Frame alignment verification is a critical final step in hollow metal door frame installation that is frequently overlooked. A frame can appear perfectly installed when measured from the front side, with correct width dimensions and plumb readings on both jambs, yet still be out of alignment on the back side. A flared or bowed frame causes the door to bind during operation and prevents proper latching. This guide covers the complete verification procedure, including the spacer board technique used by CDF Distributors’ installation team to confirm alignment at all four contact points simultaneously.
CDF Distributors ships complete door and frame assemblies from its Nashville, Tennessee headquarters. You can configure and order online using CDF’s ProBuilder tool at cdfdistributors.com. For assistance with frame specifications or installation questions, call (855) 769-9895 or email sales@cdfdoors.com.
What Is Frame Alignment Verification?
Frame alignment verification is the process of confirming that a hollow metal door frame is square and parallel on both the front side and the back side of the wall opening. During a standard installation, installers typically measure the frame width at the top and bottom of the front face and check plumb on both jambs using a level. These front-side measurements are necessary but not sufficient. The back side of the frame, the side opposite the door stop, must also be measured to confirm that the jambs are not flared outward or bowed inward.
A frame that reads 36” across the front at both the top and bottom, with level bubbles centered on both jambs, can still measure 36-3/4” across the back. That 3/4” discrepancy means one or both jambs are flared outward at the back, creating a frame that is not truly rectangular. When a door is hung in a flared frame, it contacts the frame unevenly, resulting in binding, inconsistent gaps, and latch engagement failures.
Installation Specifications
This guide applies to standard hollow metal door frame installations where the frame has already been set into the opening and initially fastened. The verification procedure described here is performed after the frame appears to be correctly installed based on front-side measurements and level readings. The measurements referenced in this guide use a 3’0” x 7’0” (36” x 84”) door opening as the example, though the same verification method applies to any standard frame size.
At a Glance
Procedure | Frame alignment verification (front and back side measurement) |
Applies To | All hollow metal door frames (drywall wrap, masonry, welded) |
Reference Door Size | 3’0” x 7’0” (36” x 84”) |
Critical Measurement | Back-side frame width must match front-side frame width exactly |
Primary Tool | Spacer board (plywood with cutouts for door stops) |
Verification Points | Four simultaneous contact points (top and bottom of both jambs) |
Failure Symptom | Door binds, inconsistent reveal gaps, latch does not engage |
What Is the Spacer Board Technique?
The spacer board technique uses a piece of plywood or dimensional lumber cut to the exact door width with notches or cutouts on each end that wrap around the door stops on both jambs. When placed horizontally inside the frame opening, the spacer board contacts all four points of the frame simultaneously: the front and back of the left jamb, and the front and back of the right jamb. If the board seats flush against all four points, the frame is square. If any point has a gap, the frame is out of alignment at that location.
The cutouts in the spacer board are sized to fit around the door stop (rabbet) that protrudes into the frame opening. This allows the board to engage both the front face and the back face of each jamb at the same time. Without these cutouts, a straight board would only contact one plane of the frame, which is exactly the limitation of standard tape-measure verification.
Cross-section diagram showing spacer board with cutouts seated against both jambs, engaging all four contact points (front-left, back-left, front-right, back-right). This diagram requires CDF approval before inclusion in the production file.
Tools and Materials
- Tape measure: for measuring front-side and back-side frame widths
- 4-6 foot level: for verifying plumb on both jambs
- 2-foot level: for verifying level on the header
- Spacer board: a piece of plywood or dimensional lumber cut to the exact door width with cutouts on each end to wrap around the door stops; contacts all four jamb points simultaneously
- Impact drill: for removing and reinstalling frame screws during correction
- Screws: replacement screws for re-anchoring the frame after adjustment
- Saw: for cutting the spacer board to the correct width and creating the stop cutouts
Step-by-Step Frame Alignment Verification
Step 1: Verify Front-Side Measurements
Begin by confirming the front-side measurements that most installers already check. These measurements establish the baseline and confirm the front face of the frame is correct before moving to the back side.
