I'm going to make a support beam for the porch. The problem is that the beam under the door is rotten, not completely but a bit in before you reach solid wood. The size is about 170x120 mm. My first thought was to remove it completely and replace it with something similar. I found construction lumber with similar dimensions Or could it still be usable? I also came across "epoxy filler" (see link) which seems interesting when I read about it, would it be possible to use it? Or are there any other smart solutions?