What concrete blocks for compost heap?

[DuncanM]

I was thinking something of a similar design to this, with some differences:
- Only 2 bays
- No concrete floor slab, just a supporting foundation under the block work only.
- shorter length bays


All the blocks are certified for use below the DPC and in foundations, so even though I get your point that isit's not the same as being part of a roofed building, I'd still expect them to outlast wood.

Thanks for the thoughts everyone.

[Bill HH]

That looks very neat, but i think they have used mortar.They have also filled in any holes at the top.
Leaving them loose would also be a magnet for any passing children to push them over. It might be worth using a concrete pad like that also as it would make forking the compost so much easier.

[DuncanM]

Yeah mortaring them looks to be the way to go, but as for passing kids I'm not sure that'd be a problem anyway given its at the back of my plot and will be bordered on 3 sides by a shed, an old wire fence and eventually, a polytunnel I inherited.

[Guest]

That does look very neat. However, for better compost is it not meant to be in contact with soil? and air allowed in all the way round? (I suppose this last bit depends on how much there is)

[DuncanM]

That's one of the changes in mentioned I'd make, no concrete slab so the heap will be in contact with the soil. I haven't fully decided if I'll build in small air gaps into the brick work yet, something to consider for sure

[Kristen]

I like the look of that but:

Are you planning to "turn" the compost at all?

If so I think 3 bays is better [than the 2-only that you are planning] and I saw on an award winning allotment holder's video, or blog (sorry, I've lost the link), that he rather ingeniously (or so I thought!) has 3 bins of unequal size. He fills bin 1, when it is full he emptied bin 3, turns bin 2 into bin 3, and bin 1 into bin 2.

Bin 3 is the smallest and designed, presumably with the benefit of experience, to be judged as the size that Bin 2 will have shrunk to during its composting period.

Not quite sure how turning Bin 1 into Bin 2 works, if bin 2 is smaller!!, but I suspect he fills bin 1 and then the next time he has a load to compost he first empties and turns them, but which time presumably Bin 1 has shrunk down somewhat. If not the least composted material, on the top, could be set aside as the "starter" material to go back in the bottom of the newly restarted Bin 1.

[veggiechicken]

Do your allotment rules allow you to construct a permanent structure out of block and cement?

[Potstubsdustbins]

I suspect the person who built those bins may just be a brickie in his spare time.

The joints are all uniform and the bonding is spot on.

[Olorin2001]

Take a look at this material.

EcoSheet l Recycled Plastic Board

[DuncanM]

I've ran it past the allotment committee and got the green light, including a small bit of praise for making something permanent as they actually appreciated it. As for neatness of laying the blocks 1) I don't care, it's a compost heap 2) I can lay them pretty straight anyway, it's not difficult. As for 2 bays, I'm tempted to put some recesses - or an extra block sticking out, allowing me to half each bay, making 4 with temporary sheeting if I ever wish, or left to be 2 large bays. I don't plan on turning, the majority of the material that will go in there will be manure, which I've left un-turned previously with great results.

Thanks to those who offered advice