Aluminum vs Wood Studs in Walls re Condensation

[rickd]

I'm actively looking for a 5th Wheel right now and am a bit overwhelmed by the variety of manufacturers and models.? However, I am making some progress in narrowing down the field a bit and determining what I want in in 5er.? One 'big' question I have is about the impact of aluminum wall studs vs kiln-dried wood studs.? I'm not so much concerned about the relative cost or strength of the products, although that is important, I am more concerned about the aluminum 'sweating in cold weather', causing condensation which results in delamination of the 5er's inside walls.?

I live near Victoria, B.C. on Vancouver Island.? Our winter here is very mild - hardly ever see snow at all, maybe one or two days a year.? Rarely goes below freezing either if that makes any difference.? Also, I doubt very much we will be heading anyplace that is colder than here - the opposite would be true especially in the winter - Arizona and California sound nice!

I read somewhere, I can't remember where right now, that aluminum studs could cause condensation problems when compared to wood.? If that's true, is it significant?? Does it always happen?? If so, why do manufacturers use aluminum and why do people buy them?

This will make a big difference to my final decison on what 5er manufacturer I eventually choose.? If aluminum is a potential problem then I can scratch a whole lot of 5er's off my list right now.

I would appreciate any information anyone has to offer on this topic.? Thanks.

 

[Gary RV_Wizard]

Our motorhome has steel structure and I've never noticed any significant condensation, nor have I heard of any complaints about it in my many years on this and other forums.  I suspect the article you read was speculative rather than an informed report.

Some times on a cool damp morning, you may see the tracings of a frame member under the skin, becasue the metal is indeed a better conductor than the filon skin. That may lead to conjecture about internal condensation, but I doubt if it is significant or even a noticeable factor.  Delamination is not a significant problem in newer RVs. When it does occur, it is usually traceable to outright water leaks (roof seams or windows) or factory fabrication defects.

Just my opinion... others may have a different perspective.

 

[hankpac]

Our Avion is an '83. Total Aircraft type ribbing alum skin with spray on foam insulation.. the paper, wood, and other wall linings are pristine. It spent most of it's life in wet Texas, hot dry summers and cold winters, and now is in Eastern Oregon, freezing winters, hot dry summers, lots of moisture, etc. No problems from moisture. that addresses your original question I believe. No damage from any moisture.
Condensation will ALWAYs occur in a closed environment. even if you are not cooking, just normal body moisture and breathing releases a significant mount of water into the air (one quart per day just for sweat, and one to two per day from the lungs per person).
That's why your windows sweat when it is cold out there. That's why many manufacturers put weep outlets in the windows.
You can mitigate the problems by NOT keeping things tightly sealed. Open the roof vents a crack, and a window a crack. That lets the moisture out. Yeah, I know someone is going to whine about the draft, but you can work with that by being a little creative about which ones you open. Use the vent fan when cooking, especially when cooking bacon or other product that smells strongly, or vaporizes.

In our park model on the gulf coast of Texas (where it is absolutely downright damp!) we kept coffee cans full of baking soda in each room during our absence. It helped. since we where hooked up, to shore power, we ran the A/C as soon as we opened up, to dehumidify the air and carpets/wood/mattresses.
Look over the rig closely, check the wall paper at is lowest point. If you smoke, get someone who doesn't to go into the rig and sniff around for the odor of mildew. Look for staining around the base of closets, under the bathroom cabinets, and stains on the rugs. if the paper is lifting, either pass or consider negotiating a lowering of asking price based on repairing the product. Look at the wood at the bottom of all walls, for rot.