RV Repair Manual
for the RV Do-It-Yourselfer
The air in a closed up RV will contain varying amounts of moisture, depending upon the local climate and the storage methods utilized. If you are able to connect to shore power, during the storage period, an electric dehumidifier is a very good safeguard against a high humidity condition. Otherwise, one or better yet, two, DriziAire dehumidifiers is advised. Open a roof vent or two, if you can, to allow moist air to escape.
As a concerned RV Technician, I am totally against the tarping of an RV. If your roof is maintained and in good condition, it will withstand the forces of Mother Nature. If you simply must "tarp" your unit, build an "A" frame type of structure to repel rain or snow while allowing air to circulate beneath the tarp and above the roof of the RV. A tarp laid on the roof and draped down the walls, is an invitation to dry rot - you want the moisture to escape - not to be held in, as a tarp will do. Also, a tarp will move with the wind, regardless of how well it is secured. This results in chaffing of the sidewall paint, and we don't want to discuss that in this article!
Clean and remove your battery(s) and store in a cool place. Top up the water level and check/recharge them monthly. Deep cycle batteries will self-discharge in a month and a discharged battery is not a happy battery. Use only distilled water to top off the water level in the cells. An uncharged battery will freeze in sub-zero weather if left outdoors.
If you store your RV for any length of time, it is best to provide a
RV's are not constructed to be houses ... they are made to be vacation homes.
Normal house construction includes a vapor barrier between the insulation and the outside environment.
This prevents moisture build up in the walls.
RV's do not have a vapor barrier.
Houses are designed to maintain an even temperature and a more or less even humidity level ...
therefor a vapor barrier works to keep that level constant.
RV's are used for a period of time, and then stored.
The temperature and humidity level in an RV will vary greatly from periods of activity to periods of storage.
Even during storage periods the temperature and humidity levels will vary greatly according to the prevailing outside conditions.
A vapor barrier would trap moisture inside the RV ... not a good idea!
What does this mean?
Is this bad?
Yes! Moisture breaks down the bond in laminated walls and leads to dry rot in stick and glue RV framing. Moisture promotes mold growth and other nasty things.
If your RV is near an electrical source, a powered dehumidifier is a good idea. If no power is available there is a product called Dri-Z-Air that uses crystals to absorb moisture from the air.