Two Fantastic fans in on RB van?

[ANZAC]

Originally Posted by LenS

Our two fans were on the vans original metal roof. There has been several posts in several threads that SMB is against cutting holes in the penthouse roof.

Yes if you have a penthouse roof you don't want a fantastic fan in it, trust me. Cracks, leaks... I had to replace my PH roof because the PO but one in.

[Viva]

I wouldn't say that across the board. Certainly a poor or even "medium good" installation could cause problems, mostly likely with leaks compromising the wooden reinforcement/core material. This happens often in boats with cored decks where sub-standard installs are done. And I don't mean that SMB doesn't do them because they are not capable - I'm sure they would be - but perhaps they just choose not to go there. Fair enough as it is somewhat "fussy" labor to do a good job, and maybe they feel it wouldn't be cost effective.

However if a person wants a vent and is willing to do the work themselves, I think it could be accomplished with no "danger" to the top (in fact you could likely improve a few things "while you were in there"). The basic idea is to close out the core (which was inside "ribs" on my top), and to mold in a flat surface on the roof for the vent to land on (using thickened epoxy/fiberglass reinforcement cloth/paint-or-gelcoat). I would say it's a job just about anyone could do if they were willing to spend some money for good materials, and do a semi-painstaking job with proper prep, fairing, etc. It would be costly to have it done because it's a bit time consuming, and also is the kind of job that requires an hour at a time spread out over many times - which is inefficient for paid labor.

Whether or not that is "worth it" to anyone just depends; but I don't see anything that would make it specifically inadvisable if done correctly.

[ANZAC]

Originally Posted by Viva

I wouldn't say that across the board. Certainly a poor or even "medium good" installation could cause problems, mostly likely with leaks compromising the wooden reinforcement/core material.

If I recall SMB's opinion was that no matter how you did it, they would always be leak prone because of the forces/flexing that occurs. So I would say, point us to a good, non-leaking, PH fan installation and we might believe it.

Personally, I am super happy the fan is gone from my PH.

[LenS]

Originally Posted by ANZAC

If I recall SMB's opinion was that no matter how you did it, they would always be leak prone because of the forces/flexing that occurs. So I would say, point us to a good, non-leaking, PH fan installation and we might believe it.

Personally, I am super happy the fan is gone from my PH.

Installed my penthouse vent 5 years 11 months ago.

There are several penthouse roof configurations out there and so I can only refer to the design that came with my specific penthouse. I didn't at the time see it as a big deal and still don't. One should know what one is doing though, have confidence in what you are doing and make sure to maintain the roof integrity.

As installed in June 2009


As of two weeks ago....May 2015


Ye "old" Westphalia. Nothing sacred or magic. But you must have a desire for one.

[Viva]

Well, included in my idea of a "proper" job is taking care of any flex, because I agree, flex would not be good. This is not an uncommon thing to do on boats (add a hatch), and there is often some work to be done to make the surface flat (decks curve), reinforce it, or etc. Just part of the deal.

I can see where just a "pop it in" job could cause more problems than benefits. I would want to be rid of that type too.

LenS: Yours looks like a great job (not that I'm surprised).

[ANZAC]

I have a theory that if the fan wasn't on the centerline (i.e. was closer to the sides), it might pick up less flex.