Grant,
I still have a 13′ x x12′ roll of roof observatory with such a roof. I used well painted hardboard sheets nailed to timber for the walls. It’s still standing and was used for over 20 years and fell into some disrepair as a result of long standing serious illness.
I did find that during the summer the interior got very warm and equipment took some time to cool down. Condensation was never a problem.
I now have 2.7 metre dome on top of a wooden construction for which the dome and metal work (including telescope) suffer from condensation for which I use de-humidifiers that solve the problem.
Regards,
Eric