On smaller stairs, the finished opening must be at least 4 inches larger than the diameter of the stair to allow for finger clearance. Larger stairs, 60″ diameter and above, allow 5 inches. Our platforms are made to fit square wells for this measurement and will not properly fit smaller wells.
Example: 48″ diameter stair requires a 52″ finished out square hole.
A 60″ diameter would require a 65″ finished out square hole. Optional platforms can be made to accommodate off-sized and special wells.