garage was disconnected and thrown on top of the coil near the pond and there it was left. For weeks, every time I passed it I thought “I should really coil that up and put it in the shed” .. and then I’d walk on by. When the first snow started falling I thought “really, I should get that put away” but it didn’t happen. And so our longest length of good hose ended up encased in ice.

Back to the hole. With the hole dug, insulating foam put in and taped up and one empty IBC in place, I filled in around one side of the foam with dirt. This was partly to keep it all in place but also to reduce some of the inconvenient mounds of clay I’d built up inside the greenhouse. I knew that the bottom foam was right at the top of the current underground water level and that the level could rise. I knew the correct thing to do would be to half-fill that one IBC to give it some heft. The hose I would use to run water to the tank, though, was encased in ice outside. At this point I should have either made efforts to extract the hose, chained some other hoses we have, run buckets to fill the tank or even just pull a bunch of concrete blocks from a stack I have to keep the whole thing weighed down. I’d like to say I evaluated the stability of the assembly and judged the dirt around the outside to be sufficient to keep it in place but the truth is I didn’t really contemplate it at all.

The flooded hole

The hole for the IBC Heat Battery after it was flooded. The IBC and foam have been removed, some wood added to save the garage foundation.

Worse still, I knew a big thaw was on the way. In fact, because I would be visiting the inlaws, instructions were left for the people tending to the chickens in our absence that when the thaw came they should grab the hose and throw it in the outbuilding so that it wouldn’t re-freeze in place. Those following along at home can probably already predict what happened when an empty IBC was left in a hole surrounded by slick pieces of foam with a rising water level. Upon returning home, I discovered the IBC floating on the lower piece of foam on several feet of water in my hole. While the outside of the original hole was stable, all of the backfill I had added had slumped into the hole. Making matters worse, some of the soil towards the garage foundation had started to slump as well.

For those not fully cognizant of how big a problem that last bit is, allow me to explain. Foundations are built on undisturbed soil. That is to say that the soil has already been compacted over a long time and so won’t further settle under the weight of the structure. If you dig your hole too deep for your foundation, you can’t just fill it back up with soil because that soil will be uncompacted and will settle further after you pour your footings. The result can be broken footings, a broken foundation and a broken structure. The same is true if you excavate underneath a foundation. The resulting void can’t just be filled back in and in fact there are companies that specialize in underpinning compromised foundations with concrete pours. As of our return, the soil hadn’t slumped from under the foundation but it was getting dangerously close. A failure here would mean a huge amount of work, much of which would probably have to wait until summer when temperatures for pouring concrete were high enough but after the high water levels of spring had receded.

I immediately screwed a board in place to keep all of the clay towards the garage in place as best as I could. I then set about pumping out all of the water using a small jockey pump. I tried a couple of larger pumps I had but a variety of issues kept any of them from working and I managed to clog up one large pump with clay — it really isn’t meant to handle debris. So the small pump it was, over the course of a couple days dodging the freezing temperatures outside of the greenhouse and taking great pains to keep the flow of water headed away from the garage.

IBC heat battery back together

The IBCs in place and half-full of water to keep them in place.

After the hole was somewhat drained, it was a matter of shovelling out all of the slumped clay. We have heavy clay in our area but the weight of straight clay is nothing close to the weight of that clay once it has been saturated by water. It is heavy, runny and sticky. In a few hours, though, I managed to get it all out of there and back down to the undisturbed soil, still under several inches of water. At this point I was able to float the piece of foam for the bottom, place the IBCs on top, surround them with more rigid foam and fill them half-way with water using our now recovered hose. After that, backfilling with clay was possible and our garage foundation, the greenhouse foundation and our overall timetable to get vegetables planted in early spring are now no longer in jeopardy.

Now imagine back to when I had drained the garage water system or that first snowfall or any time before the ice took over. Had I merely coiled that hose and tossed it in the shed or outbuilding, I could have filled that first IBC when it was in place. That would have kept everything stable and I could have sunk the second IBC later — even into a pit full of water — because the foam and clay would still be in place. I would have been the better part of a week ago where I am now and wouldn’t have risked setting us back by months and adding unknown expense to the project. An important lesson learned, I’d say.

Leave a Reply

Your email address will not be published. Required fields are marked *