Ventilation should be above their heads not below the roost.The sides rolling up allows fresh air but heat and ammonia will still rise to the top and can't escape.
Chickens need air movement & exchange (circulation & ventilation) as well as shelter from the wind ,rain and snow. Providing one and not the other can be deadly.That black tarps going to absorb heat and cause them to overheat on sunny days.Set a temperature gauge on the wall and get an app that...