why will iPad not find home wifi network but works on others?

my iPad2 has a hard time locating our wifi network at home. about once a day it will find it and connect but only for an hour or so. its not like I'm getting a "can't connect error", it just doesn't see the network. it seems to have no problem connecting to networks outside the house (coffee shops etc). also all of our other devices have no problem connecting to the wifi. please help