We bought a 10 year old house sided with vertical cedar boards. We have a 12+ feet wide sliding glass door out to the deck (consisting of 2 sliding center panels and two fixed end panels).

I bought a 13 foot wide retractable awning that I plan to install with the help of a few friends. As obvious as it may sound to do I am looking for help locating the header and studs so I can screw the brackets into them, instead of into just the siding. I have not been able to find the header and studs using a stud finder.

My assumption is that there is at least a 5.5" wide (tall) header over the door, that extends at least 1.5 or 3 inches beyond it on each side. I can install the two mounting brackets anywhere along the length of the awning, so my thought is to mount them as far apart as possible, but still over the door�s rough opening, and just a few inches above the door itself.

Can I just assume there�s a header where I�m planning on screwing in the brackets and just go forward with my plan? Any suggestions for locating the header before I start drilling holes and bolting down bolts?

Thanks in advance.