2017 3791RD Rear A/C condensate collecting on roof

[JamesDean334]

I was on the roof of our unit sweeping off slides before bringing them in and I noticed water (A/C condensation) standing around the perimeter of the rear A/C. There's a "valley", for lack of a better term, that's about 1/4~3/8" around the whole unit. Is this normal? This was the first time I'd gotten on the roof after the A/Cs had been on for an extended period. I'd never noticed this valley before and wouldn't have noticed it this time had it not had standing water in it. There is no leak inside the camper in this or any other area. My plan is, now that it's back in the barn, to get back up there and check for any obvious reason for the valley. If nothing seems to be wrong, should I fill the valley with Dicor, apply Eternabond tape to the perimeter to give cover the valley and create a slope for runoff, or leave well enough alone??

[Pull Toy]

The old adage “ If it ain’t broke, don’t fix it! “ is my first thought. The roof hasn’t leaked in 7 years, so it probably won’t leak now. If you park slightly off level, it will drain by itself. When you think about it, it’s been wet up there every time it rains too.

The “puddle” may actually help a little in your cooling. Evaporation has a slight cooling effect.

Good luck,

[jxnbbl]

I just installed an AC for the first time. Structurally the AC sits on the roof, the inside bracket is bolted to it and 4 long screws "sandwich" the roof structure between the AC unit and the bracket on the 4 corners. I can imagine that *if* the structure between the ceiling and the roof was not solid or there was a slightest gap either the roof or the ceiling would "indent" to close that gap.

[JamesDean334]

When I have time to get back up there this weekend, I'm going to check the structural soundness of the unit and its attachment. If everything is secure and no indications of anything undesirable, I'm going to make sure the seal is good and let'er wobble like it is. Like I said, no leaks.

[chuckster57]

FWIW, if it’s a Dometic AC, the torque spec for the4 mounting bolts is 40 inch pounds.

[JRTJH]

Originally Posted by chuckster57

FWIW, if it’s a Dometic AC, the torque spec for the4 mounting bolts is 40 inch pounds.

I was thinking the same thing: If someone really "cranked down the screws" they may have crushed (or compressed) the roof structure and made an indented space from the forward and aft roof rafters and squeezed those directly under the A/C unit, making the roof "cave in" at the 14x14 opening.....

I know lots of people who really "squeeze the gasket/seal" in hopes that the air conditioner unit won't "bounce off the roof if we hit a bump".....

Maybe/maybe not, but worth a look to see.....