How to avoid soft bottom of home-made bread? The bottom of my bread is not hard. When I knock the top of the loaf, it gives a beautiful hollow knock sound but when knocking the bottom part -- it's not. I wonder what is the reason? How could I improve my baking procedure?


Bread baked in a baking tray with baking paper. Maybe it is the baking tray that blocks the heat supply?
~450F for 15 minutes, with top and bottom heaters turned on and a fan turned off,  then ~420F for 30 minutes;  all the time with baking tray sitting in the middle of the oven; the original recipe requires some 15F more but that's beyond my oven capabilities. I did not want to extend the time too much, because the top of the bread is already well-baked.
At the bottom of the oven I keep an ovenproof dish with water to increase evaporation. Maybe it limits the heat flow from the heater to the bottom of the bread?


In the first photo you can see a corner of bread. The left side is better baked, has larger "holes" in the crumb than the right side, because the left side was closer to the crust, and the right side was cut in the middle of the bread.
The bottom of your bread looks a little underbaked, by maybe 5-10 minutes. You can see that the crumb is tighter A few tips:


There is no need to keep the dish with water in the oven past the point where the crust of the bread is set. It is possible that water vapour from the dish interferes with the bottom of the bread cooking. Try taking out the water when you drop the temperature of the oven.
Times in bread recipes are a guideline, not a rule. If your bread comes out (a little) underbaked, put it back in the oven and/or adjust your cooking time next try. When you put the bread back in, you can also put it in upside down to encourage the bottom of the bread cooking properly.
To encourage the bottom of the bread cooking, you can use a pizza stone/steel, or even a baking tray. Leave it in the oven while preheating, then put the tray with the bread on top.