Sorry you are still having trouble with this part. Here is a post from the developer about how to pick up that ladder:
The first ladder you need is the long ladder, which is in the 'terminus' building that you unlock with the key that comes in the post. To pick it up, you must first have seen a need for it. Go round to the right hand side of the house and look for an 'up' arrow as you walk towards the back of the house. It's around the halfway point when you are under the scaffolding. You may have to move your cursor around the screen to find it but when you do, click on it to look up. At that point you should see a cog cursor where a ladder would be useful. Now go back and pick up the ladder.
Let us know if this helps.