The presence of moisture in pallet lumber can cause problems for both pallet and load quality. For certain products and pakages such as corrugated boxes, as weel as bagged or canned goods, for example the pallets should be dry to avoid any transfer of moisture which could result in packaging descomposition, rust, mould, mildew, or pest infestation.

The moisture content of a pallet corresponds to the weight of moisture contained in it, as expressed by a percentage of its oven dry wood weight. the rate of reference humidity is 20%. It confronts a humidimètre. This device consisted of 2 index cards and a probe measures the specific conductivity of the wood; then converts it in percentage of humidity.

ex : block pallets:
PM: Pallets moisture
TDM: Top decks moisture
SM: Stringers moisture
PSM: Pallet skids moisture
BM: Block moisture(wooden massive only).
PM = (TDH+SH+PSH+BH)/5

If one wants to be more precise it is advisable to admit the level-headedness due to the volume ( average arithmetic):
HP= ((TDM*TDV)+(SM*SV)+(PSM*PSV)+(BH*BV))/TV
TDV: Top decks volume
SV: Stringers volume
PSV: Pallet skids volume
BV: Blocks volume
TV: total wood volume of the pallet (TDV+SV+PSV+BV)

To note: do not take into account the agglomerated blocks, either for the moisture content, or for the global volume.

The moisture of a lot bases on sampling.

Pallets can be dried outdoors or artificially. One so distinguishes the wood dried outdoors (moisture content lower than 20 %) and the wood dried artificially which can go down until 16 %.


The wood is called: - dry wood (rate of moisture content maximum 18 %) - dry wood in the touch (rate of moisture content 22 %).

There are several qualities of dry palettes:

- dryness 18% % (that is from 16 % to 18 %). The palette remains dry even if it is placed in a wet environment, indeed, it does not resume the moisture content.

- dryness (in 22 %). Placed in a wet environment, the palette takes the moisture content outside but remains dry inside.

The green wood can be dry outside but wet rest inside. The moisture content of green wood exceed the 30 %. Naturally one does not use it to make palettes.