Many people use chicken wire and rabbit fencing for their enclosures, so the fine mesh of hardware cloth will be more than adequate. You will need some beefy support on the bottom below the hardware cloth to prevent deformation from the weight of the compost, some type of rugged metal grid would be ideal. You should be able to fabricate something inexpensive out of rebar if you can't find a suitable material to recycle.

You should do just fine with the 1/2 inch mesh. Half-inch mesh is still pretty small, and most of my impromptu round bins are all about that size. The one from gardeners supply has weave that's bigger, with mesh probably about an inch horizontally and 1.5 inches vertically. A few small things fall out and have to be put back on top, but once the pile starts to settle things tend to stay put.

Is there a reason that you are going to limit the pile to a 3.2 foot diameter?

Our bigger diameter cylinders have the best success, both from the composting standpoint and for stability! Our biggest one is about 8 feet in diameter and six feet tall.

For the big piles, to help air reach the center of the pile we use a big PVC pipe with holes drilled in it stuck in as we are building the pile. We use them horizontally and vertically. (I don't like to turn the big compost piles, particularly if they're built to rot a huge stump.)

Here's a video where someone is talking about it--mainly so you can see the idea. I don't have sound here on the school computer so I don't know what they are saying--so sorry if they say anything incorrect! (Just look at the pipe!) :)

I can't speak to the mouse/vole/rat issue--I haven't had too much experience with them. The rare times I've encountered mice around compost I've just set snap traps for them. (No rats or voles yet.)

Here is a link that might be useful: Perforated PVC pipe for compost pile aeration

Perhaps you went to a big box store where they want to sell you a roll rather than cut it for you. Branneky on the Rock Road, St. Louis County is one of the good smaller stores who offers excellent service. They are one block from Home Depot so they have to offer good service as well as items not sold by the big boxes. I have no interest in the store or True Value, except as a customer.

I too am interested why the choice of 3.2 foot diameter. That would be good choice is sawdust is a main ingredient in the piles you plan to construct. If leaves and or wood chips will be a major ingredient, than 4 or 5 foot might be best. The larger the size of the carbon rich ingredients, the faster the air movement, so the larger the bin.

I've had no problem with a 8' diameter wire crib, 2" X 4" mesh fence. What little falls to the ground is easily scooped and thrown back in. I do that maybe twice a year.
hortster

{{gwi:264860}}

I'm using concrete reinforcing mesh (remesh) with openings about 4x4 inches. Yes, things do fall out, but I just rake them up and toss them back on the top.

The bins are about 3.5 feet in diameter, and 4 or 5 feet tall.

Thanks Robertz6 and Ralleia. I want to go with a 3 to 4 foot diameter cylinder because I read in "Let It Rot" that air doesn't diffuse into a compost pile much further than about 1.5 to 2 feet. So a radius of 2 feet will give a diameter of 4 feet for a 4-foot wide cyclinder.

But the author didn't qualify his general 3- to 4-foot recommendation with information about the specific sizes of the particles (whether they be tiny sawdust or big leaves), so I can see your point Robertz6. The bigger particles like leaves will have larger air spaces between the leaves than something like sawdust will have. What's the biggest diameter cylinder you've made without using a PVC air pipe like Ralleia uses for her 8-foot cylinder?

Maybe next time if I use an air pipe, I'll make a larger cylinder.

Wow, horster, love the photo! Since your circle-shaped pen has an 8-foot diameter, the circle's circumference (or length of the mesh fence you used) must be about 25.1 feet.

Without an air pipe in that behemoth, I guess it will take longer to decompose. Are you worried about it going anaerobic? Do you have any plans to aerate it with a pitchfork, or do you just prefer the long one to two year decomposition time frame

By the way, here's a quick geometry lesson for any newcomers who might not know this but who might be interested: No matter how small or large a circle is--whether it's 6 inches in diameter or a whole mile in diameter--whenever you divide the Circumference (or outside length, aka perimeter, of the circle) by its Diameter, you get the number 3.14.
(The diameter is the width through the center.)

3.14 is a constant in nature. Whenever you divide Circumference by Diameter of *any* size circle, you get 3.14. Hence, a constant.

3.14 is what "pi" ("pie") means.

So C / D = 3.14

Whenever someone says "pi," they just mean 3.14.

