Dimensions and Measurements for commercial egress stairs
Standard product details STANDARD PRODUCT DETAILS
Typical details for our commercial egress stairs with standard product options.

Standard stringer and rail design
❶ | 48" maximum distance between posts |
❷ | 7" maximum riser height |
❸ | 11" tread depth |
A | ¼" Closure Plates |
B | Dewalt Power Stud |
C | For Landing Connection |
D | Handrail (1½ OD 13 ga tube) |
E | Top Rail (1½ OD 13 ga tube or 1¼ sched 40 pipe) |
F | ⅝" Handrail Bracket |
G | Knee Rail (1½ OD 13 ga tube or 1¼ sched 40 pipe) |
H | Top Grab Rail (either continuous to next flight or 12" horizontal extension) |
I | Post (1½ OD 13 ga tube or 1¼ sched 40 pipe) |

Standard rail design
❶ | 12" hand rail extension length |
❷ | 12" hand rail extension height |
❸ | 3¼" knee rail to stringer |
❹ | 1½" top of stringer to top of tread |
❺ | 1½" bottom post to bottom edge of stringer |
❻ | 1¾" top post to top edge of stringer |
❼ | 36" handrail height |
❽ | 42" guard rail height |

Round pipe rail frame, picket infill
❶ | 48" maximum distance between posts |
❷ | Variable slope (determined by code) |
❸ | 4" sphere maximum opening |
❹ | ¼" fillet weld |
❺ | 42" top rail height |
A | 1½ OD 13 ga tube rail frame |
B | ¼" to ½" square or round picket infill |

Square tube rail frame, picket infill
❶ | 48" maximum distance between posts |
❷ | Variable slope (determined by code) |
❸ | 4" sphere maximum opening |
❹ | ¼" fillet weld |
❺ | 42" top rail height |
A | 1¼" schedule 40 pipe rail frame |
B | ¼" to ½" square or round picket infill |

Multi-line infill 7-LINE, EQUALLY SPACED
❶ | 48" maximum distance between posts |
❷ | Variable slope (determined by code) |
❸ | 4" sphere maximum opening |
❹ | ¼" fillet weld |
❺ | 42" top rail height |
A | 1.66" OD x .140 round tube rail frame and infill |

Mesh panel infill WELDED TO THE RAIL FRAME
❶ | 48" maximum distance between posts |
❷ | Variable slope (determined by code) |
❸ | 4" sphere maximum opening |
❹ | ¼" fillet weld |
❺ | 42" top rail height |
A | 1½ OD 13 ga tube rail frame |
B | 2" #6 wire mesh with 1" u-channel frame panel infill |

Concrete pan treads
❶ | 1" tread overlap |
❷ | 11" tread depth |
❸ | 1½" from top of tread to top of stringer |
❹ | 1½" thick tread |
❺ | 7" max tread height |
❻ | ⅛" fillet weld; 1½" long |
A | Formed sheet steel treads and risers at specified thickness |
B | 1½" site-filled concrete (not provided by Lapeyre Stair) |
Wire mesh is not required for concrete with a minimum strength of 4,000 PSI. Wire mesh (if required) is not provided by Lapeyre Stair. Standard design does not include provisions for loose, field-poured nosings. If nosing provisions are required, they must be specified; these nosings are not provided by Lapeyre Stair. |

Diamond plate treads
❶ | 1" tread overlap |
❷ | 11" tread depth |
❸ | 1½" from top of tread to top of stringer |
❹ | 7" max tread height |
❺ | ⅛" fillet weld; 1½" long |
A | Formed diamond plate treads and risers at specified thickness |

Bar grate treads 10W4 or 19W4
❶ | 12⅛" tread depth (including tread overlap) |
❷ | 1¼" nosing |
❸ | 10½" bar grate surface depth |
❹ | 1⅝" nosing |
❺ | 10⅞" bar grate surface depth |
❻ | Variable tread width (as specified) |
A | Extended surface when closed risers are specified |
B | 3/16" standard bar width; 1 or 1½" bar depth (as specified) |
C | Choice of smooth or serated grating |
Standard connection details STANDARD CONNECTION DETAILS
Typical details for common types connections for installing our commercial egress stairs.

Stair to slab connection
❶ | ¼" fillet weld |
❷ | 11/16" |
❸ | Variable based on specifications |
A | Concrete slab |
B | Channel stringer (MC 12X10.6) |
C | DeWalt Power-Stud SD1 (¾"X5½") |

Landing connection
❶ | ½" parallel minimum clearance |
A | ¼" gusset |
B | Leg angle (L3X3X¼) |
C | DeWalt Power-Stud |
D | Concrete or CMU (customer-filled at landings) |

Hanger rod landing supports
❶ | ¼" fillet weld |
❷ | ¼" flare bevel weld (both sides) |
❸ | ½" parallel |
❹ | ¼" fillet weld (tack weld) |
A | ½" steel plate (embed) |
B | Nelson S3L bolt (¾") |
C | Leg angle (L6X4X⅜) |
D | Hanger rod (¾" or 1" diameter) |
E | Stud wall |
F | Extended header |
G | Leg angle (L3X3X¼) |
H | ⅛" steel plate |

Shelf angle landing supports
❶ | ½" parallel |
❷ | ¼" fillet weld (both sides) |
A | Concrete or CMU (customer-filled at landings) |
B | Channel stringer (MC 12X10.6) |
C | ¼" gusset plate |
D | Leg angle (L6X4X⅜) |
E | DeWalt Power-Stud |

Direct bolt through landing supports
❶ | ½" parallel maximum clearance |
A | Concrete or CMU (customer-filled at landings) |
B | Leg angle (L3X3X¼) |
C | DeWalt Power-Stud |
No shelf angles; the landing is anchored directly to the wall through the side body. |

Column landing supports
❶ | ½" parallel |
❷ | ¼" fillet weld |
A | Stud wall |
B | ⅛" steel plate |
C | Extended header |