| Width | Wide enough for the whole body |
| Technique | Counter-pressure on both walls |
| Wider than | An offwidth |
| Difficulty | Intermediate |
A chimney is a crack or gap in the rock wide enough to fit your whole body inside. Climbers ascend it by pressing against the opposing walls with their back, feet, hands, and knees — a technique called chimneying — rather than gripping holds. Chimneys are awkward and strenuous but can offer secure, restful positions.
How you climb one
Brace your back against one wall and feet against the other so counter-pressure holds you, then walk upward — closely related to stemming in a wide corner.
Chimney vs offwidth
Narrower than a chimney but too wide to jam is an offwidth. See chimney vs offwidth.
Frequently asked questions
What is a chimney in climbing?
A chimney is a gap or wide crack big enough to climb inside, with your whole body between two facing walls. Instead of holds, you use counter-pressure — pressing your back against one wall and feet against the other — to move up.
How do you climb a chimney?
By chimneying: brace your back and feet (or hands and feet) against the opposing walls so friction and pressure hold you, then 'walk' upward by alternately moving your back and feet. Wider chimneys need more committing technique; narrower ones blend into offwidth climbing.
What's the difference between a chimney and an offwidth?
A chimney is wide enough to fit your whole body inside and climb with full-body counter-pressure; an offwidth is narrower — too wide to hand-jam but too tight to get fully inside — making it more awkward and strenuous than a chimney.
Sources
- Wide crack technique — American Alpine Club