To begin the discussion on radius design, we need to point out that different models have different rules in regards to the radius they can be installed on and you should discuss this with your Irwin Seating representative early in the project.
The use of a radius layout can help improve sightlines. One common mistake is designing all rows with a constant radius. Doing this pinches the aisle ends together, which can compromise back to back spacing and clear passage. Using concentric radii keeps the row spacing consistent through the entire row.
When adding an incline to a radius layout, it is important to note that the concrete breaks must follow the radii. It is important that incline breaks be set in an increment of the row spacing for two important reasons:
For comfort, the chair should be installed on the same incline that the patron's foot will rest on
To ensure anchor integrity, anchors need to be set 2" from a break
In addition, an inclined radius must have a bowled floor in order to keep chair standards from "toeing" in and to keep the chair level.