Access to wood shavings, from a workshop...

I have access to an enormous volume of wood shavings and chips from a couple of workshops, one I work in and another nearby. Both create volumes and volumes of waste from their machining timber, more than I would probably be able to house, which would be a great problem to have.

The downside would be other materials in the waste - namely MDF and Plywood dust / shavings from these materials being cut. Its been estimated that it makes up a tiny portion of the waste - circa 5% or less, but nonetheless its there. Everything else would be hardwood (including some tropical here and there, but mainly ash, oak, beech, maple) or soft (a small amount of pines).

Given how nasty the sheet goods are though, before I get over excited, how concerned would you be about taking on that material, making up 5% or thereabouts of a pile? Would it degrade over time, swamped out by the wood chips and shavings? Would it be more contaminated that say, metal traces or alike in poor soils? I genuinely have no idea so turning to the wider expertise!

Much appreciated.

What are your plans for all of those wood shavings?

In general it would obviously be preferable to get the pure wood shavings so if you could collect at certain times when you knew none of the other icky stuff was in there that would be the easiest solution. If not, my experience with plywood tells me that the adhesives that hold it together certainly breakdown when exposed to the elements and quite quickly when exposed to soil conditions, but of course what they break down into is above my pay grade.
If the wood products were going to be used in a composting toilet, spread around an area of woody perennials, or used to make biochar I wouldn't be worried personally and would just try to minimize the contaminants in the loads I took.
If it was destined for compost for annual food plants, mushroom growing medium, or some sort of fresh mulch I would be much more cautious.
I suppose it also depends on your soil conditions. Are you growing in urban/suburban soil that is likely semi contaminated by heavy metals already? Or are you working with otherwise fairly pure rural soil? I'd be much more cautious about importing contaminants to a clean garden then adding a slightly contaminated resource to fairly contaminated soil

s. lowe wrote:What are your plans for all of those wood shavings?

In general it would obviously be preferable to get the pure wood shavings so if you could collect at certain times when you knew none of the other icky stuff was in there that would be the easiest solution. If not, my experience with plywood tells me that the adhesives that hold it together certainly breakdown when exposed to the elements and quite quickly when exposed to soil conditions, but of course what they break down into is above my pay grade.
If the wood products were going to be used in a composting toilet, spread around an area of woody perennials, or used to make biochar I wouldn't be worried personally and would just try to minimize the contaminants in the loads I took.
If it was destined for compost for annual food plants, mushroom growing medium, or some sort of fresh mulch I would be much more cautious.
I suppose it also depends on your soil conditions. Are you growing in urban/suburban soil that is likely semi contaminated by heavy metals already? Or are you working with otherwise fairly pure rural soil? I'd be much more cautious about importing contaminants to a clean garden then adding a slightly contaminated resource to fairly contaminated soil

Sorry, could have given some context. The soil here is clay, a little compacted and quite waterlogged in winter (a river runs on our boundary that floods this time of year). The site is rural and a former mill in the UK - apparently there is some potential contamination in the area, but I'm not sure it directly affects our land - there is a former foundry across the river from us.

I would love to take the materials clean, but alas the input of MDF / PLY cannot be controlled. It will absolutely be a small quantity - single cuts in each as opposed to shavings produced form bringing wood to size and dimension entails much more work and material being removed beyond the kerf of a cut. I would like to use it as mulch on circa 0/5 acres, for unwanted plant suppression before planting a new garden / forest garden. I could avoid it being used in an annual garden, but there would definitely be edible perennials planned in the rest of the space.

Personally I would use it. I already use a very similar source for the material I use as a cover material in my composting toilet. I have some (possibly unrealistic) idea that the long composting process will break down the plywood glues before it gets used in the gardens, etc. I don't think there would be heavy metals in plywood. Biomass and compost are in very short supply here so I'm happy to get whatever I can. I could be wrong though, and everyone has a different range of things they are comfortable with.

Rebecca Norman wrote:Personally I would use it. I already use a very similar source for the material I use as a cover material in my composting toilet. I have some (possibly unrealistic) idea that the long composting process will break down the plywood glues before it gets used in the gardens, etc. I don't think there would be heavy metals in plywood. Biomass and compost are in very short supply here so I'm happy to get whatever I can. I could be wrong though, and everyone has a different range of things they are comfortable with.

Thanks. Given one of the workshops is a workplace for me, I can assess the waste and where there is clear and obvious MDF dust / shavings, ignore those bags, generally speaking they use green MDF so its relatively easy to see if it went through the machines en masse. I can of course never be sure what exactly is in the bags, but I know the work that happens here at least and as such can be confident that 5% would probably be a maximum contamination and it would never be treated with paints or other finishes (maybe wax a couple of times a year) as far as I can tell - it is almost always hardwoods that are being processed. BUT 5% of compressed dust with glues and resins - is that akin to 5% 'paint' or other equally nefarious material that you would never want to touch your garden? Is 5% small enough not to matter or just enough to be a concern? Its a tough decision to weigh up.

I would (and have) gladly use cardboard as a weed suppressant before laying mulch or compost on top. To prepare cardboard I've removed tapes, staples and alike, but thinking about this - there is a good chance that some of the glue residue from the tape remains or areas where the cardboard has been stuck rather than taped, that glue would then be in the soil. I'm not suggesting that MDF formaldehyde based glues are akin to glues in tape, but its definitely a contamination. Whether that equates to this 5% figure I have pulled out of nowhere I don't know, but would be interested to hear thoughts on this point - at what point is the % low enough?

I cannot make a clear assessment, online research does suggest some test by local councils on composting MDF and similar materials, but it generally is all or nothing - they are considering the substance in bulk, rather than as a composite part. I've read a report that suggests adding 10% MDF amendment to a broader compost, actually produced a benefit (although not clear on what that benefit was) for resale as horticultural or agricultural purposes. Of course if this was 'all' MDF waste I wouldn't touch it, but as mentioned above our waste is in clear plastic bags so can be seen before collection and almost always would be wood.

research webpage