Vent fan cover replacement - why can't I do this??

[TundraTower]

We have a 2014 TT that came with a Fantastic Vent fan in the bathroom. After a few months ownership I had the dealer install a regular Maxair vent cover.

Recently got caught in hot camping weather and realized how little air our vent fan was moving. After a bit of research and finding that I could not get a bigger fan & motor (more power!), I decided I needed to replace the Maxair cover with the Fantastic vent cover made for this fan. Their video on u-tube is quite convincing.

Anyway, I was reluctant to buy the Fantastic vent cover because it requires that you dig out the caulk and remove the fan mounting screws to mount the vent. I ordered it anyway and went up on the roof today to swap them out.

What I found was the brackets for the Maxair are located such that those bolts will match the holes in the Fantastic vent cover. The difference is the Maxair brackets are bolted into the side of the plastic fan housing with a sheetmetal screw, whereas the proper mounting for the Fantastic Vent is to use 4 of the existing screws that hold the fan to the horizontal surface of the roof.

I went ahead and used the existing Maxair brackets and it went on just fine.

Has anyone else run into this, and/or know of a reason why I should not leave it this way way???

[TundraTower]

Just to close the loop:

Weather here finally dropped below 100F for a few days so we took a short camping trip with the new vent cover with modified installation as described above. This was about 80 miles down the interstate and the cover stayed put.

As someone said above: "If it doesn't blow off next time you drive it. leave it like it is! ".

Sounds like a plan.

[j-d]

Sorry about the Link. I think it's fixed. What you've done should be fine. Each installation seems to be a little different on these things. Ours don't sit super close to the roof skin either. They'll keep most rain from splashing in, and will let you drive with the vent lids open. It's all good.

[TundraTower]

I get an error message from your link J-D, but phone lines have been screwed up in my area all day. Somewhere there is a backhoe operator that has had a very long and unpleasant day today.

Anyway, I did take note of the height difference. As best I could evaluate, my short-cut mounting on the existing L brackets resulted in a hood that is about 1/4" higher than the brackets that came with it.

HOWEVER, I also noted that the new brackets have a slight L-bend DOWNWARD, and it looked to me that this would put the head of the mounting bolts right against the rubber roof liner under said bracket. This was another piece of info that led me to use the existing L brackets.

[j-d]

This is the Thread where this issue came up recently. Don't know why I couldn't search it up in RV.net. Used gOOgle and here it is. She did what I remember, dug the sealant away from the screws, installed the brackets, then applied new sealant.

I agree this mounting approach is disappointing. Disturbing a sealed roof is worrisome. I can picture, though, were starting out with the mounting right flat with the flange could result in the cover being closer to the roof surface. Was just up there today, and brackets mounted over sealant look pretty cockeyed.

[time2roll]

Well there is some truth in that.

Does have a rain sensor and in the rare case that it does rain I tend to leave it closed.

[j-d]

smkettner wrote:
When I installed my Fantastic Vent I skipped the extra vent cover completely.
Have not missed it yet.

That's because "It Never Rains in California!"

I'm starting to remember another vent project. OP was questioning digging through the sealant. Finally did, and the project then went according to instructions. Applied sealant once the brackets and cover were installed.

[time2roll]

When I installed my Fantastic Vent I skipped the extra vent cover completely.
Have not missed it yet.

[IAMICHABOD]

That is the Main reason that I went with the Maxx Air Fanmate It attaches to the side of the vent like all the other Maxx Air vents. It also has clips the allow you to quickly open the cover and clean the vent and vent cover.

Unlike the Fantastic Cover that you have to open up the caulk and attach the mounting brackets to the roof,then reseal,I really do not like to disturb that seal.

[TundraTower]

j-d:
Sorry I did not think to take pictures.

The existing Maxxair brackets that I re-used are exactly what you describe. It is an L bracket, with the vertical side mounted to the side of the "throat" of the fan, and then the Maxxair cover was bolted to the horizontal legs.

The Fantastic vent came with flat brackets. You are supposed to remove 4 of the existing vertical screws that hold the bottom plastic flange of the fan housing onto the roof and use new screws in the same holes to fasten this flat bracket horizontally. Then the cover mounts to the flat bracket similar to the horizontal leg of the L bracket.

The downside is that all of this is covered in a 1" wide layer of caulk, which I and others are reluctant to disturb.

[j-d]

FanTastic uses good materials. Even the covers, lids, whatever you call them, rarely crack but you get a free replacement if one does. That flange will probably outlast everything around it.

Maybe I'm confused. The brackets I've seen for vent covers have a 90* angle. A short leg mounts to the vertical part of the fan/vent flange. Then the long leg mounts to the cover. Mounting surface of cover is parallel to roof surface. Nothing goes down into the roof structure, through the covering, or through the vent/fan flange. No chance to leak.

[TundraTower]

Thanks for your input so far.

I removed one of the "sheetmetal" screws during installation yesterday to locate the roof screw I was supposed to use in order to dial in the exact hood location I needed to match. The sheetmetal screw still had caulk in the threads so assuming all of them were caulked I'm not really concerned about them backing out. And, they have held the Maxxair hood on there for almost 3 years.

My bigger concern was the hood being connected to the square plastic flange of the fan instead of screwed into the wood (I assume) under the rubber roof liner where the fan itself is mounted.

The point about plastic becoming brittle after a few years is something to think about.

[DutchmenSport]

I have 3 knock-off vent covers that are plastic and simple screws through the plastic into the metal brackets set up (no nuts). Had them installed when we took delivery of the camper. Been up 3 years now and we've traveled quite a few thousand miles since ... quite a few thousand! All 3 are still up there, no problems at all. I think you are fine. Try it a while and see what happens.

I'm expecting after 5 years for the plastic to start getting brittle. This happened to our previous camper. We did not have covers, just the factory crank vent covers. About the 5th year of ownership the camper got hit by hail which busted out all 3 vents (plastic lids). We had them replaced no problem, but the plastic was extremely brittle and had no "give" any more. That's probably why the hail hitting them finally broke them out.

So, I'm expecting about the 5th to 6th year of ownership for these cheap-o-knock off brad vent covers to go brittle too. But if hail destroys these, I'm not out much. Simple to replace with just screws.

[j-d]

If I'm following this, the question is whether to mount the cover brackets to the plastic FF frame with "sheet metal" or "machine screws" with nuts.

I added MaxxAir-II covers to our FF's and doggedly took the FF's far enough apart to use the machine screws, nuts, and washers they provided in the hardware kit. Nuts worked loose. I spoke with a tech who said he just uses sheet metal screws and has not had problems.

Unfortunately, some "techs" aren't very careful and strip things out using power tools. Sometimes they grab screws that are too big, too small, too long, too short. I'd like to hire more work out. Then I see the results and wand to do more work myself.

[Joe417]

The brackets should work fine fastened to the side of the Fantastic fan, but I've never seen them installed with sheet metal screws. The housing is plastic. I'm not sure a sheet metal screw will stay tight in the plastic.

They come with machine screw, washers, and nuts. They are suppose to drill a hole and use a nut and washer. That requires 10 extra minutes and possibly a second person to hold the hardware from below while the person on the roof tightens it. I think your dealer saved a few cents in labor by not using machine screws.

I think I would replace those sheet metal screws with stainless machine screws.