With this info, you can quickly figure out what length of fencing, chicken wire, or hardware cloth you need to make your compost pen, be it 3 feet wide or 8 feet wide.

By the way, the Area of a circle is calculated by multiplying 3.14 by the radius squared.
(The radius is half the length of the diameter.) To square the radius, just multiply the radius by itself. So a Diameter of 10 has a radius of 5. The radius squared is 5 times 5 or 25.

And the Volume of a cylinder is the Area of the circle times the cylinder's height.

So a cylinder with a diameter of 3 feet and a height of 4 feet will have a Volume of 28 cubic feet, which is just over a cubic yard (which is 27 cubic feet).

Hope this helps someone thinking about compost piles :-)

I used 2 X 2 wire mesh. It worked fine. It did dry out on the edges pretty quick so I used some cardboard to retain some moisture and it did "leak" once the material got decomposed a lot.

Lloyd

Whoa, my mathematical ZoysiaSod! We are actually talking about applying nitrogen, oxygen and water to carbon based materials!
By the way, when I picked my moniker for gardenweb, I never thought that the second "t" would be dropped so much, as it has been.
The bins I use were made from 1/2 of a 50' roll of what was labeled as, ironically, "horse fence" (whinnneeeyyyy!).
Also, when I do calcs referring to circles, I use 3.14159 which results in more accurate results.
Anyway, regardless of the volume, I stick the tube connected to my compressor into the pile for 15 seconds per jab. My back, vs. turning, appreciates the oxygenation and appreciates when the pile soon drops. Others might be surprised how this saves labor and accomplishes the same goal.
You are looking at 3 years of OM in the pile in the pic. However, my present needs are going to use up both of the piles you see - the old one on the left and the present one. Last spring I used the entire previous pile on the veggie garden. Going to be starting a new one in heavy clay so will need all the OM I can muster.
hortster

Regarding Hortsters' impressive bins, they are easy to turn if they are constructed to easily open up. This can be done with s-hooks, carabiners, or any number of other methods. The wire is removed and relocated, and the material is forked back in. This adds air and puts the drier material on the inside of the pile. The process of turning also adds some mechanical breakdown, making the brittle ingredients, both wet and dry, smaller and more digestible. This is an even better method than my pallet system if you are actively composting by turning the pile, but requires purchasing the wire, whereas pallets are free.

Hortster wrote:
> Anyway, regardless of the volume, I stick the tube connected to my compressor into the pile for 15 seconds per jab.

Hortster, that sure is a clever idea using a compressor to pump air into the pile. For the not-so-mechanically inclined among us, compressors are those things found at gasoline stations that you use to pump air into your car's tires. The air hose is connected to a compressor.

Compressors can be bought at Harbor Freight, Walmart, and other stores.

Air infiltration into your compost pile can be between 2 and 3 feet. Some years ago I had compost piles that were 6 feet by 6 feet by 45 to 60 feet and had no trouble with air infiltration. There should not be any need to use some method, air compressors or chimneys in any pile less then 6 feet wide. If the material is too wet air will not infiltrate deep enough, but that has nothing to do with the depth of the pile because water will dispace air.
I found, long ago, that hardware cloth needs much more support and is best utilized when tacked onto a wood frame which then takes the brunt of handling. The welded intersections of hardware cloth, in my experience, come apart too easily if handled without good support.
2 x 2 (tot lot fencing) or 2 x 4 mesh welded wire fence has worked very well for me for many years and is about 1/2 the cost of the hardware cloth.

Kimmsr, thank you very much for your reassurance about 6-foot wide piles. You and the book Let It Rot back each other up 100 percent:

"....a pile that's too large can have different problems. The length doesn't matter, but if you make it much wider or higher than 5 or 6 feet, the center of the pile may not get enough air and you could wind up with an anaerobic area there. Air naturally penetrates anywhere from 1.5 to 2 feet into a pile from all directions, but not much beyond that."

Not sure why Let It Rot uses a 1.5 to 2 foot radius which allows for a 3 to 4-foot diameter, but in the sentence just before that, says a 5 to 6 feet diameter. It seems a little contradictory, so I'll go with you Kimmsr.

About the hardware cloth needing much more support and is best utilized when tacked onto a wood frame, "Let It Rot" says:

"Bins made with [1/2 inch] hardware cloth should be strong enough to stand alone without posts."

