What is the safest way to insulate our 3 story 110 year old wood framed clapboard/shingle Victorian house in the Northeast?
We don't want substances on which mold might grow and or those which prevent the house from breathing. Blown in fiberglass insulation (Atticat) was suggested, but it contains formaldehyde. Are other products safer for our health without being harbors for mold ? How important is it to block up cracks where the walls meet the floors, etc.?
Your safest way is to bring a professional in to evaluate whether you have any moisture issues, electrical problems (knob & tube / aluminum), etc... before you even try proceed / what it will take to proceed As for the house not being allowed to breathe, well by allowing it to you are just asking for mold issues as it is very important to seal up those air leakage paths as the biggest causes of moisture problems in the walls is not diffusion but rather air-leakage For more: http://blog.sls-construction.com/2013/building-science-house-needs-to-breathe