[David70]

I purchased the house next door to ours about 9 months ago, complete gut, now at point of completing plumbing/electric rough in. Got a package deal on roofing both houses are being done now. We live in an urban area where houses are close together and lots are small (houses from 1910's), so bought the house next door, plan to rent it out, then build a two car garage on this property but keep it for myself. Have 1 car at our house so total of 3 spots.

Once electric/plumbing are done and inspected, with roof done I will be dealing with insulation. Want good insulation but with it being a rental there's a limit to what makes sense. Had planned on doing spray insulation on 3rd floor walls and underside of roof. One company said they would only use open cell as it is water permeable, if there's a roof leak it will come through the insulation and show on the drywall. Negative is open cell isn't as good of an insulator. Other contractor only would use closed cell because of R value and said roof shouldn't leak, correct but it could and if it does the water will take an extremely long time to get through the lumber, likely with a lot of wood damage.

Any thoughts?