How to install a door?

Installing a door is not especially complicated, but yes, it does require following some steps precisely and accurately. 

At McClellands Contracting and Roofing, LLC, we are your local home improvement contractors serving Pittsburgh and the surrounding areas of Pennsylvania. 

In today's article, we will go over how to install a door on your property.

For a no-obligation discussion about door installation in Pennsylvania, feel free to call us today at (412) 353-5660.

What Are The Tools Needed for a Door Installation?

Before you start installing a door, gather these tools for a smooth process.

👉 Measuring tape (for precise measurements)

👉 Level (to ensure everything is straight)

👉 Hammer (for nailing components)

👉 Screwdriver 

👉 Power drill with appropriate bits

👉 Wooden shims (for leveling and adjustments)

👉 Finish nails (8d size works well)

👉 Utility knife (for scoring and trimming)

👉 Pry bar (when removing existing trim)

👉 Chisel (for creating hinge mortises)

👉 Hand plane or circular saw (for door trimming if needed)

Having these tools ready before you start installing a door will save you multiple trips to the hardware store and keep your project moving forward.

How To Install A Pre-hung Door

Pre-hung doors come ready to install, with the door already mounted in its frame with hinges attached. Installing a pre-hung door is one of the most common door installation projects homeowners do themselves. 

Follow these easy steps to install a prehung door:

Step 1: Remove the Existing Door and Prepare the Opening

Begin your door installation by carefully removing the old door and frame.

👉 Insert a stiff putty knife between the trim and wall to loosen it.

👉 Place a small block of wood behind your pry bar to protect the wall as you remove the trim.

👉 Work slowly around the perimeter, saving the trim if it's in good condition.

👉 After removing the trim, use the pry bar to detach the side jambs from the studs.

👉 Finally, remove the head jamb to complete the opening.

Step 2: Level the Floor and Opening

Once you've created a rough opening, use your level to check if the floor is perfectly straight where the door will sit. This step is very important because an uneven floor will cause your door to swing unpredictably.

👉 Place your level on the floor where the door is going.

👉 If the hinge side is lower than the latch side, add wooden shims underneath until the level reads perfectly straight.

👉 Secure these shims with finish nails so they don't shift during the installation.

👉 Next, check if the rough opening is plumb (vertically straight) on the hinge side.

👉 Add shims between the rough opening and your level until it reads plumb.

👉 Nail these shims in place to maintain the proper alignment.

These preliminary leveling steps may seem tedious, but they're very important for proper door installation. A door hanging in an uneven opening will not function correctly.

Step 3: Position and Test-Fit the Pre-hung Door

After preparing the opening, it's time to test how your new door fits.

👉 With a helper, carefully lift the prehung door into the rough opening.

👉 Center it as much as possible, making sure the door swings in the desired direction.

👉 Push the door until the frame is flush against the rough opening on both sides.

👉 Check that there's a consistent gap between the door and the frame all the way around.

This test fit helps you identify any potential problems before permanently securing the door. Look for places where the frame might not sit flush or where additional shimming might be needed.

Step 4: Secure the Hinge Side First

When installing a door, always secure the hinge side first:

👉 With the door in position, locate where each hinge sits on the frame.

👉 Drive a nail through the frame near each hinge, going through the frame and into the rough opening.

👉 Don't drive these nails all the way in yet as you might need to make adjustments.

👉 Open and close the door to verify it swings properly without sticking.

👉 If the door functions well, finish driving the nails into the hinge side jamb.

Securing the hinge side first creates a solid pivot point for your door, making the rest of your door installation much easier.

Step 5: Level and Secure the Latch Side

With the hinge side secured, focus on the latch side:

👉 Close the door and check the gap between the door and frame on the latch side. This gap should be consistent from top to bottom, about ⅛-inch is ideal.

👉 Place shims between the jamb and rough opening at the top, middle (at latch height), and bottom.

👉 Adjust these shims until the jamb is perfectly straight and the gap is consistent.

👉 Drive finish nails through the jamb and shims at each shimming point.

👉 Open and close the door again to verify smooth operation.

The latch side alignment is crucial for proper door closure. An improperly aligned latch side will cause the door to catch or not latch correctly.

