Using the flame bomb when Barik raise his shield is a good way to make him retreat as the flames will go through the shield and damage the enemies who are closed.

If Barik is hugging his Turrets, use fire bomb. The turrets cannot be moved once deployed, so he will likely abandon them if fire bomb lands on or near them.

Tyra can throw her Fire Bomb through Barricade. You can punish an early Barricade this way.

Try to avoid the fire bombs, as they can do large amounts of damage to your Barricade and your Turrets.