We own a 114 year old home in New England, and it could really use some more insulation, Brrrr. Most of the walls in the house are wallpapered (some paneling) horse hair plaster. We had a contracter come to the house to take some measurements and talk to us about Blown In Insulation. One of the comments he made was that some of the plaster on the walls is soft. He told us that he reccomend filling the walls with low pressure to not disturb the plaster as much as possible. He also indicated that there's a possiblity that we could see bubbles in the walls or even cracks in some areas. Is this true, and in my case is Blown In Insulation the best course of action? Also, will using a lower pressure setting change the R-factor, or have a less insulating result?