How to install Bastion roof vent on shed?

[Ask_Itee]

I have a large garden shed that needs a roof vent.  I purchased a bastion roof vent https://www.bunnings.com.au/bastion-300mm-aluminium-mill-roof-vent_p0810899 and found there is no guidance on installation method in the box, their website - anywhere.

The garden shed 4m x 4m and too light a construction to get onto the roof to complete the install.  I can see other brands suggest installing under the ridge capping, but I can see its too risky because of the light roof construction.  The pitch is much less than shown in the di.agram below

What is the recommended method?

regarding instruction, I was surprised not to find something -  I'd understand if I purchased it on Temu, not Bunnnings.

[MitchellMc]

Hi @Ask_Itee,

I've confirmed with one of our stores that there should be an instruction sheet in those units. It's inside the plastic bag, which contains the vent, and up inside it. If you can take another look for me, and if it's missing, I'll get you a copy. In the interim, here's a copy of the installation instructions for a very similar product. They are all typically installed in the same manner.

You're correct that on a corrugated steel roof, the vent must be installed with its top edge under the ridge capping. Otherwise, if installed mid-roof, water would run down the corrugations, and when it hits the vent flashing, it would just sit and pool there.

Difficulties do arise when working with light-gauge roofing. Since you cannot climb onto the roof, you might need to choose a location that can be reached from a ladder.

Please let me know if you have any questions.

Mitchell

[Nailbag]

Hi @Ask_Itee 

I have installed a couple of these of different brands on sheds before and they only appear to come with super basic generic instructions like the one in @MitchellMc link. I guess there are lots of variables in roof construction to be more accurate/specific.

The last one I put in was on a fairly cheap lightweight shed my mate bought online to store his surfboards. I ended up taking the dome off and installed the tube through from the inside after applying a more than generous amount of roof and gutter sealant around the cut out. I then used large rivets to secure it, which I siliconed the holes then the pivots after each one was installed. I rested an old plywood panel on the roof to share the load that I could lean on as I applied another generous amount of silicone around the opening and over the riots, before refitting the dome.

Though obviously not an ideal installation method, there was no way the roof was going to support any weight and the options were this or nothing. To date it's never leaked. At least not that my mates ever complained about.

Nailbag

[Ask_Itee]

Thanks Nailbag, I'll keep your idea in mind

[Ask_Itee]

Lateral thinking at its simplest.  I did have access to the ends of the peak in shed roof, and over the weekend installed the vent.  I really did expect it to be more difficult than it was. 

A bit overkill perhaps, but mindful of me working in the area and future owners of my home doing the same, I filed off all the sharp edges of the hole where I cut with a metal cutting disc.  I'll revisit the edges of the hole and paint them with a suitable rust preventative paint after the next trip to Bunnings.

Thanks to all who contributed.

[MitchellMc]

Great stuff @Ask_Itee! 

Many thanks for the update. Glad you got it sorted.

Mitchell