Dorsis Belport step-by-step installation

Assemble the Dorsis Belport pocket door box on a level surface.
Space the horizontal reinforced bars about 17 inches ( 440 mm) apart and attach them to the vertical front and back profiles. Lock the horizontal bars in the upside down keyhole mount; you will not need additional anchoring pieces.
*Only for Dorsis Belport specified for a 6" thick wall (150 mm): First, use the distance spacers underneath the horizontal reinforced bars. Then, clip-in each horizontal reinforced bars by pushing it down in the upside down keyhole of the distance spacer.
Mount the header profile with the track to the top part of the pocket box using the attached corner connecting pieces and anchor screws.
Place white EPS blocks in between the horizontal reinforced bars — the EPS block is universal for 4", 5", and 6" pocket door walls (100/125/150 mm).
Slide in the horse shoe-shaped plastic profile CW75/100 into the bottom of the split jamb (vertical reinforced bar). This element will allow you to install the bottom guide post later in the installation process.
Screw in the corner connecting pieces to the outer frame.
Attach the receiving jamb (lock-side solid jamb) to the pocket door header profile with the track attached to the pocket door box.
Affix horizontal installation braces to the solid and split jamb — the braces will help set and keep the correct nominal opening for the installation into rough opening.

Confirm the rough opening is sized correctly for the nominal size of the door you are installing.
Confirm the rough opening has a load bearing header.
If the floor is unfinished (you only have subfloor), you must build a foundation (use OSB or suitable alternative) for the pocket door box. Set the foundation ⅜" (10 mm) lower than the finished floor level. The foundation must be underneath the pocket door box and underneath the lock-side jamb.
Place a fully assembled Belport pocket door box into the rough opening.
Use a 3-beam line laser level and check the pocket door box aligns with your walls. Use shims to adjust and fix the position.
Set the bottom side of the pocket door box at the finished floor level (0 mm offset). It is permissible to set the bottom of the pocket door box a few millimeters under the finished floor level, however, you must consult this step with the flooring company as they won't be able to slide the flooring board under the pocket door jambs.
Affix the leveled and shimmed pocket door box to the studs in your R.O.

Using the included 3.9x19 mm screws, attach a ½" OSB board or drywall to the horizontal reinforced bars. The pocket box is now ready for the floor installation if needed.
Attach the second ½" layer of the double layer drywall (if using 5" or 6" version of the pocket door). Fill the gaps with drywall compound. The 4" (100 mm) version only uses a single layer of drywall.
With the drywall work completed, release the installation braces from the door opening and remove the white EPS blocks from the pocket door box cavity.
Finish the split jamb trim — we recommend fiber-reinforced drywall compound such as 3M High Strength Large Hole Repair to help create a stronger connection and prevent cracks.