If you need a great indoor-outdoor carpet, then olefin may be the best option for you. The second-most common carpet in American homes, olefin, also known as polypropylene, is a stain-resistant, fade-resistant, moisture-resistant, and static-resistant colorfast synthetic carpet.
Olefin is often used for entryways. Because it is moisture-resistant and fade-resistant, olefin carpet is a good choice for porches and patios, and the moisture aspect also makes it a good choice for basements.
The static-resistance makes this a good selection for a room with computers.
Olefin is chemically inert and resists acid and bleach well, making it a good choice for laundry rooms and rooms with home aquariums, and for areas leading to or adjacent to swimming pools, such as changing rooms.
Olefin can be challenging to keep clean, because it attracts dirt. Even after drying, olefin tends to wick dirt from the base causing streaks and spots to reappear.
Olefin is very susceptible to heat, so much so that even dragging a piece of heavy furniture across olefin can leave scorch marks.
When choosing olefin, look for a carpet with loops. The loops can help avoid matting. Whether you choose loops or pile, look for a low carpet (loops or pile). This can help it resist crushing.
Olefin is generally the cheapest carpet available.
Trying to choose the right carpet? Read our entire series on Choosing Your Carpet.