I have a regular langstroth hive and I have two wonderful mentors. I am newer to beekeeping and just purchased a flowhive. I will be getting my nuc at the end of the month. On my langstroth hive, I have a quilt board with pine shavings for the winter (to help with moisture) and in the spring/summer I switch it to a screen board to help with ventilation.
Do flowhive owners use a screen board to help with ventilation?
I am going to do a potentially infuriating thing, and not answer your question directly… Sorry! 
Whatever you are doing for your traditional Langstroth should work great for your Flow hive. The only difference is the harvesting method. If you are successful with what you are already doing, keep the methods the same. It simplifies things! 
Now to answer a little more directly, most beekeepers that I have interacted with (across a large variety of climates) do not use ventilation boards, except for during transport in hot weather. My esteemed friend @JeffH will direct you to the video on YouTube called “City of Bees”, which shows how bees use the closed space of the hive to set up a laminar flow ventilation system to act as natural air-conditioning. If you put a ventilated roof or floor into such a system, you will disrupt the laminar flow. If you are comfortable and successful with a different method, by all means try it, especially if your mentors think it is good for your climate.
Hope that helps!
Thank you for your reply. I was curious with the pitched roof if that offers more ventilation or adding a screen over the top board that came with the flow.
I am still learning, so I appreciate all information. I will check out the City of Bees. Thank you!
What screen board came with the Flow hive? I’m familiar with the QE, as well as the ss slatted sheet that sits on the bottom board.
If it’s the one that comes with the Chinese copy, I suggest to people to cut the wire & center board out, leaving the outside frame, Then I suggest to glue that frame under the roof, so that the roof doesn’t interfere with harvesting the honey. Then I suggest to use a hive mat, as well as block those large holes in the roof… I have no idea why they make them like that.
A hive mat can be a piece of vinyl, or plastic that sits over the frames, however leaving a bee space all around it, so that bees can enter the roof cavity from either side, or end. One bonus of that method is that bees will propolise the roof down to the honey super, meaning that there’s no need to tie the roof down, in case of high winds.
I like bees to have access to the roof, which acts as a pressure valve, for when the population explodes. For this reason, I try to encourage people to lift the roof once a fortnight, especially when populations are building. That also allows folks to act quickly when bees start building comb in the roof.-
A screen board didn’t come with the hive.
My is authentic Flow Hive.
Well done Christy 
You never know, my advice might be useful for anyone with a fake flow hive.
I sold bees to a bloke with a fake 3 weeks ago. I gave him this advice. I’m hoping he follows it, because even in our sub-tropical climate, the bees will get awfully cold with those large holes in the rood, with winter just around the corner.