So we had this happen to our slideout on our new trailer. Noticed it a few weeks back when we brought it to the house one weekend to go set up a few things inside and go over it to see if there were things we wanted our dealer to look at as we had a 60 day service appointment for the next weekend. I first noticed it after we had extended the slide and saw the bottom plastic piece that covers the joint pulled from the trim piece with the screws. I thought that it had just pulled out so I pull the trim and fit the plastic back up in there. We then ran the slideout back in and looked at it inside and saw that it pulled out again and that this end of the slideout floor was not connected the slideout wall. Son-of-a-bitch!
At this point we just took it back to the storage shed and waiting till the next weekend to take it to the dealership. Went in and spoke to our service advisor and when out and showed it to him and he said that even in new trailers, he had seen this before. We looked closely and there aren't even any screws along that joint holding the floor up into the wall. The SA said that he figured the assembler at the factory was just blasting along with an automatic screw gun and didn't even pay attention that he ran out of screws. Don't know if this is BS or not but the SA said he would get his tech to look at it on Monday and let us know how long it would take to fix along with a couple of other minor cosmetic items. Got a call Monday morning and the SA said the the tech on Saturday didn't have any parts to work on other jobs so he went again and fixed it. Drilled and shot 5 3" screws up through the floor into the wall, taped and sealed it back up.
So, I'm no so sure about the empty screw gun theory but when we picked up the trailer and ran out the slideout the first time, my wife was concerned about screws or manufacturing debris getting caught up under the slideout floor and scratching or gouging the trailer floor. I even brought a thin metal yardstick to swipe under the slideout. When I tried to use it the first time I was standing next to the end of the slide and noticed that the slide floor was sitting down on the trailer floor without any room at all. We didn't check the other end, which had about 1/2" of gap, as I was stand by the end that was broken.
Anyway, it looks like it is fixed OK, our dealer took care of us right away and we didn't have to leave the trailer there for weeks so we are mostly happy. We have at least one trip a month scheduled out through March and we have been spending a few weekends recently clearing out a space over at our family ranch to do some boondocking down by the lake. Next month or so of nice camping weather here in Tx.