Dustin Fife

Thanks again for the comments. I don't mind raising the foundation higher, but how does that fix the high water table problem? Also, it seems that a higher foundation would require rebar?

Thank you all for the excellent advice. It sounds like urbanite will work, if I do it right (namely, draining the foundation).

But now we have a new problem: The cabin location is probably only about 2-4 feet higher than the lowest point. It runs right next to a creek that drains into swampland only about 20 yards from the cabin site. Poor planning on my part. Needless to say, I don't think there's enough elevation to keep the foundation well-drained. What do ya'll think?

As an aside, a few days ago I decided against a log cabin and instead am doing a timber frame hay bail structure, so there's much less weight to support now.

Thoughts?

Thanks everyone for the thoughts. Let me clarify a bit. I am really trying to see if there's any problem with using urbanite and/or if there are other alternatives that are cost-effective and sustainable.

Some thoughts that I've considered (and sometimes dismissed):

1. Fill the holes with urbanite then stack boulders atop that. Alas, the boulders would be more expensive than the concrete, so no go (unless I find some boulders on craigslist or something).
2. Do a rubble trench foundation. Problem: the water table is too high to allow this to drain.
3. Use cedar logs on grade. I don't recall what the problem was with this one.
4. Similar to #3--stack urbanite inside the holes until they're just poking out (like a few inches), then stack the cedar logs on top of that.
5. Rather than bind the urbanite together with mortar, surround it with woven wire (or something similar) to prevent slipping. Then if water gets inside, it will freely drain out, rather than freezing and expanding.

Basically, I'm trying to avoid concrete because of the costs/effort/environmental impact. Any other out of the box ideas? Any comments on the ideas I just mentioned?

Hi all,

I'm in the process of building a log cabin tiny house in the woods adjacent to my home. I'm struggling quite a bit with the foundation at the moment. I began with the idea that I would build with urbanite (broken chunks of concrete), fastened with mortar (much like one would lay bricks with mortar). Someone said that was a bad idea (urbanite foundation at stackexchange) because water would penetrate the cracks between the urbanite, expand when frozen, and crack the concrete.

So I decided to put the urbanite chunks in the bottom of the hole (mixed with mortar), then make the top out of solid concrete. But now I have a new problem: The water table is quite high, higher than the frost line. I've been told by builders the issue itself is not a problem because concrete is routinely exposed to water. The greater issue is that if I do pour concrete, I need to extract the water to maintain proper mixing proportions. This is what I've been doing: extracting with a hand pump, pouring a load of concrete, waiting a few days, then repeating the process all over again. At this rate, I'll finish when I'm 192.

I'm trying my best to be environmentally conscious and cost-effective. To pour the foundation would cost about 1K. Not terrible, I supposed, but it's currently prohibitive. (The wife says I can't spend any of the family money on this cabin, so any money I do acquire would be bits at a time and in small amounts, until I land that movie star gig I've been auditioning for).

So, I have a couple of questions:

1. Is it really a bad idea to fasten urbanite with mortar? The logic makes sense (again, water penetrates, then expands when it freezes, thus cracking the foundation), but aren't homes routinely built from brick and/or stone and/or cinderblock foundations in exactly this way? What makes this situation any different?
2. Can I just backfill the holes I dug (9 in total) with urbanite, then set large stones on top of the urbanite? I'm thinking it would be way less money to buy 9 large stones than to pour concrete (and it's much more environmentally friendly!)
3. Any other cheap foundation ideas I'm missing? I'm in the northeast near Philly, so it gets pretty cold, but not massively so, if that makes a difference.

Good point.

I'm going for as low maintenance as possible with my rabbits. This is the first year I've had rabbits and I've heard horror stories about rabbits getting too hot and kicking the bucket before harvest time. So, as summer approaches, I'm trying to find ways to keep them cool so they don't croak. They're currently housed in a shed with an open window that sits below several shade trees. But, summers get into the upper 90s here. I'm not a fan of the idea of lugging gallons of frozen water every day or draining electricity with an air conditioner or fan.

