User talk:Bleachers

STRUCTURE
Bleachers consist of tiered seating and steps with the fans sitting side by side on seat boards. Tiered seating occurs on more than one elevation in the same structure and includes grandstands, bleachers, telescoping and folding seating.

From small movable aluminum benches to giant grandstands that cannot be moved, bleachers have flexibility unlike any spectator seating. They are constructed with supports with a space or gap underneath.

Since there is no covering, the term bleachers came from the sun “bleaching” out the spectators and seats.

Outdoor bleachers range from smaller 3 and 4 rows to larger permanent angle/tube frame structures. Angle/tube frame bleachers were intended to be movable, but can be permanent by fixing firmly to a concrete slap or ribbon footing. Bleachers which are erected for a period of less than 180 days in a calendar year are considered temporary installations.

CONSTRUCTION
Bleacher support frames are generally constructed out of an aluminum angle design or welded galvanized steel. In the bleacher industry it is believed that aluminum tube frames have more durability and strength.

Most modern bleacher benches are extruded aluminum. The walking surface is called a footboard. Most tread planks are mill finished. Seat/riser planks generally have a clear anodized finish. Manufacturers offer mostly standard 3, 5, 10 and 15 row non-elevated units that come in standardized lengths. Custom units can come with longer lengths. Elevated units can also be obtained.

TELESCOPIC SEATING
Indoor gyms can have telescopic bleachers and or retractable platforms which are semi-automatic chair operation systems. Tiered seating that has an overall size and shape which is reduced for moving or storage is called telescopic seating. The ease of the set up and take down features of this seating greatly decreases the time it takes to change a multipurpose facility from full seating to a full floor space. A wall attached system is the most usual retractable seating system. The system is attached directly to a wall with the bleacher moving away from the wall. This can be manually operated ( up to 10 rows) or motorized.

Semi-automatic chair operations can allow up to 14 chairs to be moved in sync. Featured is a fully-automatic lowering mechanism and a spring-assisted raising mechanism. This improves dramatically the changeover efficiency and the set-up. Generally from the wall to the end of the bleachers (including rails) no less than 2 ½” is needed. Floor point loads should not be less than 250 lbs.

SAFETY GUIDELINES
Tiered seating should be inspected at least once a year by a qualified technician to verify that the structure is maintained in compliance with standard safety codes. Telescopic and folding seating should comply with operational and installation instructions of the manufacturers.

For requirements of local building codes, manufacturers offer optional features.

Code officials verify that local seating codes are enforced. Back to back spacing minimums are enforced to provide an unobstructed path of travel from any point in a structure to a public walkway.