How To Install an Interior Center Opening or French Door Like a Pro | Step-By-Step Guide

Category - Doors

Skill Level - 2

In new construction homes, interior center opening or French doors are an elegant and functional choice, especially for reach-in closets. These doors are designed with two door slabs that meet in the middle, providing a wide, unobstructed opening when both doors are opened. This design is particularly beneficial for closets as it maximizes accessibility, allowing for easier reach to the entire closet space. The ample opening facilitates better organization and visibility of the closet's contents, making it simpler to locate and retrieve items.

French doors for closets also add a touch of sophistication to the interior design, enhancing the aesthetic appeal of bedrooms and other areas. They often feature glass panels that can make a space feel larger and more open or solid panels for a more traditional look. The versatility in design allows these doors to blend seamlessly with various architectural styles, from modern to classic. Whether used for practical functionality in a closet or as a stylish element in room divisions, interior center opening or French doors are a popular choice in new constructions for their blend of beauty and practicality. The following guide will provide detailed instructions on how to properly install these doors, ensuring they perform well and look great in your space.

Tools Needed

• 15g finish nailer

• 6ft level

• Air compressor

• Air hose

• 4’-8’ ladder

Supplies Needed

• Wood Shims

• 15g nails

Materials

• Pre-hung double door unit

Quality Check Criteria

• Jamb is plumb on the hinge side

• Margins are consistent around the door

• Doors open and close correctly without springing (hinge-bound)

• Doors are set at the correct height to integrate with finished flooring

• Center margin between the two slabs is consistent

• Both door slabs meet flush with each other in the closed position, top to bottom

• Tops of both doors meet in the middle at the same height from the floor

• Proper latching and operation of roller catches (if applicable)

Installation Process For a French Door

Step 1: Prepare the Opening

• Assess the Space: Start by measuring the dimensions of the door opening to ensure compatibility with the pre-hung door unit. Check both the height and width at multiple points—top, middle, and bottom—to account for any irregularities in the wall.

• Clear and Clean: Remove any old framing, nails, or debris from the previous door installation. This includes trimming back any protruding drywall or other obstructions that might interfere with the placement of the new door. Use a utility knife for trimming drywall for precision and to avoid damaging the surrounding areas.
  

• Level the Base: Ensure that the threshold area—the bottom of the door frame—is level. Use a 6ft level for accuracy. If adjustments are necessary, use self-leveling compounds or additional framing techniques to create a flat, stable base for the door to rest on.
  

• Prepare for Shimming: Identify key shim points around the door frame, especially near the hinge placements and along the latch side. These points will be crucial for aligning the door correctly in later steps. Mark these areas lightly with a pencil.
  

• Safety First: During this preparation phase, wear appropriate safety gear such as gloves and eye protection, especially when handling tools or cutting materials. Ensure the workspace is well-ventilated, particularly if you're using any chemical agents for cleaning or leveling. This comprehensive preparation ensures a clean, level, and suitable environment for the new French door, setting the stage for a smoother installation process.

Step 2: Prepare the Door

• Unpack the Door Unit: Carefully remove any shipping materials that are attached to the door unit. These materials are typically used to protect the door during transportation and might include foam, cardboard, or plastic wraps.

• Inspect for Damage: Once unpacked, thoroughly inspect the door unit for any potential damage that could have occurred during shipping. Check the door slabs, frame, and any pre-installed hardware for cracks, chips, or misalignments.

• Organize the Components: Identify and lay out all components of the door unit. This includes the door slabs themselves, hardware pieces, and any additional elements that come with the pre-hung system. Ensure that all parts are accounted for as per the manufacturer’s checklist.

• Prepare the Workspace: Position the door unit near the installation site. It's important to keep the workspace organized and ensure that the door slabs are out of the way of regular traffic but accessible for the installation. Use soft cloths or a padded surface to rest the door on to prevent any scratches or damage.

• Check for Accessories: Verify that all necessary hardware, such as hinges, screws, and other mounting equipment, are present. If your door includes specialty items like roller catches or specific aesthetic features, confirm these are included and undamaged.

• Familiarize with the Door Orientation: Determine which slab is designated as the active door (the one that opens and closes most frequently) and which is the passive door. This is crucial for proper alignment during the installation, especially for double door units.

This step ensures that everything is in order before you begin the actual installation, reducing the likelihood of issues arising due to missing or damaged components.

Step 3: Shim and Secure the First Side

• Begin by positioning ¼-inch blocks beneath both jambs at the base of the door unit. These spacers are essential as they elevate the door slightly above the subfloor, which helps in preventing moisture damage and ensures that the door operates smoothly without scraping the floor.

• Choose the side of the door to start with; for doors with a latching mechanism, begin with the non-operating side. For doors utilizing roller catches, either side can be started first. Place shims just above the top hinge on the selected side, taking care to adjust the shims so that the door jamb is both plumb and square within the doorway. Achieving a perfect vertical alignment using a 6-foot level at this stage is crucial, as it ensures that the door will hang correctly.

• Once you have confirmed that the door is perfectly aligned vertically, secure the arrangement by driving two 15g nails at each shim point. Place one nail on each side of the door stop. This method of securing ensures the door remains stable and well-aligned while you proceed with the installation of the door slabs. It's important to check the alignment again after nailing to ensure that no shifting has occurred during the process.

