Start With the Door and Frame Kit
The rough opening is the unfinished framed opening before the pocket-door frame, drywall, jambs, casing, and finished flooring are installed. Its size is not the same as the door size or the clear passage width.
Before calculating, confirm whether the project uses one door or two, the actual width and height of each door, the wall construction, the door thickness and weight, and the final floor elevation. HBP offers frame kits for 2 × 4 and 2 × 6 wall construction in single- and double-door configurations.
HBP Rough-Opening Formulas
Single Pocket Door
Width = (door width × 2) + 1′′Example: A 36′′ door needs a 73′′ rough-opening width: (36′′ × 2) + 1′′ = 73′′.
Double Pocket Door
Width = width of one door × 4Example: Two 36′′ doors need a 144′′ rough-opening width: 36′′ × 4 = 144′′.
Rough-Opening Height
Height = door height + 41⁄2′′Example: An 80′′ door needs an 841⁄2′′ rough-opening height.
How to Order the Kit
Order by actual door sizeExample: For two 36′′ × 80′′ doors, order a 36′′ × 80′′ double pocket door frame kit—not a 72′′ kit.
Common HBP Rough-Opening Sizes
| Door size | Single-door rough opening | Two equal doors: rough opening |
|---|---|---|
| 24′′ × 80′′ | 49′′ W × 841⁄2′′ H | 96′′ W × 841⁄2′′ H |
| 28′′ × 80′′ | 57′′ W × 841⁄2′′ H | 112′′ W × 841⁄2′′ H |
| 30′′ × 80′′ | 61′′ W × 841⁄2′′ H | 120′′ W × 841⁄2′′ H |
| 32′′ × 80′′ | 65′′ W × 841⁄2′′ H | 128′′ W × 841⁄2′′ H |
| 36′′ × 80′′ | 73′′ W × 841⁄2′′ H | 144′′ W × 841⁄2′′ H |
| 42′′ × 84′′ | 85′′ W × 881⁄2′′ H | 168′′ W × 881⁄2′′ H |
| 48′′ × 96′′ | 97′′ W × 1001⁄2′′ H | 192′′ W × 1001⁄2′′ H |
These are framing dimensions for HBP systems, not finished clear-opening dimensions. Confirm the exact kit instructions before construction.
HBP Rough-Opening Calculator
Enter the actual size of one door. For a double system, use the width of each individual door.
For a 36′′ × 80′′ single door: 73′′ wide × 841⁄2′′ high.
How to Lay Out the Opening Correctly
Measure the actual door
Record the slab width, height, thickness, and complete weight. Do not use the size of an existing finished doorway as the door size.
Establish the finished floor
Identify the top of the completed flooring. Tile, hardwood, underlayment, or another finish added later changes the door’s bottom clearance.
Calculate width and height
Apply the formula for the exact HBP configuration. Mark the opening on the plates and adjoining framing, then compare it with the kit instructions.
Verify the wall cavity
Confirm the pocket side is clear of plumbing, electrical boxes, ducts, blocking, structural bracing, and fasteners that would enter the door cavity.
Frame square, plumb, and level
Check both sides for plumb, the header for level, and the opening for square by comparing diagonal measurements. Correct the framing before installing the kit.
Test before closing the wall
Install, hang, adjust, and cycle the door before drywall and trim conceal the frame. The door should travel smoothly without rubbing or rolling by itself.
Finished Floor vs. Subfloor Measurements
Rough-opening height and header mounting height are related but are not the same measurement. HBP’s instructions specify a rough-opening height of 41⁄2′′ more than the door height. They also give the following layout heights for the nails that support the HBP header brackets:
| Door height | Measure from finished floor | Measure from subfloor |
|---|---|---|
| 80′′ | 803⁄4′′ | 811⁄2′′ |
| 84′′ | 843⁄4′′ | 851⁄2′′ |
| 96′′ | 963⁄4′′ | 971⁄2′′ |
Final Framing Checklist
- The selected frame kit matches the actual door size, wall thickness, door thickness, weight, and single- or double-door configuration.
- The rough-opening width and height match the current instructions for that exact kit.
- The header is adequately supported; load-bearing walls have an approved structural design.
- The header is level, both sides are plumb, and the opening is square.
- The pocket area is straight, full-depth, and free of pipes, wiring, ducts, boxes, blocking, and protruding fasteners.
- The finished floor height and desired under-door clearance have been included in the layout.
- There is enough uninterrupted wall length for the entire framed assembly—not only the visible doorway.
Common Rough-Opening Mistakes
- Ordering by rough-opening size: HBP kits are ordered by the actual door size.
- Using a single-door formula for a double door: HBP double systems have two pockets and use different width guidance.
- Ignoring the finished floor: Adding flooring later can reduce door clearance and affect the intended installation height.
- Framing before choosing hardware: Track systems, soft-close components, door weights, and manufacturer designs can change requirements.
- Accepting an out-of-square opening: A small framing error can twist the pocket, slope the track, or make the door rub.
- Putting long screws into the pocket: Drywall, trim, cabinet, or accessory screws can scratch or block the moving door.
Choose the Correct HBP Frame Kit
Standard HBP Frame Kits
Compare single and double systems for 2 × 4 and 2 × 6 walls, with several operating-hardware choices.
Shop HBP pocket door frame kitsFrame Kits With Extra Studs
Consider extra studs when the wall needs greater rigidity or planned support for suitable wall finishes or mounted items.
Shop frame kits with extra studsPremium Series Frame Kits
Review HBP’s premium-series options when the door and project call for a higher-capacity frame system.
Shop premium pocket door frame kitsInstructions and Videos
Check the latest product-specific installation information before building the rough opening.
View HBP installation resourcesThe Short Version
For an HBP single pocket door, double the actual door width and add 1′′. For an HBP double pocket door with two equal doors, multiply the width of one door by four. Add 41⁄2′′ to the door height for the rough-opening height. Then verify every measurement against the instructions for the exact kit, frame the opening square and level, and account for the completed floor before installation.