Did I screw up my fan install?

It will be fine.

It will be fine, Some don't put butyl underneath and just cover the edges & screws with Dicor. I regularly inspect the sealant anyway. Nice thing about ceiling fans is any leaks usually become apparent before any damage is done if the manufacturer has folded over the roofing material into the well. You will usually see a drip in the inside if there is any leaking. I remove the inside shroud once a year as part of my annual inspection. Its only 4 screws.

Sorry, I'd have to disagree - anything with a flange that's secured to the trailer should have butyl tape between the flange and the surface to which it's being attached, and once that's done any potential entry point for water should be additionally sealed with lap sealant. Over time lap sealant loses it's resiliency, dries, and cracks and can't be relied upon for a waterproof seal, ergo the reason it's important to inspect and maintain on a regular basis. Under a flange how often do you think one would do that? ... NEVER being my answer, at least not until it starts leaking, which is obviously too late. Personally, I'd remove that vent and redo it properly.

SoundGuy wrote:
Sorry, I'd have to disagree - anything with a flange that's secured to the trailer should have butyl tape between the flange and the surface to which it's being attached, and once that's done any potential entry point for water should be additionally sealed with lap sealant. Over time lap sealant loses it's resiliency, dries, and cracks and can't be relied upon for a waterproof seal, ergo the reason it's important to inspect and maintain on a regular basis. Under a flange how often do you think one would do that? ... NEVER being my answer, at least not until it starts leaking, which is obviously too late. Personally, I'd remove that vent and redo it properly.

Yep.

I'd pull it up and install it correctly. It's worth the extra 30 minutes and $10 to avoid a potential leak.

It will be fine.

dan-nickie wrote:
It will be fine.

You prepared to come back in 5 yrs time and repeat this same advice for a third time after the lap sealant the OP has mistakenly used in place of butyl tape has dried out and cracked? :R

Thanks for the advise. I'll pick up some tape and some day when I'm bored and feeling energetic I'll redo it. I still have an unopened tube of Dicor.

I would leave it as is but put Eternabond over top of the sealant for an excellent belt and suspenders job.

It will be fine.