When i sided the house (vinyl siding) 8yrs ago i didn't find any pluged holes. I wrapped house and installed windows and siding. Put 12 more inchs in attic, now its time to do the walls thought i could drill two 2" holes as close to the top as possible one to blow insulation in the for relief of the pressure so it (pressure) don't blow the black board loose. The house is 33 yrs old insulation in walls is blown in type and it has setted over the yrs.Thought someone would have done this before.
Blown insulation will go through a 1" hole with a special hose on the end of the blowing hose. It is not necessary to drill another hole for relief. The supplier will usually loan the machine free when you buy the insulation and they can sell you plastic plugs that will not be too noticeable, especially if your siding is white.