Installing a weave is a process that requires a bit more labour. They're usually installed by a hairstylist who braids the hair down into a specific pattern — either what's known as a beehive or straight-back cornrows — before sewing bundles or "tracks" down to the braids. This can usually take anywhere from two to six hours, depending on how many bundles you're installing (two or three is a good amount) and how speedy your stylist is.
Weaves can last anywhere from six to 10 weeks, though it's important for people who wear them to also make sure they're still regularly taking care of their hair that's beneath the weave.