What is the purpose of the dark fibrous material installed between the slab and the foundation?
a. It is installed to absorb slab expansion by compressing.
b. It is a control joint installed to control the locations of slab cracking.
c. It is an expansion joint designed to expand as the slab cures and shrinks due to loss of water.
d. It is a sponge-like fiber installed to allow water to drain from the slab surface, common in garages in regions that may receive heavy snow (brought into the garage on vehicles).