Hole position for bedroom fan

[gerryg]

Morning all. I'm replacing the ventilation fan above my fixed rear bed. A PO has done similar but offset the fan 14" to one side.

Should I fill that hole and install the fan on the centreline? Or leave it where it is? Note that because the offset is 14" a hole on the centreline will share a side with the existing hole. Does this complicate things?

As an aside, note how my Transmode has almost no spray foam...

 

[kidjedi]

Unless having it off center bugs you (visually), I'd leave it. Airflow difference should be negligible, and the fewer times you mess with the roof, the better.

 

[gerryg]

Thanks! I really don’t want to move it. I guess we could choose which way we sleep depending on whether we want the breeze on our faces or feet.

 

[dsmithy]

If you need a dissenting view, I have one. I hate to see that missing rib and how the roof is weaker there. I realize that filling the hole and sistering something to the rib would be more work and a pain. But if it were my coach, I'd feel better about the roof structure. It's easier if it is away from the ladder, but I walk around up there to access my roof pod. If you have no roof pod, I suppose it doesn't matter as much. JWIT

 

[gerryg]

Thanks dsmithy. I was hoping everyone would tell me not to worry and leave it where it is.

I don’t have a roof pod or even a ladder at this point. If I don’t move the hole to centre I will certainly add another rib parallel with the one that has been cut, just inboard of the hole.

 

[kidjedi]

If you need a dissenting view, I have one. I hate to see that missing rib and how the roof is weaker there. I realize that filling the hole and sistering something to the rib would be more work and a pain. But if it were my coach, I'd feel better about the roof structure. It's easier if it is away from the ladder, but I walk around up there to access my roof pod. If you have no roof pod, I suppose it doesn't matter as much. JWIT

I *think* he will be ok. No one will step where the fan is (hopefully!), so the fact that there are cross braces (side to side) on either side of that area with struts in between the cross braces, should make things ok. It is unfortunate that the PO removed a structural strut, but unless you are stepping *right* next to the fan (inside where the other struts exist), it shouldn't be much of an issue.

It looks like the PO put the piece of wood in there to address this issue. If it were my rig, I would put an aluminum strut with a similar profile on the center side of the current hole. The appropriate way to do that would be to cut the strut to size (in between the two cross braces), then use Sikaflex or butyl tape between the exterior skin and strut and rivet from the top through the strut.