Many carpets are installed without using tacks. When installing carpets this way, carpet layers first fasten a tackless strip to the floor, next to the wall. Then they install the padded cushion. Next, carpet installers roll out, measure, mark, and cut the carpet. They purposely cut the carpet a little big.
Carpet layers position the carpet and stretch it evenly over the floor and to the walls.
Once the carpet is stretched, they cut off the extra few inches of material. Finally, carpet layers use a power stretcher to stretch the carpet a bit more. They hook the carpet to the tackless strip that holds the carpet in place. Installers give the carpet a final trim around the edges with a wall trimmer. Floor layers use a similar process when laying linoleum.