Mold on covered wood - why? (Pics attached)

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New Member
Apr 15, 2023
Hello all!

Wondering if someone can help me out...

I built a small temporary woodshed, made up of pallets & some roofing felt. Water's not getting in so it's fine (will redo this over the summer). However, I seem to be getting mould on some of the wood, it's a greeny/blue colour. It's all kiln dried beech.

The mould is on the pieces lying flat, high up the pile. The upright wood is just because of no room and the lads laid out horizontally at the front is to soak in the water from the pallets (poor planning, no DPM under the pallets).

So my questions...

1) Is it safe to burn?
2) What is it & why is this happening?
3) How do I prevent this from happening?

Thanks & Merry Christmas!

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Kiln dried? What does that cost ? Do you have your own gas well ? If so , you don’t need to burn wood.
Hard to say for sure, it could have been kiln dried but not fully dried on the inside. Maybe not enough airflow getting to your wood shed along with damp environment causing just the right conditions for mold growth? Have you checked moisture content of a fresh split piece of wood?
I have recently learned, once kiln dried, wood needs to be kept super dry or it will mold. Possibly just the moisture in the air has caused mold on the exposed ends.

I'd burn it, in a good hot fire.
If you were closer I'd tell you not to burn it and drop it off at my house. I'll guess it's some moisture or mold spores, fire kills everything BURN IT.
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If I didn't burn moldy wood, we'd never have a fire!

Ireland? Is it as wet as the north west of France? This year has been soaking wet here in the Mayenne

my wood store does not have enough airflow and wet travels beneath it
Looking at the coloration of the wood faces I don't know if all of them are evenly dried? From my own woodstack these colorations are usually where the steam / few drops of water tends to collect after being loaded into stove.

Mold on covered wood - why? (Pics attached)
I get that sometimes on the second or third row in in my woodshed. I assume it’s from not enough airflow.

But yeah it reminds of the discoloration you sometimes get on dry lumber when it’s left in a damp environment.