Ash planks

Boards of ash, a tough, springy timber that absorbs shocks well. Ash was valued for tool handles, spear shafts and cart parts. In the twelfth century most boards were split (riven) from logs and trimmed with axe and adze; sawing timber into boards spread only from the end of the century. Ash rots readily outdoors, so it was used mainly where strength mattered more than durability.

Sources: buildingconservation.com