- Measure the frame width at the bottom of the opening on the front side. For a 3’0” door, this measurement should read exactly 36”.
- Measure the frame width at the top of the opening on the front side. This should also read exactly 36”.
- Place a level on the hinge jamb and verify the bubble is centered.
- Place a level on the strike jamb and verify the bubble is centered.
- Place a level on the header and verify it reads level.
At this point, the frame appears correctly installed from the front side. All width measurements match, and all level readings are centered. This is the stage at which many installers consider the frame done. It is not.
Step 2: Measure the Back Side of the Frame
The back side of the frame is the side opposite the door stop, where there is no strike plate or hinge hardware. Because there are no hardware contact points on this side, installers frequently skip this measurement. This is where alignment problems hide.
- Measure the frame width at the bottom of the opening on the back side.
- Measure the frame width at the top of the opening on the back side.
- Compare the back-side measurements to the front-side measurements. They must match exactly.
If the front side measures 36” and the back side measures 36-3/4”, the frame is flared outward by 3/4” on the back. One or both jambs are pushed out at the back, creating a frame that is wider at the back than at the front. This condition will cause the door to bind during operation.
Step 3: Build and Use a Spacer Board
Rather than relying solely on tape-measure checks, build a spacer board that verifies all four contact points at once. This eliminates the possibility of correcting one measurement while inadvertently creating a new problem at another point.
- Cut a piece of plywood or a dimensional board to the exact door width (36” for a 3’0” door).
- Cut notches or cutouts on each end of the board so it fits around the door stops (rabbets) on both jambs.
- Slide the spacer board into the frame opening horizontally.
- Verify that the board contacts all four points: the front face of the left jamb, the back face of the left jamb, the front face of the right jamb, and the back face of the right jamb.
- If any point does not contact the board, the frame is out of alignment at that location.
The spacer board does not need to be finished or polished. It only needs to be cut accurately. As long as the distance between the notched ends equals the exact door width, it will function correctly as an alignment verification tool.
Step 4: Correct a Flared Frame
If the back-side measurements do not match the front side, or if the spacer board does not seat flush at all four points, the frame must be corrected before hanging the door.
- Remove the levels from the frame to prevent them from falling during the correction process.
- Remove the screws from the back side of each jamb at the base.
- Push the jambs inward until the spacer board contacts all four points evenly.
- With the spacer board holding the frame at the correct width, reinstall the screws to anchor the jambs in the corrected position.
- Remove the spacer board and re-measure both the front side and the back side to confirm they now match.
Step 5: Re-Verify Plumb and Level After Correction
After correcting the frame alignment, all plumb and level readings must be re-checked. Adjusting the jamb positions can shift the frame slightly, so verification is required even if the frame was plumb before the correction.
- Place the level on the hinge jamb and confirm the bubble is centered.
- Place the level on the strike jamb and confirm the bubble is centered.
- Place the level on the header and confirm it reads level.
- Reinsert the spacer board and confirm all four contact points are flush.
Once all plumb and level readings are correct and the spacer board seats flush at all four points, the frame is properly aligned and ready for door installation.
Common Mistakes to Avoid
The following errors are the most frequent causes of frame alignment problems:
- Only measuring the front side. This is the single most common frame alignment mistake. A frame can read correctly on the front at both the top and bottom, with level bubbles centered on both jambs, and still be significantly flared on the back side. Always measure both sides.
- Assuming plumb means square. A jamb can be perfectly plumb (vertical) while being rotated or twisted in the opening. Plumb confirms the jamb is vertical but does not confirm that the front and back faces are parallel to the opposite jamb.
- Skipping the spacer board. Measuring with a tape measure checks one dimension at a time. A spacer board with cutouts checks all four contact points simultaneously, revealing problems that sequential measurements can miss.
