Greenhouse Roof Vents?

[GreenhouseGoblin]

can u show us your greenhouse ??

i dont use roof vents (mine just a hoop house from cattle panels ) just open up both sides and the ends in the summer with fans moving air in the winter try to hold heat in as needed
building some frames for exhaust fans should be farily easy

Here is a stock photo of my greenhouse. I'm still out if town, so I can't get you photos of my actual one.

 

[Oliver Buckle]

Here is a stock photo of my greenhouse. I'm still out if town, so I can't get you photos of my actual one.

Don't think that worked, no photo visible here.

 

[GreenhouseGoblin]

Don't think that worked, no photo visible here.

 

[Oliver Buckle]

I would make something crude and simple, cut a hole in a the pane, find a piece of plastic a little larger than the hole so that if it was placed against the inside it would cover it, make a small hole either side of the centre and cut a piece of strip wood the length of the cover with holes that matched those in the cover and a piece a bit longer than the width of the pane. Two screws would go through the piece of wood and the cover on the inside and into the longer piece on the outside, the outside piece would rest on the aluminium frame. Do the screws up and the cover would be pulled tight against the frame and the pane, undo them a little and you could slide the cover down leaving a gap, then tighten them enough to hold it in place. The gap would only be half the size of the hole as the screws would come up against the bottom edge, but if it is at the top hot air is not so dense and rises so you shouldn't need too much of a gap.
I did say it was a bit crude, and you would need a screw driver handy to open and close it, but it is, as I also said, simple. A drill, a hacksaw blade (Tape one end to hold it) and a screw driver for tools, two pieces of strip wood, two screws and a piece of plastic sheet for materials.
I can't see what the inside frame is like, but I suppose you could equally make it with the long piece inside and the cover outside, Two screws will stop the outside piece spinning off the horizontal when you do up the inside one.

 

[delightfulbags]

Hello all and thanks for letting me join!

I built my first greenhouse last year and used it with some mediocre success, now that it's almost January I would like to start plants.

I came here because last year I determined that part of the reason I wasn't very successful was because of my ventilation.
My greenhouse plans didn't call for any roof ventilation, only the windows on the side. This wasn't a problem when it was warmer out, but if it was colder outside, say around 28°F and sunny and I needed to open the windows, I ran into frostbite problems on the plants in front of the windows that opened.

I think I would have had better luck if I had had roof vents to allow the warm air to escape through the roof.

Now, as I mentioned above my plan didn't come with any roof ventilation, the entire roof - except for my propane heater exhaust - is covered in ribbed wall polycarbonate.
So, my question is: are there any easy ways to install roof vents in a greenhouse that didn't come with them?
I don't care if I have to remove polycarbonate panels or cut them, I'm just looking for a solution that doesn't require me building a new greenhouse roofers utah.

I'm also open to making roof vents, if someone can provide me with good instructions or plans.

You can install pre-made roof vent kits, cut and frame a DIY vent with hinges, or add louvered vents near the peak. Use an automatic vent opener for hands-free temperature control. Seal edges with weatherproofing tape or silicone after cutting the polycarbonate.