'''Note:''' You must have at least one [[shaft]] in your inventory.
=== Skill Required ===
To calculate the maximum slope you can build on based on your [[carpentry]] skill, use the following formula (submitted by ketza):
''Max slope = (3 *'' √''skill) + 10''
'''Note:''' Round down to find the maximum slope.
Skill - Slope max
1 - 13 36 - 28
4 - 16 49 - 31
9 - 19 64 - 34
16 - 22 81 - 37
25 - 25 94 - 39
=== Tools Required ===