This step sets the foundational alignment for the entire door unit, ensuring that subsequent steps proceed smoothly with the door correctly aligned for optimal operation and appearance.

Step 4: Align and Secure the First Door Slab

• Position the Door Slab: Carefully lift the first door slab and gently guide it into the frame. Align the hinge leafs with the corresponding mortises on the door jamb.

• Insert Hinge Pins: Start with the top hinge, inserting the hinge pin to connect the door slab to the frame. Follow with the middle and bottom hinges, ensuring each pin slides in smoothly and secures the door firmly.

• Check Door Swing: Gently swing the door open and closed to test its movement. It should move freely without resistance or noise. Ensure the door doesn’t spring back or bind at the hinges, which can indicate misalignment.

• Adjust for Alignment: If the door does not align perfectly with the frame or if it springs back, slightly loosen the hinge screws and adjust the position of the door slab. You may need to add or remove shims behind the hinges to achieve a perfect fit.

• Secure with Nails: Once the door is properly aligned, secure it in place by driving nails through the jamb and into the shims just above and below each hinge. Use your 15g finish nailer for a clean and secure finish.

• Verify Alignment: Use your 6ft level to check that the door is hanging straight and true. Make any final adjustments to ensure that the door slab is perfectly vertical and that the gap between the door and the frame is even all around.

By carefully aligning and securing the first door slab, you ensure that the remaining installation steps proceed smoothly, leading to a well-functioning French door.

Step 5: Stabilize and Attach Second Door

This step is crucial for ensuring the stability and proper alignment of your French door. Follow these detailed instructions to correctly attach the second door slab:

• Tack the Jamb: Begin by tacking the second jamb side to the door frame. Use a couple of 15 gauge (15g) finish nails at both the top and the bottom. This preliminary fixing will hold the jamb in place but still allows for adjustments as needed.
  

• Attach the Second Door: Carefully lift the second door slab and align it with the pre-installed hinges on the tacked jamb. Ensure that the hinges line up perfectly to avoid any misalignment. Insert the hinge pins to secure the door to the jamb.
  

• Test Door Movement: Gently swing the door to ensure it opens and closes smoothly. This test helps verify that the door is hanging correctly before fully securing it.
  

• Shim and Secure: Like in the previous step with the first door, place shims at strategic points along the jamb to ensure the door is level, square, and plumb in the opening. Start at the top and work your way down, placing shims behind the jamb at the hinge locations and other critical points as necessary.
  

• Final Securing: Once the door operates smoothly and all alignments are correct, secure the jamb permanently to the framing. Add additional 15g nails through the shims at each secure point, ensuring that each nail is driven straight and flush with the jamb surface.
  

• Check Alignment and Operation: Close both doors to check the alignment at the center and across the top. Adjustments might still be necessary to achieve a perfect fit. Ensure that the doors meet evenly and open and close without any hindrance.
  

By meticulously following these steps, the second door slab will be securely attached, and both doors will function seamlessly as a unit, enhancing both the aesthetic and practical aspects of the installation.

Step 6: Securing the Header Jamb and Final Adjustments

1. Assess and Adjust the Top Margin:
   

• Begin by examining the top margin between the two door slabs to ensure it is even across the length. The margin should be approximately ⅛ inch. Use a 6ft level to check the alignment.

• If the margin is uneven, insert shims at the head jamb to adjust the doors until they are aligned correctly. It's important to do this gently to avoid shifting the doors out of their other alignments.

1. Secure the Head Jamb:
   

• Once the doors are aligned at the top, place shims in the center of the head jamb. Check again with the level to ensure everything is straight and even.

• Nail the shims into place using the 15g finish nailer. It's crucial to nail through the shims into the framing to secure the head jamb firmly.

1. Use a Pry Bar for Precise Adjustment:
   

• For final adjustments, if the doors or jamb still show slight misalignments, gently use a pry bar at the center of the head jamb. This can help fine-tune the position before final nailing.

• Place the pry bar between the head jamb and the framing, and carefully apply pressure to adjust. This should be done incrementally to maintain control over the movement.

1. Secure with Butterfly Nails for a Precise Fit:

• Once everything is correctly aligned, secure the head jamb in place with butterfly nails. These nails provide a strong hold and help in maintaining the alignment over time.

• Nail through the jamb into the framing at strategic points to ensure stability, focusing on areas where the shims have been placed.

By following these detailed steps, you can ensure that the top of your French door is properly aligned and securely fixed, leading to a smooth operation and a professional finish.

Step 7: Complete the Installation and Apply Finishing Touches

Once the doors are securely in place and functioning correctly, it's time to move on to the final touches that will complete the installation and enhance the appearance of your French doors.

• Trim the Shims: Carefully trim any protruding shims flush with the jamb using a sharp utility knife. This ensures a neat and clean finish, preparing the doorway for the casing.
  

• Install the Casing: Follow the instructions for casing one side of a door to finish the installation.
  

• Check Operation: Do one final check of the operation of the doors again. Make sure they open and close smoothly and that all hardware functions properly. Adjust if necessary to ensure smooth operation.

• Final Cleanup: Remove any debris, dust, or construction materials from the installation area. Clean the doors, glass, and surrounding area to ensure your new French doors are sparkling and ready for use.

By following these detailed steps, your French door installation will not only be secure and functional but will also display a finished look that adds to the aesthetic appeal of your space.