Decks, Patios, Porches and Docks - Finding Ceiling Joist Behind Vinyl Siding on Porch

I bought a hammock style chair that hangs from one hook, similar to a porch swing. I am having trouble locating a joist to place the lag screw style eye hook that I purchased to hang it. My house is 2 story, built in 2004. Would the joists be in the same place on the porch as they are in the house on the first floor? There is vinyl siding over the ceiling on the porch. I have tried a stud finder outside, but am having no luck with that, I am assuming due to all the "bulk" created by the vinyl. Any suggestions would be appreciated

Welcome to the forums! If you push up on the soffiting, you should feel the joist as opposed to it being loose. Does your stud finder have a deep scan mode? That may pick it up better. Be sure to hit the joist dead center with your hook, as any thing else would be a weak spot.
I prefer to remove portions of the soffiting and install a spanner across and between the preferred joist to hook in the swing.

I don't know if it applies but around here the porch ceilings are often on 2' centers so the vinyl guys will install 1x strapping on 16" centers, perpindicular to the rafters. The strappiing isn't stout enough to support that kind of load. I agree with Chandler that removing a section of the vinyl and installing solid support is best.

Hey chandler... you're just up the road from me... I'm in Blue Ridge lol... you could just come and install it for me lol

Larry is right on -- remove a little vinyl and install your own blocking to support the chair. That will allow you to locate it exactly wher you want it, and it'll be stronger. You can through bolt an eye bolt thru the blocking and hook the chair on that.