Step 6: Install the Door Trim

After securing both sides of the door frame:

👉 Cut your trim pieces to the correct length for each side of the door.

👉 Nail the trim to the jamb and wall studs using finish nails.

👉 Space these nails about 16 inches apart for proper holding power.

👉 For a clean look, trim any exposed shims flush with the wall by scoring with a utility knife and snapping them off.

👉 Repeat the trim installation on both sides of the door.

The trim provides structural support to your door installation by securing the jamb to the wall surface.

Step 7: Install the Door Knob and Hardware

Complete your door installation with the hardware.

👉 Locate the pre-drilled holes in your pre-hung door for the knob and latch.

👉 Insert the latch mechanism with the angled side facing in the direction the door closes.

👉 Secure it with the provided screws, being careful not to overtighten.

👉 Connect the doorknob halves through the door, aligning the connecting rod with the latch.

👉 Fasten the knobs together with the connecting screws.

👉 Install the strike plate on the jamb, aligning it with the latch.

Test the door by closing and opening it multiple times to ensure a smooth operation. The latch should engage with the strike plate easily when the door closes.

How to Install a Door Slab

Installing a door slab requires more precision than a pre-hung door but can save you money. Follow these steps for a professional result:

Step 1: Take Precise Measurements

Accurate measurements are critical when installing a door slab.

👉 Measure the width and height of your doorframe in multiple places.

👉 The doorframe should be approximately ¼-inch larger than your door in both dimensions.

👉 If your new door is too large, mark where you'll need to trim it.

👉 For minor trimming (less than 1/8 inch), a hand plane works best.

👉 For larger adjustments, carefully mark the cut line with painter's tape and use a circular saw.

👉 When reducing the door height, always trim from the bottom.

👉 If adjusting the width, remove equal amounts from both sides to maintain the door's balance.

Taking multiple measurements helps identify any irregularities in your doorframe that might affect your door installation.

Step 2: Mark Locations for Hinges and Hardware

Precise marking is very important because it helps your hardware align perfectly.

👉 If replacing an existing door, use it as a template by placing it on top of your new door.

👉 Mark the hinge locations by scoring the outline with a utility knife.

👉 For the doorknob, trace the existing hole onto your new door.

👉 Mark the latch location on the edge of the door.

For extra precision, clamp the doors together during marking. These markings will guide your cutting and drilling, ensuring everything aligns correctly when you install the door.

Step 3: Create the Lockset Holes

Creating clean, precise holes for your door knob is essential.

👉 Use a hole saw attachment on your drill to cut the main doorknob hole.

👉 Start drilling from one side, going only halfway through the door.

👉 Flip the door over and complete the hole from the opposite side.

👉 For the edge latch hole, use a spade bit that matches the latch size.

👉 Test fit the latch mechanism to verify it sits flush with the door edge.

The two-sided drilling approach is a professional technique that creates much cleaner results than drilling straight through from one side. 

Step 4: Create Hinge Mortises

Creating precise mortises for the hinges is one of the most critical steps when installing a door slab.

👉 Place the hinge in the position where you marked earlier.

👉 Trace around it with a sharp pencil or utility knife.

👉 Hold your chisel at a 90-degree angle with the bevel facing down.

👉 Tap gently with a hammer to remove wood within the traced outline.

👉 Work slowly, checking the depth frequently by placing the hinge in the mortise. The hinge should sit perfectly flush with the door surface.

👉 Remove any splinters or rough edges for a clean finish.

Take your time with this step. Poorly cut mortises will cause your door to hang improperly and potentially bend when opening or closing.

Step 5: Attach Hinges and Hang the Door

With your preparations complete, you can now hang your door.

👉 Screw the hinge leaves into the mortises you created on the door.

👉 Position the door near the frame, supporting it on wooden blocks to align it with the frame.

👉 Mark the corresponding hinge positions on the door frame.

👉 Create mortises in the door frame like you did on the door.

👉 Attach the remaining hinge leaves to the frame.

👉 With help, lift the door and align the hinge knuckles.

👉 Insert the hinge pins, tapping them gently with a hammer if needed.

