it's hard to see from these photos but even after some light rain the underneath of my vergola is drenched and dripping with condensation. They are sealed properly this isn't a leaking issue it's a condensation issue. 3 sides of this area are open so I'm not sure how much more ventilated I can get. Is there any reccomendation such as a spray to reduce the condensation?
Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about your vergola's condensation issue.
I'm sorry but your photos did not appear in the post. Can you please repost the photos? This will give our members a chance to assess the pergola. We can then make recommendations on how to proceed.
Condensation occurs when humid air, carrying moisture, comes into contact with a cold surface. When it comes to metal roofs, this phenomenon takes place when the warm, moisture-laden air from inside the house enters the space beneath the roof and becomes trapped there. As the temperature of the metal roof decreases during the night, the moisture in the air condenses and forms droplets on the underside of the roof.
In your situation it might be that the steel roof has gotten cold, and that warm moist air is passing through the gaps and running over the cold steel causing condensation to occur.
I propose having a look at the Suntuf Black Corrugated Foam Infill to block any air from entering the side area near the roof. One other possible option is to install a Bradford CSR 250mm TurboBeam Natural Roof Vent - Clear so that no hot air gets trapped under the steel.
If you need a hand posting the photos, please let me know.
Contact the people who made it / installed it. As EricL pointed out, the photos didn't make it to your post. I had to look up what a vergola is - airflow is the cure for inhibiting condensation & mould. Maybe the slats need to be left open a bit to allow condensation to evaporate?