Water/Condensation coming in rear bunkhouse 303TG

[Heimtime21]

I have a 2013 Laredo 303TG. The rear bunkhouse has a slide out. This past weekend we experienced temps in the upper 20's a couple nights. I had water coming in the roof the first morning where the outside wall and roof meet. I assume there was water on the roof and it seeped in somehow. It rained the day before but my slides were not out. the water was all along the inside where the ceiling met the wall to the point where it dripped down the wall in some places. I looked on top of the slide and saw minimal standing water. The leak did not happen again the rest of the weekend but we did not have rain. Is there any preventative maintence I can do? I have never sealed or messed with slide out roofs.

[Jager]

Photos of area you're talking about?

[Heimtime21]

Attached are some phoos of my situation.

[JRTJH]

That looks like condensation from having too much humidity inside the RV in cold/very cool weather. In your OP, you indicated that it had rained the day before. I'd guess the outside air was already laden with moisture and inside it was even more humid. You probably had to keep wiping the walls to prevent the water from collecting. I'm sure the windows also had fog/condensation on them that you wiped off during the stay. That's a good indication that you didn't have enough ventilation and too much "moisture production"

Cooking, showering, simply breathing will add a tremendous amount of water to the air. When the walls, ceiling or windows are cooler than the air inside, that moisture tends to collect on the cooler surfaces. It is a natural process and you can't prevent it. I think the reason it occurred mainly in the slide is because the slide has less insulation in it, so the walls were somewhat cooler than the thicker, better insulated walls of the main RV body.

You can help control it by opening a window and a ceiling vent to set up an air exchange to help carry the excess moisture out of the RV. Limit the length of showers, close off the bathroom and use a power roof vent during showers. Limit boiling water or cooking without lids and use the range exhaust fan to pull moisture out of the RV (if you have an outside vent). If you don't have an outside ducted range vent, open the roof vent over the range and open windows slightly to set up some circulation to help pull the steam from cooking out of the RV. Using a dehumidifier may help, but make sure you have one that either empties in the sink or that has a large enough water storage tank to be practical. A small unit that holds 2 cups of water won't do much good when you're showering and the wife is cooking spaghetti on the stove.

In your home, you have roughly 1,500 sq ft or more to absorb the water from everyday living. Often we need to add moisture during the winter and use a "humidifier". In an RV, we have maybe 250 to 300 sq ft and the water from everyday living is a bigger problem. If you don't limit the amount of moisture released into the air and remove at least "most" of it, you'll always have condensation problems on your walls.

Another place that you may want to look for moisture is behind the cushions that lay against the walls and at the head of the bed where the mattress is against the wall. Those places typically hide condensation and can, if not managed, set up a great place to grow mold and mildew.

[Heimtime21]

Thank you very much for your reply. I did wonder the samething but was alarmed at the amount of wetness and assumed it couldn't possibly do that. The pictures didn't do it justice really. Is there any reason it did not do it on the larger slide out? Maybe more space to absorb moisture in the air? I don't remember wiping windows but to be fair the blinds were down. I found the water literally as my wife was in the shower with the bathroom door closed.

[JRTJH]

The larger slide may have more air movement or have a heat register blowing air into it which would tend to keep it dryer. Usually the ends of an RV are the most "prone" to condensation as they are most often furthest from the furnace.

When we had our truck/camper, I actually had dinette cushions freeze to the plywood "wings" which hung over the sides of the truck bed. We got up one morning to go hunting, my DW wanted to make up the dinette so the kids could eat without spilling anything and the cushions were frozen to the seats of the dinette. So, yes, you can definitely get a lot of condensation inside a small area with all the moisture we put into the air.

[therink]

This may sound counter productive however I have found that it helps to run the ac fan in fan only mode on cold nights when running the furnace. The ac fan helps to move air which helps keep the heated dryer air from furnace evenly distributed, thus minimizing condensation.
I also have a fireplace, and the ac fan also helps distribute the heat from it.
Additionally I leave the bath roof vent cracked open and run vent fan if needed.
Steve

[SAD]

I'd agree with condensation assessments. Good advice give to minimize as well.