I have short (<12″) parapet walls surrounding a flat roof (house in zone 2A). The parapet walls are connected to the attic (I guess this would be termed ballon framed) which is conditioned. What is the best way of addressing the ventilation and weather barrier here:
1. Treat these short parapet walls as part of the conditioned attic and cover them with the TPO membrane that will be covering the rest of flat roof. I would also later plan on filling these with Rockwool batt insulation.
2. Separate these from the attic, cover them with breathable membrane and ventilate to the outside?
Approach #2 does not seem to be very practical given the short height of these walls but I want to be sure I will not be creating a condensation problem by covering over the top with TPO. Thank you.