How to replace a door frame like a pro: Step-by-step guide

If you have a damaged or old door frame, replacing it might seem like a big job, but with the right tools, you can do it yourself and save on labor costs.

In this article, we’ll walk you through how to replace a door frame from start to finish. We’ll also explain when it’s best to repair versus when to replace door frames.

When to replace a door frame

Door frames can wear out over time due to moisture, physical damage, or aging. Knowing when to replace a door frame instead of just repairing it can save you from more significant problems down the line. Look for things like:

• Visible rot or soft spots: If you notice rot or soft spots that you can easily poke or press into with your finger, moisture has likely compromised the wood and weakened the frame’s structure, making it difficult to repair. In such cases, replacing the frame is the only long-term solution.
• Misalignment and shifting: Houses can settle or shift, causing the door frame to become misaligned. If the door scrapes and doesn’t fit into the frame properly, it’s a sign to look out for. Minor misalignment can be corrected with shimming or adjustments, but severe misalignment requires frame replacement.
• Cracks or splits: Cracks or splits in the frame develop due to temperature fluctuations, humidity, or age. Small cracks can be easily repaired with wood fillers, but more significant splits or severe deformation can compromise the frame's strength and require replacing.

What you'll need before getting started

Gather these tools and materials to make your door frame replacement easier and prevent unnecessary delays.

• Hammer 
• Pry bar
• Screwdriver or drill
• Measuring tape
• Level 
• Handsaw or circular saw
• Gloves, safety glasses, and a dust mask 
• New door frame or pre-hung door
• Wood shims
• Finishing nails or screws 
• Caulk or weatherstripping
• Wood sealer or primer 
• Paint or stain

How to measure a door frame for replacement

Three key dimensions: width, height, and jamb depth. Getting these right ensures your wooden door frame replacement fits properly and works as it should.

First, measure the width of the door frame at the top, middle, and bottom. The widest measurement is the correct one to use. Next, measure the height from the floor to the header. Finally, measure the jamb depth to determine how far the frame extends into the wall.

Accurate measurements of all three dimensions are vital because even minor discrepancies can lead to problems during installation. The door may not fit properly if the frame is too small or too large. Moreover, incorrect measurements can complicate the installation process, leading to additional costs for adjustments or replacements.

How to remove a door frame

Removing a door frame requires careful attention to detail to avoid damaging the surrounding wall or structure. Here’s a step-by-step guide for you.

• Remove the door and hardware: Open the door fully and unscrew the hinges from the door frame using a screwdriver or drill. Then, carefully lift the door off the frame and set it aside. Next, unscrew any hardware like locks, handles, or latches from the door and set these aside for reuse or disposal. You might need someone to steady the door while removing the hinges. 
• Detach the trim and cut the old jamb: Score the paint or caulk along the edges where the trim meets the wall using a utility knife to prevent damaging the drywall when you remove the trim. Then, use a pry bar or crowbar to gently pull the trim away, starting at one end and working around the frame. Be careful not to damage the trim if you plan to reuse it. After removing the trim, use a reciprocating saw or handsaw to cut through the jamb. Begin at the top or bottom and work your way up, cutting around any nails holding it. 
• Clear nails, shims, and old fasteners: Now, use a pry bar or hammer to remove any nails or screws that are still holding the frame in place. You also need to remove the shims in place to keep the frame aligned. If stubborn, use pliers or a crowbar to pry them out carefully.
• Prep the rough opening: After removing the frame, clear the rough opening of nails, shims, and debris and ensure it is square and level. Repair any damage to the drywall or studs with joint compound.

Installing the new door frame

Whether you're replacing the entire frame or installing a prehung door, careful measurements and alignment are required to ensure proper function.

• Dry fitting the frame or prehung door: Place the replacement door frame or prehung door into the rough opening and ensure it’s centered within the opening with enough clearance on all sides. Check that the frame is square and the door swings freely without obstruction.
• Insert shims and check for plumb: Insert shims between the frame and the rough opening, starting at the top, then on the sides, and finally at the bottom. Use a level to check that the frame is plumb vertically and level horizontally. Adjust the shims until the frame is aligned correctly.
• Secure the frame and apply insulation: Secure the frame by driving screws or nails through the frame into the studs, spacing them about 6 to 8 inches apart. Apply foam insulation around the frame to fill any gaps between the frame and the rough opening. Then, open and close the door a few times to ensure it swings appropriately and the frame stays square. 

Reattaching the door and finishing touches

If the door is not prehung, it’s time to reattach it once the door frame is securely in place. 

• Reattach the door: Align the hinges with the hinge plates on the frame. Check that the door swings open and closes smoothly before securing it with screws. If you can, get another person to hold the door steady while you attach the hinges. Once the door is in place, give it a final adjustment to ensure it’s level and fits properly within the frame.
• Install the hardware: Attach the door handle, latch, and locks and ensure they are centered and aligned correctly for ease of use. Tighten all screws securely to prevent any loose fittings over time.
• Caulk the trim: Next, apply caulk around the edges of the door frame where it meets the wall. This step seals any gaps for better insulation and a cleaner finish. Use a damp cloth or your finger to smooth out the caulk and wipe away any excess caulk.
• Seal any gaps: Finally, inspect the door and frame for any small gaps or imperfections that might have been overlooked. Touch up paint or finishes around the trim and door frame if necessary to create a polished final look.

How long does it take to replace a door frame?

Replacing a door frame typically takes a DIYer 1 to 2 hours. However, it can take longer depending on your experience level, the condition of the existing frame, the need for additional repairs to the rough opening, and whether you're replacing the frame alone or installing a prehung door.

How to install a new door frame

Changing your doorframe can restore smooth functionality to the door, enhance energy efficiency by sealing gaps, and increase security. Plus, it allows you to refresh your room's look, especially if you’re installing a new door that matches your style or adds to the home's aesthetics.

By following the detailed steps outlined in this article, replacing your door frame becomes a relatively easy DIY project that can save you money on labor costs. However, it's best to call a professional if the project involves complex issues like structural damage, improper framing, or replacing the entire door unit. A pro can ensure the job is done correctly and prevent potential mistakes.