Fire blocks are pieces of wood or foam used between studs to help block fire from spreading through a house. Many people wonder why plain wood would be used as fire blocks if it is flammable.
Before fire blocks were required, you could drop something from a hole in an attic wall all the way to the basement. If a fire starts, the channels made by studs act like huge chimneys that allow fire to travel from one floor to all of the others. The fire blocks help block the path of the fire before it can spread.
Fire blocks need to be installed between all of the studs in your home. Longer versions must be installed between each level and in front of the gaps where the flooring is so fire can't travel horizontally across the floor.
Materials for Fire Blocks
Most fire blocks are made from a cheap material like wood or foam. Be sure to check that you are using fire resistant foam before purchasing it. For extra protection, fire resistant caulking can be used to fill in gaps and holes. The current standard grade of fire resistant caulking is colored red so inspectors know you used the right stuff.