Thursday, June 1, 2023


Fighting mildew wars

By Chris Dougherty
Chris Dougherty is a certified RV technician. Here is a letter he received from a reader while he was serving as’s technical editor.

Dear Chris,
mildewWe live in Florida, where high humidity is always present. We own a 25-foot Hi-Lo trailer that I try to keep lowered and covered during the winter months. We use a Damp Rid Large Room dehumidifier and run a 12 volt fan to circulate the air. Even with all this we still have musty smells when I check the condition of the Damp Rid container. I’ve had to remove the ADCO cover and raise the trailer to try and improve the inside condition. Any ideas? —George
P.S. Great site, enjoy every issue.

Dear George,
First, thank you for the compliment! We are working hard to bring everyone the best information we can!

Florida is a tough environment when it comes to humidity and mildew. Once mildew sets in it’s hard to get rid of.

Here are a few thoughts. First, I always look at soft goods like carpeting first. Any of those will hold it, as will wood products. Have you had any leaks in the unit? Concealed moisture breeds mildew, and it can grow in the wood underneath the linoleum, or in the walls or ceiling. Check the outside seals carefully, and check for any rot on interior panels and surfaces. If you can’t find any rot, I would open the unit up and remove everything (on a nice day or two of course) and spray every surface of the inside of the unit with a mildew removing solution, like a bleach and water mix in a spray bottle — just be careful about sensitive dyes and fabrics.

Lastly, keeping the unit closed up may be a contributor if the damp air is stagnant. I would consider some type of forced air ventilation that brings fresh air in and pushes old air out. I’m not certain that the chemical dehumidifier is of adequate strength to combat tropical moisture like this.

Practical Sailor did a test on a number of cleaners and mildew removers. Of the products they tested which I use every day, and did during most of my 23 years in emergency services, is Spray Nine. Home Depot and Lowe’s both sell it, and according to Practical Sailor, it is also good at removing mildew. -CD

Editor: Spray Nine products are available at Amazon.



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6 years ago

In addition to handling the moisture/mildew issue, make sure that you check your lift cables for rusting. The one by the shower is especially vulnerable. It is visible at the outer wall, by the fwd. wall of the shower.(At least on my 25′ Hi-Lo.)
The other cables are visible if you remove the ‘upholstery’ strip that covers them.
My Hi-Lo was facing a very expensive cable replacement, and that’s why I traded it in for an Airstream.

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