Carpet in a house is rarely one single piece. More often it is made of several strips that are spliced together. When done properly the splice lines are invisible, creating the illusion of a solid carpet surface. Splicing two pieces of carpet is accomplished with the use of a seaming iron and seaming tape. Both of these items are available at your local hardware store. If you have never spliced carpet before, practice on a few remnants first.
Line up the two pieces of carpet. If the edges are not perfectly straight, overlap one on top of the other slightly. Use a sharp knife to trim the edge of the lower piece, using the edge of the upper piece as a guide.
Lay a strip of hot-melt seaming tape under the seam created by the two pieces of carpet. The seam should run down the middle of the tape.
Turn on the seaming iron and give it time to heat.
Hold the sections of carpet open and press the iron against the tape at the beginning of the seam. Let it sit for 30 seconds.
Begin sliding the iron slowly forward, heating the tape as you go. Have a second person press the two pieces of carpet together into the hot tape behind the iron, creating as tight a joint as possible.
Continue ironing the tape and splicing the carpet until the seam is complete.
Sew the two halves together using a curved needle and fishing line if the splice is in a particularly high-traffic area. Keep the stitches as small as possible to prevent them from being noticed.
Roll a carpet tractor over the seam to blend the carpet from both sides together.