I need to mount a Generac automatic transfer switch to my house beneath the meter base. The construction of the wall I need to mount to is (from outside inwards):
- 30 yr old vinyl siding (for which I cannot buy new siding to match)
- R7 foam-board, 3/4(?) thick (a regrettable decision in retrospect--wish I had used 5/8 plywood for all walls)
- 2x4s 16" o.c.
- 1/2" drywall
I think I have basically two options:
- cut and remove all material that'd be behind the automatic transfer switch, mount 1 or 2 layers of 3/4" plywood to studs on either side
- mount the plywood directly over the vinyl siding--making sure it is large enough to fasten to two (or more) studs. I would use long lag bolts and washers to ensure that they didn't pull thru the plywood. I estimate lags will be 3/8x3". The thing I dislike about this option is maintaining/painting the plywood and preventing the need to ever have to replace it.
Option 2 would be easiest and I am not convinced that Option 1 is sufficiently more structurally sound than option 2. Is it worth the risk of damaging the irreplaceable siding?
Are there better options I have not considered?
and are there any electrical related concerns (with either approach)?
The wall is east-facing and sees little direct precipitation although lots of direct sun.