A reference guide from CDF Distributors
This guide answers: What are the acceptable tolerances for commercial door frames?
Why Frame Tolerances Matter
A door is only as good as the frame it hangs in. Out-of-plumb, out-of-level, or racked frames cause doors to bind, drag, swing open or closed on their own, fail to latch, and wear out hardware prematurely. For fire-rated assemblies, frame tolerances directly affect the door-to-frame clearances required by NFPA 80. Getting the frame right is the foundation of a properly functioning door assembly.
Standard Tolerances
The Steel Door Institute (SDI) and the Door and Hardware Institute (DHI) publish the following tolerances for hollow metal frames:
Plumb (Vertical)
Jambs must be plumb within 1/16 inch per 3 feet of height, or 1/8 inch over the full height of the frame, whichever is less. An out-of-plumb jamb causes the door to swing toward or away from the strike side under its own weight.
Level (Horizontal)
The head of the frame must be level within 1/16 inch per 3 feet of width. An out-of-level head creates unequal gaps between the top of the door and the frame, potentially exceeding the clearance tolerances for fire-rated assemblies.
Square (Diagonal)
Measure the diagonals of the frame opening. The difference between the two diagonal measurements should be no more than 1/8 inch. A racked frame causes the door to bind at one corner while leaving excessive gap at the opposite corner.
Twist
Both jambs must lie in the same plane. Place a straightedge across the face of both jambs at the head — the faces should be coplanar within 1/16 inch. A twisted frame prevents the door from seating evenly against the stop.
NFPA 80 Clearance Requirements
For fire-rated assemblies, NFPA 80 Section 5.2.4 specifies maximum clearances:
- Top and sides: 1/8 inch maximum between door edge and frame (or per the listing)
- Meeting edges (pairs): 1/8 inch maximum
- Bottom: 3/4 inch maximum above the finished floor
These clearances assume the frame is within tolerance. An out-of-plumb frame may create a 1/4-inch gap on one side of the door while the other side binds — both conditions fail the NFPA 80 requirement.
Field Adjustment Techniques
Shimming
Steel shims placed between the frame and the rough opening correct plumb and level issues. Use steel shims (not wood) for hollow metal frames in commercial applications. Wood shims can crush over time under the weight of the frame and door, allowing the frame to shift.
Anchor Adjustment
Adjustable anchors allow the frame to be repositioned after the wall is built. Loosen the anchor, reposition the jamb, and retighten. Fixed anchors (welded or wire) require shimming instead.
Spreader Bar
A temporary spreader bar across the base of the frame prevents the jambs from bowing inward during wall construction and grouting. Remove the spreader only after the wall and anchors are fully set.
Hinge-Side Correction
If the hinge jamb is slightly out of plumb, adjusting the hinge screws can compensate for minor variations. Longer screws that reach into the stud behind the frame can pull the jamb into alignment. This is a minor correction only — do not rely on hinge screws to fix a significantly out-of-plumb frame.
A Note on Fire-Rated Assemblies
Fire-rated door assemblies are available in 20-minute, 45-minute, 60-minute, 90-minute, and 180-minute ratings. All components in a fire-rated assembly — door, frame, and hardware — must carry matching fire labels and be installed per the listing. Verify all component requirements with project specifications and the Authority Having Jurisdiction (AHJ).
Configure Your Door Assembly
CDF's ProBuilder tool allows contractors and facility managers to configure complete door, frame, and hardware assemblies online. ProBuilder displays compatible options and provides instant pricing.
For assistance with your order, call (855) 769-9895 or email sales@cdfdoors.com. CDF's sales team is available Monday through Friday, 7:30 AM to 4:30 PM CT.
Frequently Asked Questions
How do I check if a frame is plumb?
Place a 6-foot level on the face of each jamb. Check both jambs independently. The bubble should be centered within 1/16 inch per 3 feet. Also check with the level held across both jambs at the head to verify they are in the same plane (no twist).
What if the frame is out of tolerance on a fire-rated assembly?
The frame must be corrected before the door is installed. Out-of-tolerance frames create clearance violations under NFPA 80, which will be cited during fire door inspection. Shimming, anchor adjustment, or frame replacement are the options depending on the severity.
Can I adjust a frame after the wall is finished?
Limited adjustment is possible with adjustable anchors and shimming. Significant repositioning after the wall is grouted or drywalled is difficult and may require partial wall demolition. This is why verifying frame tolerances before the wall is finished is critical.
About CDF Distributors
CDF Distributors is a commercial door, frame, and hardware distributor headquartered in Nashville, Tennessee. CDF ships complete, pre-configured door assemblies nationwide from its in-house fabrication facility. Configure your assembly online at cdfdistributors.com using ProBuilder, or contact CDF at (855) 769-9895 or sales@cdfdoors.com.
