Sorry to bring this back from the dead. But it's the best discussion I've found on the topic and I've found no answers.
If Roxul is used as insulation, and a poly vapor barrier used, then what should be used on the outside of the house during a renovation? The job I'm looking at is removing 50yr old aluminum siding to expose homosote sheathing underneath. Depending on the condition of that I might replace the homosote with new sheathing. But I don't want to use a product like Tyvek Housewrap that would create a double vapor barrier.
Thanks. I also received this response from Roxul directly. The Tyvek should work fine.
The Tyvek house wrap that most builders are using is only an air barrier, it will not act as a vapor barrier the same way the plastic you installed on the inside did. The Tyvek will help control air flow and create a tighter building envelope. There is a number of air barrier products on the market and as long as they are just an air barrier there will be no problem using one.
If you have any other question please feel free to contact Roxul.