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It is safe to use treated lumber to build a compost box? Answered

I would like to build a compost box but I want this box to withstand termites, carpenter ants, rotting and weather. I am thinking about using treated lumber but I worry about preserving chemicals leaking to the compost pile and effecting the decomposition process of composting.



Best Answer 10 years ago

Yes, treated lumber leaches over time, especially when it is damp. I'd bet a buck it's going to hinder the process. Besides... if you build it, they will come. (The ants and termites, I mean.) Pests are part of nature's process. Although you and I might wrinkle our noses to think of creepy crawlies wrecking our hard work, they do contribute to the process of decomposition. With that in mind, I tend to build my stacks out of pest-friendly materials, especially if I can find 'em for free. God bless the discard pile, eh? In any case; even if you use treated lumber, any degradable substance stuffed with decomposing material will rot eventually. You might get an extra year out of it, sure-- but why shell out the extra cash for a product which doesn't contribute to the composting process?


2 years ago

Who's to say the pallet you're recycling wood from wasn't exposed to toxins of some sort? It would also pay to check out the actual stats and figures regarding toxicity. For example, I had a conversation with a guy -- and I know I'm not quoting actual facts at this point... I'm too lazy to google -- who said you'd have to eat a teaspoon of sand directly next to CCA treated telephone pole or sandbox frame, for over a year, to even come close to toxic levels. He showed me the report it was in. He was in construction and had to have an evaluation of an old site done.

Anecdotal evidence. For what it's worth. :)


10 years ago

Treated timber comes in many sorts and unless you are sure it is not with CCA treatment (copper chromate arsenate) yes that is arsenic then stick to the old pallets method.


Answer 6 years ago

It hasn't been legal to sell CCA treated lumber in the USA for residential purposes since 2003. It is highly unlikely you would find CCA treated lumber in a local lumber yard. If available at all, it would be only through industrial supply sources.


9 years ago

     The chemical's they use to treat lumber are carcinogenic, and not can, but do cause cancer.  It would be better to just avoid it all together for anything related to your food. (Vegetable garden.)
     I would use a plastic garbage can if i wasn't already given a commercial one as a gift. Or make one out of chicken wire, but that doesn't hot compost so it's slower and doesn't kill weed seeds. There are TONS of guides on here. :)
    If you are bent on using wood, redwood is expensive, and will rot after several years, but it looks nice, and termites won't eat it.


10 years ago

You shouldn't build a composter out of anything you wouldn't want to build, say, raised beds out of. Therefore, painted lumber, (unless it's nontoxic genuine milk paint), pressure-treated lumber, and composites are out. They will leach into your compost the same chemicals you wouldn't want leaching into your garden. Sadly, vinyl also leaches and is one of the WORST choices environmentally speaking. So, discarded wooden pallets are a great resource, or you can make a compost pile with just chicken wire around it, if you make it big enough it will heat up on its own. I went ahead and got a Biostack, and it has worked well for me for a modest price, but if I had been rural instead of urban, I would have used wood pallets secured together, or just a chicken wire circular compost "cage". Good luck!


10 years ago

Your compost will be full of creepy crawlies, composting = bacteria = creepy crawlies you can't see.
Like dutchy said, there's PLENTY of waste material lying around everywhere that you could build an equally decent compost box out of, without polluting your compost or opening your wallet.

If ants and termites are eating your compost box, think of how well members of your ecosystem who thrive on those creatures will do.