Ice and watershield products are a vapor barrier they do not breathe.
Metal roof installed over battens.
Basically all metal roofs that can be installed on battens can also be installed on solid decking with underlayment.
There are several things to consider when determining whether or not to have your new metal roof installed over battens.
By design some metal roofs must be installed over battens some must never be installed over battens and some can be installed over battens or over solid decking.
By design some metal roofs must be installed over battens some must never be installed over battens and some can be installed over battens or solid decking.