@busso Hi Wilfred...I have thought that metal inside the lid is problematic (although often recommended on the Forum) because of metal sweating (complicated issue) and it is interesting to note your problems with water. I have used adhesive silicone only to seal my Flow roof and it is brilliant. Coupled with my seemingly unique Flow logo ventilation holes - no moisture problem.
@berrmich Hi Mike, well it seems I am the only one to have holes right through the logo. I am starting to think my flow roof is a rare and valuable item being so unique. Must be worth thousands! Perhaps the laser cutter was turned up too high? It is cut through as clean as a whistle by the way. They work a treat I must say. I've always marvelled at them and how they were cut just small enough to stop bees getting in and out and yet large enough for ventilation.
@Dee Hi Dee, I think from reading what Jack and Wilfred have said that there is moisture in the roof space although as you point out, where does it come from?. As you know there is moisture in the air to some extent everywhere and sealing up the top feeder hole from the hive won't mean there is no moisture in the air to condense on the metal or wood inside the roof. Further, moisture from the hive will travel thorough the inner cover even if it is sealed, as the timber is constantly taking in and releasing moisture, and water vapour will of course move through the wood of the inner cover from within the hive and end up in the roof space too. It is my belief that it is for these reasons that Wilfred and Jack have/have had moisture issues.