Keystones says a drop of 1 1/2" is normal in ceiling.

RV manufactures have to claim structural defects/problems are normal, that saves them lots of time and money in warranty claims.

I know this NOT a building, but, from a structural engineering perspective, the UBC (Uniform Building Code) limits deflection in a beam/roof/floor to L/240.

L = span in inches

So if your RV roof spans 8 feet, (side to side) L = 8 x 12 = 96 inches

96/240 = .4 inches or about a half inch, which, FEELS about right.
1 1/2" seems a little high.

Industry standards ahhhhh hell, who needs 'em?

Second thought: If you could get the floor directly below to deflect the same amount, . . . . . problem solved! No deflection, that's called camber. Then drill 1" holes in the roof and your drainage problem is solved too! And you get a free rainwater catch system.

Chum lee

rjsurfer wrote:
.....Keystone states that a 1 1/2" drop or dip in an RV roof the first year is within normal specs........

That's true if you store your golf cart on the roof.

In my opinion the customer is the best sales person and the sales person is a form secretary. I would not expect or accept any change in the ceiling/roof. Sounds like an issue!

Sounds like the Dealer who said the ladder to the roof was not actually intended to be used, after they backed our Fifth Wheel into a building bent it and tor e up a section of roof, and said I did it by climbing on it.

myredracer wrote:

riven1950 wrote:
your title says ceiling. your post says roof.

Which is it? Not that either one would be good but might make for different responses.

That makes more sense and is probably what's wrong. Easily fixable compared to a roof issue. Hopefully OP will come back and clarify.

The article states "roof", their exact words... "When they checked,they found a 1 1/2" sag in the roof surrounding the air conditioner".

To find a sag in the roof or ceiling is unacceptable either case.

Ron W.

HHMMMMMM --- Sounds like my Keystone roofing system.
Our 2016 Cougar fifth wheel roof started just coming apart a few weeks ago. The plywood was actually loose from the front cap half way back the length of the trailer. The rubber membrane was billowing as we drove down the road.
We had trouble with this unit from the first day out. Keystone will not stand behind anything they build.
Wisely, the moderators here will not allow me to fully express myself about Keystone products. Suffice to say I do not own a Keystone any longer and will never say anything in support of their products.
See ya out there -----------

riven1950 wrote:
your title says ceiling. your post says roof.

Which is it? Not that either one would be good but might make for different responses.

That makes more sense and is probably what's wrong. Easily fixable compared to a roof issue. Hopefully OP will come back and clarify.

your title says ceiling. your post says roof.

Which is it? Not that either one would be good but might make for different responses.

Should look something like this.....and ideally the entire roof is crowned.