How to make a ladder

A ladder is made up of 2 brushes both of which are entities. First of all, you need to make a brush resembling a ladder.
 

   Make a brush which is at least 4 units thick and 128 units high. Now make a copy of the ladder and paste it somewhere. Select the first ladder and texture it with the blue texture. Now apply the ladder texture on both the sides of the brush. Now convert it to a func_wall entity and set the fx mode to solid. Also make sure the fx amount is 255. It should look like this:


The blue colour in the texture indicates alpha. I will explain more on this type of alpha value later.

    Now select the second brush and turn it into a func_ladder entity. You can put any texture you want to but the aaatrigger texture is recommended for brush based entities. Now just overlap the 2 entities over each other group them. That's it. You can now also make any type of a brush a ladder. Just make a copy of the brush and turn it into a func_ladder and you are good to go.