conduitelectrical-panelstuds
I'm changing the location of the electrical service mast on my house. Is there an easy way(s) or a trick of the trade to find a stud from the exterior of the house so my lag bolts that will hold the mast brackets will hit framing and not just rough siding?
Right now, my house is sided with vinyl over 1" of styrofoam, cedar clapboard and 1×6 board siding.
I have access to the interior side of the wall, too, but I'm having difficulty translating the stud location to the exterior.
If you have a wall, you have structure.
If your wall is masonry then the TV mount can likely be mounted directly to the masonry (or mounts are available which can).
If your wall is drywall then you must have structure behind it... perhaps your studfinder is malfunctioning or you're using it improperly?
Studs can usually be found beside original electrical boxes (as the boxes are mounted to the side of the stud). Check your stud-finder against both sides of a nearby electrical socket for functionality. If you cannot locate a stud, try tapping a small nail into the wall board near an existing fixture. If it meets resistance behind the wall-board then you have a stud. Wall studs should be spaced in regular intervals (usually 16" on center in the US) so you can simply measure over to your mount area to locate them.
Once you believe you have found studs simple repeat the above test: tap in a small nail to verify structure behind the wall board. Studs should be 1.5 inches wide, so check that you can mark both sides of the side (to mount into the middle).
You may need to tap many small holes to accomplish this without an adequate stud finder.
Maybe there was a drywall patch and this is a back brace?
From your description, it appears that trimming this piece will do no harm (and a lot of good).
The easiest method is to use a multitool.
There are numerous good brands, and they come with a variety of blades and other attachments.
These versatile tools make cutting, sanding grinding in tight spaces much easier. They vibrate their blades and other attachments very rapidly in short strokes from side to side. If you buy one, you will be surprised how often is it the easiest way to do a job (e.g., trimming the bottom of door jambs to insert engineered floor boards).
Best Answer
Plan A
Find an interior:exterior reference point... a window, electrical penetration, etc. on the wall in question.
Using a studfinder, or by examining baseboard nails and outlet locations, find a stud from the interior. You can often knock with your knuckles and determine to which side of an outlet the stud lies.
Measure from the stud to your reference point. If it's a window, measure to clear glass.
Outside, measure back from the same point.
Plan B
No "exploratory holes" through your siding or wounds in your drywall are needed whatsoever here.