Smoke conditions on your arrival at an attached garage fire will tell you a lot about interior door positions. Excessive smoke in the home indicates an open door between the garage and home. Little to no smoke in the building says the door is closed. Sounds simple! However, it's what you do with this information that makes a difference to firefighters and the homeowner.
With fire in an attached garage and no smoke in the home, crews should attack the fire through the garage. Whether that's through an exterior door, a window opening, or the main garage doors is a tactical decision the officer needs to make. Lines into the home to assess conditions and control the interior door should be deployed as well, but the interior door should remain shut until the fire is knocked down in the garage and toxic gases aren't going to enter the home.
With fire in an attached garage and smoke in the home, crews should attack the fire through the garage. What? That's what I said above? YES! The difference is that your crew that takes a line into the house to assess conditions should primarily be tasked with closing the interior door. Be aware though, that these crews are directly in a flow path that can bring heat, smoke, and steam down on them from the garage attack.
Does this work in evey situation - no! Am I saying this is the only thing that can be done - no! Am I saying that reading smoke conditions and applying fast water is good - YES!
Remember, we are there to stop and limit damage to the home and its occupants. Don't open interior doors to attached garages in the name of "attacking from the unburned side." All it does is allow smoke and toxic gases to enter a relatively "clean" home and do more damage.