I have 30 year old batted fiberglass insulation between the joists of my unfinished basement floor. Rodents come in from the exterior and take up residence in the not so lovely fluffy stuff. It is falling and full of rat @#!. I have removed it, am attemting to put hardware cloth around entry points, etc. NOW, to replace the insulation I started with rigid polystyrene foam which is a pain to install, AND and figured out is VERY flamible. My guess is that it would not meet code. I just did one line of it before I woke up. I do not want to put the fiberglass insulation back because of the rats, although this seems to be industry standard . Question: Is the spray foam option a good one, and is it also very flamible? ALSO, I've seen kits on the internet, but am nervous about trying it because it is still pretty expensive. I HATE rats
. Any thoughts?