Climbing wall

Types

The simplest type of wall is of plywood construction, known colloquially in the climbing community as a 'woody', with a combination of either bolt-on holds or screw-on holds. Bolt-on holds are fixed to a wall with bolts that are inserted through the hold, which will have specific bolt points, and then fixed into pre-allocated screw-threaded holes in the wall. Screw-on holds are, by contrast, usually much smaller, owing to the nature of their fixing. These holds are connected to the wall by screws, which may be fastened anywhere on the wall's surface.

Some other types of walls include slabs of granite, concrete sprayed onto a wire mesh, pre-made fiberglass panels, large trees, manufactured steel and aluminum panels, textured fiberglass walls, and inflatables. A newer innovation is the rotating climbing wall: a mechanical, mobile wall that rotates like a treadmill to match your climbing rate of ascent.

The most common construction method involves bolting resin hand and foot holds onto wooden boards. The boards can be of varying height & steepness (from completely horizontal 'roofs' to near-vertical 'slabs') with a mixture of holds attached. These can vary from very small 'crimps', and 'pinches', and slanted-surfaced 'slopers', to 'jugs', which are often large and easy to hold. This variety, coupled with the ability for the climbs to be changed by moving the holds to new positions on the wall, has resulted in indoor climbing becoming a very popular sport.

Spray wall

A spray wall is an overhanging climbing wall almost fully covered by a great variety of different sizes and shapes of climbing holds, in apparent chaotic distribution. It is used to train power, endurance and routesetting.

Equipment

Proper climbing equipment must be used during indoor climbing. Most climbing gyms lend harnesses, ropes and belay devices. Some also lend climbing shoes and chalk bags. Some climbing gyms require use of chalk balls (as opposed to loose chalk) to reduce chalk dust in the air and chalk spills when a chalk bag is tipped over or stepped on. Reducing chalk in the air helps to avoid clogging ventilation systems and reduces the dust that accumulates on less-than-vertical surfaces.

Indoor climbing

Indoor climbing is an increasingly popular form of rock climbing performed on artificial structures that attempt to mimic the experience of outdoor rock. The first indoor climbing gym in North America, Vertical World in Seattle, was established in 1987. The first indoor climbing hall in the world was inaugurated in Brussels, Belgium on May 16, 1987, by Isabelle Dorsimond and Marc Bott. Terres Neuves integrated the concept of pre-drilled plywood walls fitted with T-nuts, as developed in 1986 by the Brussels-based firm Alpi'In. Pierre d'Haenens is the inventor of this system, which is now used worldwide by all climbing wall manufacturers. Terres Neuves still exists today in an almost unchanged form.

The first indoor walls tended to be made primarily of brick, which limited the steepness of the wall and variety of the hand holds. More recently, indoor climbing terrain is constructed of plywood over a metal frame, with bolted-on plastic hand and footholds, and sometimes spray-coated with texture to simulate a rock face.

Most climbing competitions are held in climbing gyms, making them a part of indoor climbing.

Compared to outdoor climbing

Indoor and outdoor climbing can differ in techniques, style, and equipment. Climbing artificial walls, especially indoors, is much safer because anchor points and holds are able to be more firmly fixed, and environmental conditions can be controlled. During indoor climbing, holds are easily visible in contrast with natural walls where finding a good hold or foothold may be a challenge. Climbers on artificial walls are somewhat restricted to the holds prepared by the route setter, whereas on natural walls they can use every slope or crack in the surface of the wall. Some typical rock formations can be difficult to emulate on climbing walls.

Routes and grading

Holds come in different colours, those of the same colour often being used to denote a route, allowing routes of different difficulty levels to be overlaid on one another. Coloured tape placed under climbing holds is another way that is often used to mark different climbing routes. In attempting a given route, a climber is only allowed to use grips of the designated colour as handholds, but is usually allowed to use both handholds and footholds of the designated colour and surface structures and textures of the "rockface" as footholds.

The grade (difficulty) of the route is usually a consensus decision between the setter of the route and the first few people who climb the route. Many indoor climbing walls have people who are assigned to set these different climbing routes. These people are called route setters or course setters. As indoor climbing walls are often used to check the development of climbers' abilities, climbs are color-coded. Indoor climbing gyms may have their own grading system for convenience's and simplicity's sake, but at the same time is also typically aligned to grading systems that are recognized globally, to reflect the estimated grade that the route would be if it was an outdoor route.

Route-setting is the design of routes by placing climbing holds in a strategic, technical, and fun way that sets how the route will flow. There are many different techniques involved with setting, and up to 5 levels of certifications are awarded to those qualified. Route setting can be defined as the backbone of indoor climbing; without a great set of routes, a gym cannot easily hope to keep a good hoard of climbers.