Stretch-in vs. Glue-down
Stretch-in carpet installation is the most popular installation method in homes. In this installation, strips of wood (called tack strip) are nailed (or sometimes glued) to the floor around the edges of the room. These strips have hundreds of nails that are angled in towards the wall. Padding is secured to the floor in the middle of the room. The carpet is then attached to the pins around the room. The installer then stretches the carpet tight across the room.
Glue-down installation is the most popular carpet installation in commercial settings. In this type of installation, the carpet is glued directly to the floor. The floor needs to be very smooth. Any imperfections in the floor will telegraph through the carpet and be visible. Imperfections in the floor may also cause wear spots.