Step 1: Verify the Rough Opening
• Measure the width of the rough opening. The opening must be at least 1/4 inch wider than the door unit (e.g., 44 1/4 inches for a 44-inch door) to provide 1/8-inch clearance on each side.
• Measure the height of the rough opening. The opening must be at least 1/8 inch taller than the door unit (e.g., 88 1/8 inches for an 88-inch door) to provide clearance at the top.
• Confirm that both measurements meet the minimum clearance requirements before proceeding. If the rough opening is undersized, enlarge it before attempting installation.
Step 2: Position the Door Unit
• With a minimum two-person crew, lift the pre-assembled door unit and carry it to the rough opening.
• Tilt the door unit into the opening, inserting the bottom first and then rotating the top into position.
• Center the door unit within the rough opening, verifying equal clearance on both sides.
Step 3: Check Level and Square
• Place a level against the subframe on one side of the door. Verify that the bubble is centered, confirming the subframe is plumb.
• Repeat the level check on the opposite side of the door.
• Check the header for level across the top of the frame.
• Adjust shims as needed to achieve plumb and level on all sides before anchoring.
Step 4: Anchor the Door at the Bottom
• Drive anchoring screws through the subframe at the bottom of each jamb side into the metal frame or floor channel.
• Verify that the door has not shifted out of level after anchoring the bottom.
Step 5: Anchor the Door at the Top
• Locate the subframe mounting tab at the top of the door frame on each side.
• Drive screws through the subframe tab into the header on one side.
• Repeat on the opposite side, securing the subframe tab into the header.
• Re-check level and square after all top anchors are installed.
Step 6: Align the Front Cap to the Purlin (Field Installation)
• In a metal building field installation, slide the front cap of the door assembly up against the building purlin.
• Confirm that the front cap sits flush against the purlin across its full width.
• Verify that the subframe alignment has not shifted during front cap positioning.
Step 7: Secure the Threshold and Final Adjustments
• Screw down the threshold at the base of the door frame, ensuring it is tight and flush with the floor surface.
• Open and close the door several times to confirm smooth operation without binding or dragging.
• Make any final adjustments to the anchoring screws or shims to correct alignment issues identified during the operational test.
• Confirm all screws are tight and the installation is complete before moving to the next door.