Ever heard about the rotten door jamb? When the exterior of your door frame suffers a variety of environmental factors, such as rain, heavy winds, ice, and snow, the lower part of door frame becomes rotted. It starts looking weird and ugly. The rotten door jamb also lowers the beauty of the house. Commonly the door frames rot at the bottom corner where it meets the door sill. There are some ways by which the rotten door jambs can be repaired very easily. Any person with little skill and a handful of tools can do this repair.

1.  Repair Vs. replace

If you have had any kind of entry door with wood jambs for more than a few years, chances are there that the lower portions of the jambs are a bit unsightly and on their way to causing you some problems. The most confusing situation is to decide whether you should repair your rotten door or simply replace it with the help of a professional. The final decision should be made on the signs that occur on the rooted door jambs.

You need to Repair the rotted portion if…

  1. You prod the area with a screwdriver and the wood is soft but intact.
  2. You’ve noticed some dark spots on the door jamb
  3. You see some damage, clearly contained to one area

You need to replace the full rotten jamb if

  1. The mold has visibly spread through the door jamb, causing it to bend or crumble.
  2. The damage has spread beyond the door frame into the surrounding structure of your house.

2. Tools required to repair the rotted jamb

Replacing the door frame is easy. All you need to contact a professional to replace it with the new door frame. But when it comes to repairing the rotten door jamb. There are two ways to do it. One is simply using the paint and filler to cover up the rotten area of the wood.

The second way is to replace the rotted area of the door jamb with a new piece of wood. Both are used widely by the professionals to repair the rotten jamb.

First method: This method is less time consuming and easy. All you need some tools and products that are easily accessible at the local market. You may need

  1. Paintbrush
  2. Putty knife
  3. Rasp
  4. Sanding block
  5. Utility knife
  6. Wood chisel
  7. 100-grit sandpaper
  8. Polyester filler
  9. Wood hardener

Steps to repair the rotten wood:

  1. Remove the most affected part of the door jamb with the use of a putty knife.
  2. Apply wooden hardener on the rotted door frame area.
  3. Also, use polyester wood filler or Bondo wood filler and press it into the recess with a putty knife.
  4. Carve the partially hardened sagging Bondo wood filler with a putty knife or chisel.
  5. Add another layer of filler if necessary to the rotted door frame.
  6. Paint it with a similar color to the door. Done!

Second Method : This method is time-consuming and need some extra care and expertise while performing. You can try to do this on your own but we recommend contacting a professional to do this. Tools you may need

  1. Measurement scale and marker pen (To measure the affected area of the door jamb)
  2. Wood (To replace with rotten door jamb)
  3. Wood filler (To fill the hollow places)
  4. A cutter to cut the affected area of the door jamb
  5. Wood glue (To stick the new wood with old one)
  6. Paint (To give finishing)

Steps to repair:

  1. Measurement: Take a marker and scale and mark the affected area of the door jamb. Mark a horizontal line on the door jamb using the square at a location several inches above the rotted area. Do not mark the part that is not rotten.
  2. Cutting the portion: After marking the rotten area. The next step is to take the portion out by cutting it. This step needs extra care. Take a cutting machine and cut the door jamb from the marker. Make several straight-in plunge cuts along the marker line. After this, use a wood chisel (like a flat-head screwdriver) to take the rotten wood out. You can also use a flat head screwdriver and hammer to split jamb into sections and pulled out the pieces.
  3. Replacement: The next step is to install the new jamb splice. For doing this you must have a new piece of wood that will be replaced with the rotten one. After pulling rotten jamb piece out. Cut the new wood in a similar shape and size that can easily fit in the place. Apply the wood glue on the backside of replacement wood and stick it in the hollow place. After 30 minutes the replaced wood will stick with the door frame permanently.
  4. Wood filler: Wait! The process is not done yet. Even after replacement, there will be some hollow spaces that need to fill out. You have to use a wood filler for this purpose. Remember that Wood filler isn’t designed to fill large and deep voids. So, place the replacement wood very carefully so that less space will be left.
  5. Finishing: The old jamb becomes rotted when the caulk seam fails. It’s important to use a high-quality exterior silicone caulk that stays flexible year after year. So, Caulk the seam between the sill and jamb. Also, caulk the along the bottom end of the brick mould. After securely installing the replacement wood, sand the seam formed by the replacement piece, to create a smooth, seamless unit. Once you’ve repaired the door jamb, paint it with matching door frame colour.


Repairing the rotten door jamb is possible but If you leave any mold in the area, you’ll soon have another case of wood rot. If you suspect the damage is too severe to remove all traces of mold, contact an expert, as you may need to replace the complete door jamb. But it’s best to prevent damage to your exterior door jamb than repairing and replacing it again and again. You can stop the wood rot by waterproofing and sealing your door frames. Please visit MCL Flooring for more articles on wooden floors, wooden floor repair and wooden doors