How deep do you kerf a door jam?

When kerfing a door jamb, the cut should typically be about 1/8 to 1/4 inch deep. This depth allows for the proper fit of weather stripping or other sealing materials without compromising the structural integrity of the jamb. It's essential to ensure the kerf is straight and even for optimal results. Always check the specific requirements of the weather stripping being used for best fit.