Stair rendering

Put the summary of the bug you're having here

What I expected to happen was...:
I walk away to admire my house and the roof made of stair blocks would be solid

What actually happened was...:
The stair blocks flickered as I moved and in some places I could see through them

Steps to Reproduce:
1. Place multiple stair blocks next to each other
2. Walk away from the stair blocks while watching them
3. At a moderately far distance the stairs will flicker and parts will disappear.