If you're unable to climb up to the top of ladders without just falling back down to the bottom, like seen here, here's how you can fix it.
Image References
In the images below, blue is your clip / ground you're trying to climb over, green is the ladder brush, and red is a wall_climb brush
Description
You want your ladder clip to end level with the floor, and clip into the floor some. Then, add a wall_climb brush 1 unit above the floor, and clipping 1 unit into the ladder, aproximately 4 units tall and 4 units wide.