concrete slab for compost

[Eric_Phillips]

My wife wants to compost her horse manure on concrete slabs. I have never poured a slab before, any tips? I was thinking of making the top level with the ground so I am not having to adjust the bucket when the wheels get to the slab. The bays I was going to make about a foot wider than the bucket. What about ground prep. It will be on sandy loam. Is 4" thick good and what about rebar?

 

[Treemonkey1000]

You will probably get an ear full of responses about concrete. Can you get some of the loam dug out to get to some more solid dirt as a base? I am no concrete expert. But I would think the fact that you are going to drive on it with the tractor and having the compost pile. You would want at least 4" with some rebar. Depending on how big of a slab you might want some relief cuts in the slab. Having a ramp onto the slab seems to make sense in my mind which means having the slab slightly above ground level. The run off from the compost will you have to worry about that much? Say if you get a large rain and it starts to float away the material and liquids.
Ahh I am just rambling here it seems. Let some other bright person chime in and give you some good advice. Get some friends to help you pour the slab. It really isn't hard if you have some forms built there. I had a ready mix truck drive up and mix the concrete on site and to the thickness I needed. It was a piece of (concrete) cake.

 

[bpattie]

I have been composting horse manure for years. I have never done anything as fancy as you are proposing, but I like your idea. I just pile it up and move the pile from time to time until I end up using it somewhere. You mentioned bays, is that is indicating you will have sides and a back? I have seen several designs that do include that to make it easier to turn over occasionally. Only thing I do know about composting is that adding air by turning from time to time speeds up and increases the effectiveness of composting.

 

[Eric_Phillips]

My wife has been the one looking into this. I am sure just putting it in a pile on the grounds works but she claims this is better. I was planning on putting a back and some sides. This way we can have the pile we are adding to, the cooking pile and the finished. With the back and sides it should help in turning and not pushing it around with the bucket. I don't think they need to be more than 4' high.

 

[Treemonkey1000]

I did a quick Bing Search for composting manure.
A Guide to Composting Horse Manure
There are plenty of links to the subject.

 

[bpattie]

good article TreeMonkey. Eric, no doubt the concrete bottom would be better than the dirt. I also like your 3 pile scenario. It is interesting how much heat these piles can build up. I know when I turn them in the WInter the inside when exposed produces steam. Also have found some on the inside that actually burned to ash. be careful where you locate the piles just as a precaution. My folks set a couple bags of grass clipping under their boat until trash day and one of the bags caught fire and set the boat cover on fire.

 

[charlz]

When composting grass, garden waste etc. I have used the '3 bin' method using bins made of old wooden pallets and turning by hand. When I get horse manure it's by the multi-dump trailer load and too big for bins. The best/fastest system I have found so far:

Dump the trailer loads end to end in a windrow.
Wet thoroughly (I have a 1.5" hose I use, makes quick work of wetting down).
Back into/over the pile with my 3pt tiller. I do this working down each long side to make sure things are thoroughly mixed/aerated.
Wet down again
Re-stack the now flattened windrow with the front end loader.
Repeat wetting/tilling/wetting/stacking 2-3 times every two weeks or so.
After about 2 months move it to the 'done' pile. At this time it is about 1/3 it's original size.

 

[bpattie]

Back into/over the pile with my 3pt tiller. I do this working down each long side to make sure things are thoroughly mixed/aerated.
Wet down again
Re-stack the now flattened windrow with the front end loader.
Repeat wetting/tilling/wetting/stacking 2-3 times every two weeks or so.
After about 2 months move it to the 'done' pile. At this time it is about 1/3 it's original size.

boy tilling is a great idea, not to practical for me, but great idea. that would really aerate it, which speeds up the composting.

 

[JC-jetro]

There is better dirt and composting material contact on the ground. Much of composting done by bacteria in soil. I always add a bit of dirt on the compost pile to increase bacterial activity. House keeping seems to be easier on concrete. On this Old House they showed a commercial composting out fit and basically all they were doing was to make piles turned over by a loader, they sweetened the mix by adding water and dirt... that's all.

JC,


By the way, I don't use the pitch fork to turn the compost and instead use my front tine 5.5 hp tiller and work it up like that. works like a charm.

 

[charlz]

boy tilling is a great idea, not to practical for me, but great idea. that would really aerate it, which speeds up the composting.

Not only does a great job of getting it aerated but mixes the moisture evenly through as well which really helps. Generally I always seem to have a problem keeping compost piles wet enough.

 

[lhfarm]

Did you see this post Heat your home with grass clippings! - TractorByNet.com ? Maybe throw some pipes in the slab for a future project.

 

[ToadHill]

I'd go with 6" and rebar. Put gravel under the slab and around to drain off any moisture or you'll have a messier area than you think. The idea of some pipe under the slab is worth a look.

 

[studor]

I would build the slab level with the ground at the access side and slightly sloped up from the center to the sides for some drainage -- make it 6" with rebar or chopped fiberglass. I would get it ready(dug and formed) then phone the redi mix supplier and see if you can get a part load when they are going nearby ( cheaper). Make the "stalls" at least 2 feet wider than than bucket and make sure it is in a location where the prevailing wind blows the odour away -- JMHO

 

[bpattie]

just to add a thought but when you pour the concrete you may want to set something to support your upright posts if you are not going outside the slab for them. I wold set them on the concrete and with those 4X4 post brackets you could always replace the posts if needed using the same bracket.

 

[Eric_Phillips]

Thanks for all the input. Please keep it coming if you have more. I am not sure if I will get to this before winter or not. The wife has been in charge of getting the info needed but maybe I should take a look at some of the links supplied here just to make sure she is still on track. What size rock should I use under the slab for drainage?

To respond to a couple of posts. I like the idea of getting a truck in but I don't have good access for large trucks anymore. I think I will just have to bite the bullet and rent a portable mixer and try to bang it out with that. My volume is coming from one horse and one pony not by the dump truck load. She is filling one muck bucket a day. I was thinking of pounding some posts in just outside of the slab for the back and sides. Now after thinking a bit using some plates on the slab sure would make life easier when the posts rot out. I was also thinking of using PT wood to make the back and sides. Now thinking about the bacteria needed to compost well that might not be a good idea.

Thanks,
Eric

 

[bpattie]

just my opinion but think PT wood would be ok. Some that I have seen also leave a gap in the boards. nothing that large but a gap. I guess it lets the pile breath a little.

 

[ToadHill]

For rock under the slab I'd just use crusher run.

 

[Iowachild]

At the bottom of this page is the best plan I have seen for a 3 bin compost system.
Compost Bin Construction Plans

 

[studor]

My composter is made out of PT and it has never stopped things from composting. If you have to mix the concrete by hand, maybe you want to use limestone screenings and old interlock instead? Leave gaps in the side boards and use wire if you use big gaps My composter is made with posts in the ground with stalls made from old deck boards. My old tractor had a narrower bucket than the current one hence the build wider thought. I just packed sand as a base although the concrete sounds nice but with the bucket on float I have never really had a problem. Make sure the back is strong so you can push the pile against it with the bucket to turn it. I moisten the pile regularly and my friends do as well if they have been drinking my beer

 

[theboman]

I want to make one for leaves etc, hopefully I'll have some scrap 1X from the Iron Hill Shed Project to make one, otherwise I'll just get me some pallets. We got a whole heap of leafs...