So here's my idea: I was thinking I'd attach a currogated pvc drain pipe to the side of the shed and dig a trench underground with several forks in the pipe for mini burrows. I might even terminate the pipe with open dirt since bunnies don't seem interested in burrowing out of ground (just in). Then they can extend the burrows as they please. After laying the pipe, I'd backfill and the buns can move downward when things get too hot. When it's time for harvest (or other such maintenance), I can attach a one-way door to the burrow's opening.

Thoughts? I'm not engineer, but it seems like an effective solution (albeit labor intensive).

If opposed to the idea, any other low-maintenance ideas?

wayne fajkus wrote:Rye grass seed not an option? Where im at (texas), just scatter the seeds  and it's up a week later. Needs water Of course.

I like that idea. It's still in the 60s and 70s here (and will be for the next week), so that may work.

Marco Banks wrote:I'm guessing that furniture blankets wouldn't be organic --- some sort of polyester/non-biodegradable fabric.  If you could get a big box of cotton sweaters and stake them down, covered with a nice layer of mulch, that would all break down.  :>)  

They're actually recycled denim.

Marco Banks wrote:Finally, thinking about the cumulative weight of the moisture in the soil—this is where things might get hairy.  Saturated soil becomes tremendously heavy.  Once it starts to move, look out.  With no roots to keep it stable, a heavy rain storm will create a great deal of pressure as the soil becomes very saturated.  It's one thing for the slope to erode as water rushes down over the surface creating gullies.  It's quite another thing when you have a slope fail and tons of earth starts to move.  Get out of the way.

Yes, this is what I'm worried about. I started thinking that maybe I could plant some strawberries, rhubarb, asparagus, and daffodils now. I know these can be planted in my zone this late in the fall. I just don't know if the roots grow at all. Do you happen to know?

Marco Banks wrote:What is the angle of the slope --- have you measured it?  Perhaps there is a civil engineer reading this thread who could speak to the forces generated by heavy soil in relation to the degree of slope.  Obviously, the steeper the slope, the greater the danger.

Good question. I'm at work so I can't immediately answer. But these are fairly small berms; not more than two feet high and 2 feet wide.

Thanks for the replies, Bill and Marco.

A few comments.

Marco said: "I don't see the risk of a collapsing berm, as you put it, any less severe in spring than it would be in the fall.  Most places, you get heavy rains in spring just as you do in the fall --- perhaps even heavier."

Thanks for chiming in Marco. The issue that I'm concerned about is not more or less rain in fall versus spring. The issue is that I don't think roots will grow during the fall/winter to help stabilize the berm, no matter whether it's spring or fall. Sorry if my post wasn't clear on that.

Re: Mulch. Fortunately, I have lots of that. My yard is pretty much a leaf wasteland and I have 4 acres of mostly wooded property. Between dead branches and leaves, I have lots. I also have a wood chipper that I use frequently to make additional mulch.

I actually dug two trenches on contour. The one on the downside of the slope, I buried tree limbs in a pseudo-Hugelswale configuration then backfilled with dirt (kind of like Bill suggested). This morning I did as both of you said and heaped a bunch of mulch (cardboard, leaves, and wood chips). Given this, do you think it will now withstand any erosion issues?

Re: Erosion control fabric. Thanks for pointing me in that direction. Based on your suggestion, I was actually thinking about using my furniture blankets from moving. Any potential issues you see with that? Or would that be overkill (given that I've already heavily mulched the berm)?

Re: Where I live. Yeah, big oversight on my part not telling you that. I live in South Jersey, which is 7a. My property has a lot of Sweetgums, maples, and oaks, with the occasional cedar.

Thanks again for all the help!

Howdy!

First post here, so hopefully I'm not doing anything wrong here.

I just moved into a new home on four acres. About 2/3 of an acre is clear and I got all anxious and started digging swales. As I was about to plant some apple trees in the berms, I had a "wait a minute..." moment. I remembered reading somewhere that plants need to be planted immediately after heaping the berm to prevent erosion. But, since I'm planting in the fall, I don't expect the roots to expand all that much, and so I don't see how they'd help much with preventing a collapsing berm.

So, is a collapsing berm inevitable if it's heaped in the fall? Should I backfill and wait until spring to finish my berming?