Stud finders... I prefer the $2 ones. Mainly because here in my home town, I find many houses in the fifty or so year old range have GB that varies from 5/8 to 9/8. Yup, that's what I said. One inch was made for industrial use firewalls and it can be up to 9/8. The modern stud finders won't work. And, if you can "knock out" the studs at that thickness, you are a young pup without hearing damage from power tools. Then again, I suppose some of you would hang a dozer on that kinda board.

Of course, I can often circumvent the problem by using a non-destructive moisture meter. But, they cost about $250 for a decent one. Not yer happy weekender special.