what am I missing here, sounds so simple yet so hard haha. when putting up some cement plank you need to nail it to the stud, how do i find the stud if the sheathing is covered in a vapor barrier? my house is 70 years old so the studs are not at predictable spacings.
maybe I need to make some measurments of each stud and make some marks after I put up the tar paper?
First, where are you, and where in the house are you installing the cement boards? Are vapor barriers required by code in your area? They are generally being abandoned in most places on earth. Now is the time to remove it if you don't have to have it (by code) and air seal instead. If you ever run air conditioning, the vb can be disastrous. Finding studs w/out nails won't be fun w/out an electronic stud finder.