Please tell me what is wrong with my plan (or what would you do)
Our house has 2/12 to 3/12 pitch shingled poorly insulated roof (leaking around chimneys and skylight) that we decided to change and built higher pitch roof on top of existing structure.
Part of the roof (25 by 60 ft.) has a regular framing with plywood decking and soffits/vents.
Another part (2535) is 26 tongue and groove decking with inch old insulation board (that is going away) and shingles nailed straight through it.
We don’t want to change anything (or much) inside the house and we are going to build new framing on top of existing roof. My biggest questions are regarding T&G part of house - right now there is no ventillation - we will probably install 6-8 inches of foam insulation right on top of T&G and have vents/soffits installed.
Does this whole plan makes sense ? How much you think it might end up costing me ?
Thanks in advance.