To Foam or Not to Foam
We are in zone 5, central Illinois and have just purchased a large Victorian home with an unfinished attic. The attic is huge: 1800 sq. feet of ceiling and 600 sq. feet of walls in three of the four dormers (windows on all four sides). The floor is original boards and I've detected some regular old fiberglass insulation poking through in various places. There are currently vents in the sophists (although not as many as would be expected in such a large space), vents in both of the larger walls as well and three roof vents on only one side of the pair of largest roof angles. So lots of vents, none doing much.
We've had three insulators come out and now have three separate opinions on what to do. 1st man wants to spray closed cell foam over the whole space and seal it all up (old 2x4 rafters will only allow us a max of 3" of foam). My question to him was what do you do if you have a leak in your roof - it is undetectable because nothing comes through the closed cell foarm. His answer was that you need to have regular roof inspections. Not a great answer since my roof is now nearly four stories up (house was moved to current location and put on 8ft. foundation). Roof was done in 2004 by the way and looks to be the easy to install and cheaper versions of shingles).
2nd man wanted to just stuff as much rolled insulation as he could get in there and not do any venting and cover up our existing venting. his opinion was that we didn't need any vapor barrier, that because of the angles of the overwhelming amount of gables that most don't even reach to the overhang and aren't vented anyway.
3rd man wants to use Icynene open cell foam, which he says would allow water to come through but the product would dry and retain its integrity. I liked his approach the best, but am now reading about mold and wondering about the material holding water.
We'd really like to convert this great space into something useable, but are now more confused than ever.
Any insights into dos and don'ts would be much appreciated.
Heidi (Urbana, Illinois)