- Not removing levels before correction. Levels placed on the frame can fall during adjustment and cause injury or damage. Remove all levels before loosening screws or pushing on the frame.
- Failing to re-verify after correction. Pushing jambs inward to correct a flare can shift the frame out of plumb. Always re-check all measurements and level readings after any adjustment.
- Ignoring the back side because it has no hardware. The back side of the frame has no strike plate or hinge locations, which leads installers to treat it as less important. The back side determines the overall frame geometry just as much as the front side.
Fire-Rated Frame Considerations
Frame alignment verification applies equally to fire-rated and non-rated frames. A misaligned fire-rated frame can compromise the seal between the door and frame, which is critical for maintaining the rated assembly’s integrity during a fire event. Hollow metal door frames are available in fire ratings of 20, 45, 60, 90, and 180 minutes (3 hours). All components in a fire-rated assembly, including the door, frame, hardware, glass, and glazing materials, must carry matching fire labels. CDF Distributors rivets fire labels onto every fire-rated assembly before shipping.
Verify all fire-rating requirements with project specifications and the Authority Having Jurisdiction (AHJ).
Configure Your Assembly
CDF’s ProBuilder tool allows contractors and facility managers to configure complete door and frame assemblies online. ProBuilder displays compatible options for door, frame, and hardware selections and provides instant pricing. During configuration, ProBuilder calculates frame dimensions and rough opening requirements automatically.
For assistance with your order or questions about frame alignment verification, 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
Why does my frame look square but the door still binds?
The most likely cause is that the back side of the frame is not aligned with the front side. A frame can measure correctly at the front, with level bubbles centered on both jambs, and still be flared or bowed on the back. Measure the frame width on the back side and compare it to the front. Any discrepancy indicates a flared frame that must be corrected before the door will operate properly.
How do I build a spacer board for frame alignment?
Cut a piece of plywood or dimensional lumber to the exact door width. Then cut notches or cutouts on each end so the board wraps around the door stops (rabbets) on both jambs. The board should contact all four points of the frame simultaneously: front and back of both jambs. No finishing or painting is required. The only requirement is that the distance between the notched ends matches the door width exactly.
What measurements should I check on both sides of the frame?
Measure the frame width at the top and bottom on the front side, then repeat the same measurements on the back side. All four measurements should be identical and equal to the door width. For a 3’0” door, all four measurements should read 36”. If the back-side measurement differs from the front, the frame is flared and must be corrected.
Can I fix a flared frame without removing it from the wall?
Yes. Remove the screws at the base of each jamb on the back side, push the jambs inward until the spacer board contacts all four points evenly, then reinstall the screws. This corrects the flare without removing the entire frame from the opening. Re-verify all plumb and level readings after the correction.
Does this verification apply to masonry frames as well as drywall frames?
Yes. Frame alignment verification applies to all hollow metal frame types, including drywall wrap-around frames, masonry frames, and welded frames. The spacer board technique works with any frame that has door stops (rabbets) on the jambs. The correction method may differ depending on the frame type and anchoring method.
How much misalignment is acceptable?
Front-side and back-side measurements should match exactly. Any measurable discrepancy between the front and back indicates a flared or bowed frame. Even a 1/4” difference can cause door binding, inconsistent reveal gaps, and latch engagement problems. Correct any measurable misalignment before hanging the door.
About This Guide
This frame alignment verification procedure reflects CDF Distributors’ field-tested installation method used by commercial contractors nationwide. The procedure addresses one of the most commonly overlooked steps in hollow metal frame installation: verifying that the back side of the frame matches the front side. The full demonstration video is available on CDF’s YouTube channel at youtube.com/@CDF_Distributors.
For questions about frame alignment or to order a door and frame assembly, contact CDF at (855) 769-9895 or sales@cdfdoors.com. Configure your assembly online at cdfdistributors.com using ProBuilder.
