Wooden blocks are blocks that are first introduced in level 3 of Powerup.
Wooden blocks look like light brown wooden crates. Each of the blocks consist of four trapezoid planks on its outside and six rectangular planks on its inside; blocks may occasionally have seven planks on its inside. Some blocks have a "heavy load" sign; others are also slightly darker shades of brown than others.
Wooden blocks appear frequently throughout the game in a variety of shapes and sizes--some with words scrawled across them, indicating a "heavy load" or something similar. However, words do not affect the gameplay or attributes of the blocks. Unlike metal blocks, wooden blocks are a non-conductive piece which cannot be used to create the actual circuit the player is required to do in each level.
These shapes, however, can be useful to support tall structures or, if cannons are present, to prevent a structure from toppling over. Later, in level eight, honey covered crates were introduced to the game, which were a variation of wooden blocks that could stick to walls and other pieces as well.