How It Shrinks
According to Floor Covering Installer magazine, linoleum expands in width and shrinks in length when installed.
Why It Shrinks
Excess moisture can cause linoleum, which is porous, to expand and dry heat can cause it to shrink if the flooring isn't sealed. When it is installed, the adhesive applied to bond it to the subfloor causes it to shrink in length and expand in width.
Cleaning
Harsh cleaning chemicals can damage linoleum and cause it to shrink and crack. Linoleum should be cleaned with natural products and those cleaning agents recommended by the product's manufacturer.