My wife and I are beginning to bring my parent’s late 1800’s vintage farm house back to life. We are planning to dense-pack celluose insulation into the uninsulated upsrtairs walls and do the same downstairs, where insulation ranges from none to some fiberglass and balsam wool (?) in various walls. The contractor will also be insulating attic spaces as part of this project. Being a retro-fit project, much of the home will not have a vapor barrier.

The siding contractor plans to wrap the house with 1/4″ fanfold foam before installing foam-backed lap vinyl siding over the foam. No building wrap (Tyvek) will be used.

I have installed shallow weeping tiles around the home and am piping the downspouts underground away from the house, as well as tightening up the field stone basement walls to eliminate moisture problems that have been part of this home’s seasonal life.

The house will be used mostly during the spring, summer and fall by my wife and I, with not much use during the winter months. The heat will be maintained during the winter months in the 50’s in the downstairs living area with the unheated upstairs bedrooms remaining unheated, at least for now.

I have been told by many that the dense-pack method will cause our house to “sweat” both downstairs and upstairs. Although I have read a lot lately in an effort to learn if we are heading towards a problem here I don’t understand the whole insulation, condensation and vapor barrier relationship well enough to know where I stand.

Can anyone help me out here?

Thanks