I own a 1952, slate roof, cape cod in MD with No attic insulation. I am looking to finish this blank canvas into two bedrooms and a bath(in the future). I really like the slate but know that it will need to be replaced in the near future. I am trying to get another several years out of it and will use synthetic slate to replace.
The types of foams I am looking at are closed-cell and open-cell. Do I want closed cell to prevent water leaks? Or do I want open-cell? I have talked to several insulation guys and have gotten different opinions. Plus, I have investigated online "do-it-yourself" kits that I am considering.
Bottom line is anything is better than nothing. Just want to use the best product for my situation at the most cost effective price. Thanks for reading. Any thoughts would be appreciated!
(R35 is the recommended level for my area.)