Rockwool Comfortboard vs. ZIP-R
I’m in the process of re-sheathing the house in central Texas because my brick has only painted OSB behind it (no tar paper or house wrap) and as you can imagine the mortar bridges have caused water damage to the sheathing. Since I’m removing the brick I have the option of adding several inches of continuous exterior insulation and using a thinner rain screen such as Nichiha fiber cement. I’m trying to decide between ZIP with Rockwool Comfortboard and ZIP-R or possibly insulated MgO panels. The ZIP+Comfortboard combo should allow the exterior of the sheathing to dry to the outside but I’m concerned it could cause condensation on the exterior of the sheathing in the summer months. On the other hand, ZIP-R only goes up to 2.5″ so I might still have to do exterior insulation anyway. Matt Risinger put exterior polyiso insulation on his house which maybe is the right option for me too, but couldn’t it trap water between the insulation and sheathing?
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