Afuel ladder orladder fuel is afirefighting term for live or deadvegetation that allows afire to climb up from thelandscape orforest floor into the treecanopy.[1][2] Common ladder fuels include tallgrasses,shrubs, and treebranches, living and dead. The removal of fuel ladders is part ofdefensible space 'firescaping' practices.
Potential fuel ladders should be removed to reduce the risk of fire bridging the gap to the canopy. To remove the ladder requirespruning any low limbs up to a minimum of 2.5 m (8 ft), and potentially as high as 5 m (16 ft). The required height depends on how low the branch tips hang, the steepness of slope, and the height and spacing of other nearby vegetation.[citation needed]
The desired result is to create a situation in which a low-burning fire could burn to thetrunk of a tree, which is protected by itsbark, without having thinner, more flammable branches,leaves orneedles within easy reach of the fire.[citation needed]
Apart from tree limbs, anything that would help that fire move up into the tree canopy is a fuel ladder. This includes shrubs and even tall grass or weeds. Non-vegetation fuel sources such as woodpiles, wooden fenceposts and structures should also be considered.[citation needed]
The intent is to maintain a break in vertical and horizontal continuity so that, if for example a woodpile caught fire, it would not be positioned next to shrubs or directly under trees that could then easily catch fire.[citation needed]