However Let It Rot does say to use 3 or 4 wooden or metal posts to support 1-inch chicken wire.

I bet you're right, Kimmsr, that posts would be helpful even with 1/2-inch hardware cloth because "Let It Rot" kind of waivers by saying "should be strong enough to stand alone without posts."
The "should be" makes me wonder.

I think that whether it will stand alone is going to depend on:

* the ratio between height and diameter of the cylinder
* the levelness of the ground where you make your pile
* the winds that the area experiences

and also somewhat on the composition of your pile (light and airy versus moistened through and therefore moderately heavy).

Our big 6-foot tall, 8-foot diameter pile stood just fine by itself on level ground, even in high winds. But when we used it on the uneven terrain around the linden tree stump we had to stake it in three places to make it stable.

Chicken wire is of course going to need to be staked, because chicken wire is so cheap and flimsy it's hardly worth anything, even for containing chickens! And woe to the chicken keeper who thinks it will keep OUT any determined predator. Hardware cloth is a much stronger (and more expensive) product.

I would tend to think that if you keep the cylinder at least as squat as it is wide, hardware cloth will not have trouble standing on its own on level ground.

A few long pieces of rebar pounded into the ground are all the support you should need.

I have 5 bins made from 1/2" galvanized hardware cloth that are 4 ft. in diameter. These bins have held up very well and do not need to be supported with stakes/posts. My bins are placed on level ground.

Like the poster above said, you should not have a problem as long as the ground is relatively level.

I also have a few bins made from scrap concrete reinforcement wire (CRW) with 6x6" spaces. I would not recommend these as too much material falls out of these bins. I usually line the inside with cardboard to help with this problem.

Hi Hortster. I caught my misspelling of your name about 30 seconds after I clicked the post button. One time I spelled "odor" as "oder" and caught that a couple minutes after posting. ....the ones that get away...

Maybe even a regular leaf blower might work to pump air into a pile.

AutoZone and O'Reilly might have some inexpensive compressors for those looking.

Rokal, thanks very much for that great info about your 1/2-inch galvanized hardware cloth.

I spend a good bit of time trying to proofread my posts, and I always find a few things I missed. Most of us get the gist and let it slide, I think.

According to what I have found 2 x 4 vinyl coated welded wire fence fabric in 4 foot x 100 foot rolls is about $99.00 while 1/2 inch mesh galvanized hardware cloth in the same size is about $350.00.

Kimmsr wrote:
> ....1/2 inch mesh galvanized hardware cloth in the same size is about $350.00.

Kimmsr, that's not a good price. Here's a much better price :-)

A 4-foot-tall, 50-foot-long roll of 1/4-inch mesh galvanized hardware cloth on Amazon is $73, which includes free shipping. It's the best price I've found anywhere, except for the occasional seller on Craig's List.

Here's the link:

Amazon's 4x50-foot, 1/4-inch roll

I got mine through Craig's List from a great local farmer who had some new stock he had never used or opened. It was a quick 35-minute drive to his place in O'Fallon or Shiloh, Illinois, really close to SWIC. I'm in Missouri.

A 1/2-inch mesh roll is $13 more on Amazon for some reason.

A 100-foot roll of 1/2-inch mesh on Amazon is $155 to $177 which includes shipping:

4x100-foot roll of 1/2-inch mesh

I'm a cheap guy so I searched everywhere before buying the hardware cloth like:

Froogle.com

PriceGrabber.com

The Big Box stores

Ebay.com

Local hardware stores like Tru Value (did you know different local Tru Value stores sell at different prices. I guess each is individually franchised. Thanks for the Bennecky's Tru Value tip, Robertz6--Bennecky's Tru Value has better pricing than the Tru Value close to me.)

Amazon.com

and Craig's List

and maybe a couple other places I've forgotten.

You could also try to get some INOX wire mesh at www.wiremeshes.eu .They produce very strong wire mesh which can survive severe circumstances, way better than chicken wire. The durability of these type of woven wire mesh products is very high.

Here is a link that might be useful: Wire mesh

If someone covered this I missed it: I never use a floor in my wire mesh cylinders. It's not really necessary for the composting process, and it would make it darn near impossible to undo and remove the fencing from the pile in order to turn or use the compost. Just a plain cylinder is fine.