Community Forums

FrontRangeRVer · 10-21-2008, 06:29 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by wagonmaster2:
Moisture not as bad but where the bathroom wall meets the ceiling just back of the shower stall is still wet after the showers.
Wagonmaster2 </div></BLOCKQUOTE>

Condensation from the uninsulated extruded aluminum wall to roof connection....runs the full length of both sides of your motorhome.

NeilV · 10-22-2008, 01:00 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by FrontRangeRVer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by wagonmaster2:
Moisture not as bad but where the bathroom wall meets the ceiling just back of the shower stall is still wet after the showers.
Wagonmaster2 </div></BLOCKQUOTE>

Condensation from the uninsulated extruded aluminum wall to roof connection....runs the full length of both sides of your motorhome.

</div></BLOCKQUOTE>

Maybe I am more proactive about these things as I live in Florida however I do not have a condensation problem that runs the whole length of both sides of the motorhome, even when traveling in sub-freezing temperatures.

Yes if and only if I did not follow common sense about things I could manufacture a problem however the manual on my Winnebago was very explicit on the "EFFECTS OF PROLONGED OCCUPANCY" and "HUMIDITY AND CONDENSATION" spelling out what had to be done to deal with humidity and prevent a problem. If you do as the manual directs then you will not have a problem. It covers things such as ventilation, not running the hot water for long periods of time, not letting pots boil longer then needed, showering, not allowing items to hang dry in the coach and not tracking in snow on your shoes/boots. This section has been in all the motorhome manuals that I have looked at from my 95 Vectra to my current coach and the many others that I considered in-between.

These turn out to be the same guidelines I follow in my stick house so they are no big deal to me. Remember that you are generating close to the same amount of moisture that you would be when at home but instead of in a 1,200 to 2,000+ sqr ft area you have it more concentrated in only a 300+/- sqr ft space.

In a stick house many have automated vents in the bathroom and kitchen to help prevent these problems and full time ventilation of attic and basement crawl spaces so we do not have to think about them however in an RV we most times have to provide/activate these things manually.

You also have no overlap between sidewall and roof insualtion in most stick houses with the roof insulation ending at the wall plate and not extending over it so most stick homes and Winnebagos are the same as far as the extent of the insulation goes, there is no difference.

Bottom line is that we all need to be more proactive about reading and following the instructions in our owners/operators manuals to prevent/deal with these things and keep the warranty in force.

PeteB · 10-22-2008, 02:16 AM

I agree with Neil as I have been in Motorhomes manufactured by various Companies and they all have the same problem. Where the roof and walls connect is a structural member that cannot be effecively insulated as it is usually metal and the cold is conducted around any insulation installed. Proper ventilation and consideration of the small volume of air in a Motorhome will usually allow us to minimize the problem.
Be proactive and remember that just opening a vent will not be enough as you need an additional opening to allow the air to be exhausted. Air will not flow out unless it is replaced as nature doesn't like a vacuum.

Pete

TXiceman · 10-22-2008, 03:05 AM

The amount of moisture the average person expells to an area through the skin and breathing will range from about 0.13 (not active) to 0.195 (active) Liters/hour. So over a period of a few hours and two people plus any pets, they can put a fair amount of water vapor into a confined space. When the amount of moisture in the area is too great, it will easily condense out on any surface colder than the dew point of the moist air.

With the normal amount of moisture added just due to your occupancy, you add water with cooking and bath activities. Since the volume of an RV is so small, the moisture will quickly build up to the point that it will condense on the colder surfaces.

The need to vent on a part-time to nearly continious basis is dependent on the size of the RV and the number of occupants.

Part of the problem is that not all of the moisure will condense on the surface of the walls. If the wall does not provide a godd moisture barrier, some of the moisture will move into the wall and now condense inside the wall at times. This leads to internal corrosion and rot problems.

Moisture will always drive from the more moist and warmer area to the less moist and colder area.

The areas where walls and roofs meet have very little insulation due to the construction methods, so these joints will be colder and draw more moisture.

In short, you need to keep a high vent open a small amount, vent when cooking and showering and do wipe down the shower walls with a squeege.

Ken

Wayne M · 10-22-2008, 05:08 AM

Ken hit on something that I did not realize until visiting my brother's stick house this past summer. He is up in New England and has a Bath downstairs in the 'cellar' that the men use. It has a full shower. He had a very nice 8 inch squeegee hanging on a hook in the shower that we could use to squeegee the walls when we were finished showering. It really helped with not only the dampness, but the spots left by water.

I'm buying one for the MH, and soon.

Following the advise of others about venting will help with the other areas, besides the shower.

Steve Rankin · 10-30-2008, 02:31 PM

We always have at least 2 vents open in our boats and in our RVs. We also squeegee and wipe down the shower after our showers. It also helped that the shower dome in the Beaver was a double dome which improved its insulation. As a result, the only place we ever get condensation is the windshield of the DP on cold nights after the privacy curtain is closed because the air flow is cut off. So, we lay towels at the base of the windshield to absorb any water that drips down the inside of the windshield.