I have removed the old ceiling down to the lath with the intent to install painted pine t&g. The room attaches to the back of a 1922 Dutch Col. and has a hip roof. There seems to be some type of blown in insulation so I am reluctant to remove the lath; however, I would like to increase the R Value by using some type of rigid foam or should I just bite the bullet and rip it all down and install rolled fiberglass and if so should I use a vapor barrier?
Since it's that old, I would remove everything to the framing. This would give you a chance to inspect the roof deck, before you re-do it.
Thanks DJ for replying to my post. What I failed to mention was the previous owner installed a new roof last summer and the flashing was not installed properly, that has since been corrected. Hence, the tear down of the existing ceiling.