In this picture you see a 2 x 4 cut with two angles on the end of it.
These blocks are there for a very good reason, if there is a fire
underneath the set of stairs these blocks will prevent oxygen from
getting to the fire in flames from going in between and through the
Fire blocking gives you limited protection in case there is a fire. A 2 x 4 has a one-hour fire rating, which means that there is a fire it could take up to one-hour to burn through an inch and a half piece of wood. The main reason for fire blocking is to give the fire department more time to put out the fire. These blocks or very important in costs little to put in the could save the lives of people you love.