After hanging, open and close the door multiple times to check if it's functioning properly. Make any needed adjustments before proceeding to the final step.

Step 6: Install the Lockset

Complete your slab door installation by adding the locking hardware:

👉 Insert the latch mechanism into the edge hole, ensuring the angled side faces the direction the door closes.

👉 Secure the latch faceplate with screws.

👉 Insert the connecting rod through the latch from one side.

👉 Attach both doorknob halves and secure them with the connecting screws.

👉 Mark and install the strike plate on the doorframe, aligning it carefully with the latch.

👉 Test the completed installation by opening, closing, and locking the door several times.

A properly installed lockset should operate smoothly without sticking or requiring excessive force.

How to Install a Door Frame

When installing a door, sometimes you need to replace the frame as well. Here's how to install a door frame.

Step 1: Prepare the Rough Opening

Before you can install a door frame:

👉Remove any existing frame completely.

👉Check the size of the rough opening. It should be about 2 inches wider and 2 ½ inches taller than the door itself.

👉 Verify that the floor is level where the frame will sit.

👉 Check that the rough opening sides are plumb and the top is level.

A properly sized and squared rough opening makes door frame installation pretty easy.

Step 2: Assemble the Frame

Most door frames come unassembled, so you will need to assemble it before installation.

👉 Lay out the head jamb and two side jambs on a flat surface.

👉 Apply wood glue to the ends of the side jambs.

👉 Join the pieces together to form a U-shape.

👉 Secure the corners with finish nails or the provided fasteners.

👉 Allow the glue to set before handling the assembled frame.

Proper assembly creates a rigid frame that will reliably support your door.

Step 3: Position and Secure the Frame

With your frame assembled, it's time for installation.

👉 Stand the frame in the rough opening.

👉 Center it with equal gaps on both sides.

👉 Use shims to adjust the frame until it's perfectly level and plumb.

👉 Secure the hinge side first, placing fasteners through the jamb and shims.

👉 Check that the frame remains square before securing the latch side.

👉 Verify all measurements before completing the fastening.

The most critical aspect of door frame installation is ensuring the frame remains perfectly square throughout the process.

Step 4: Finish the Installation

Complete your door frame installation:

👉 Install the doorstop molding on the frame.

👉 Add any additional weatherstripping for exterior door frames.

👉 Fill nail holes with wood putty.

You're now ready to hang a door in your newly installed frame. A properly installed door frame provides the foundation for smooth door operation.

Common Door Installation Mistakes and How to Avoid Them

Even experienced DIYers can make mistakes when installing a door. Here are the most common issues and how to prevent them:

#1 Not Checking if the Frame is Square and Level

A common mistake in door installation is failing to check if the opening and frame are perfectly square and level. This leads to doors that swing open or closed on their own or that stick during operation.

Solution: Use your level constantly throughout the installation process. Check for level and plumb at multiple points and make adjustments with shims as needed.

#2 Insufficient Shimming

Proper shimming is essential for door installation. Skimping on shims or placing them incorrectly leads to frame movement and door misalignment over time.

Solution: Use pairs of shims (thin end to thin end) to create a solid support. Place shims near hinge points and the latch to prevent frame flexing.

#3 Improper Hinge Mortising

When installing a door slab, creating hinge mortises that are too deep or too shallow will cause alignment problems.

Solution: Take your time with mortising. Check the depth frequently by placing the hinge in the recess to ensure it sits perfectly flush with the surface.

#4 Overtightening Hardware

Screwing door hardware too tightly can warp components and cause the door to stick.

Solution: Tighten screws just until they're snug. Test operation frequently during installation and back off slightly if you notice issues opening or closing the door.

Also Read: Shower Curtains Or Glass Doors: Which is Better?

Get Professional Door Installation In Pennsylvania

At McClellands Contracting and Roofing, LLC, we're always available to help with your door installation needs in Pittsburgh and the surrounding areas of Pennsylvania. 

Whether you're tackling a DIY project or need professional assistance, we hope this comprehensive guide has provided insights into the door installation process.

However, if you are looking for a trusted partner who can efficiently handle your property’s door installation in Pennsylvania, reach out to us at (412) 353-5660.