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7 Tips to Reduce Moisture Problems in Manufactured Homes

Water is one of the most damaging forces on earth and can destroy a home quickly or slowly. Repairing water damage in homes is a multimillion dollar industry in the US. Instead of having to repair water damage after it occurs, this article will help you understand moisture problems in manufactured homes. 

HUD produces some extremely in-depth resources via PDF, bound book, pamphlets, and ebooks on a variety of housing and community topics. There are only a handful of resources for manufactured housing but what they have produced is very informative. One of their resources is a PDF called MOISTURE PROBLEMS IN MANUFACTURED HOMES: UNDERSTANDING THEIR CAUSES AND FINDING SOLUTIONS. We’re going to pull the most valuable information from it and try to make it easy to digest. Ready?


Tips to Minimize Moisture Problems in Manufactured Homes

moisture problems in manufactured homes - moisture production from everyday activitiesEveryday Activities Creates Moisture that Can Damage your Home 

Moisture problems in manufactured homes can begin when excess amounts of water are dumped into the air by common household activities like cooking, bathing, heating, and even mopping. So everything we do damages our homes. Nice.

Luckily, using ventilation fans during these fun daily activities will help a ton but be sure you keep them on for a bit after you are finished with your activity so the fan can pull as much moisture from the air as possible.


Bigger is Not Always Better (when choosing the right air conditioner or furnace for your home)

I owe my algebra teacher in 9th grade an apology because I have had to use her fancy formulas in real life and way more than once. There is a LOT of math used in construction and blogging. Who knew?

I don’t quite understand it all but a central air unit that is too large for your home can actually cost a ton more to cool it, and it can create a lot of moisture in the air that can damage your lovely home.

HUD states that “Equipment that is too large will turn on and off frequently, allowing humidity to build up indoors” and they seem to know what they’re talking about most of the time so we’ll leave it at that.


Always Vent Your Propane and Kerosene Heaters (and not just because it can kill you)

Carbon monoxide will kill you so you really should reduce every chance it has to get to you. There’s another reason you need to vent your fossil fuel heaters: they can produce a lot of moisture into the air.

HUD writes that “about a gallon of water vapor is released into the air for every gallon of fuel consumed. This is a significant source of water vapor that can quickly cause damage.”


moisture problems in manufactured homes - closed off rooms and closetDo Not Cover your Floor Registers or Neglect your Unused Rooms and Closets (they miss you)

In manufactured homes, your heating and cooling are distributed through ducts in the floor or ceiling. Covering or closing these registers can create an imbalance in the system which, in turn, creates cold spots which increase the potential for moisture condensation.

In (some of) HUD’s words:  if warm air cannot enter a space (whether it be a room or closet) the air will get “cold enough to significantly raise the relative humidity level in the room, supporting mold growth.”


Your Filters Need More Love

Apparently, your heating and cooling filters do more than keep cat hair down? HUD says they can “interfere with an air conditioner’s ability to remove moisture from the air, and in some cases interfere with condensate drainage.”

Filters should be cleaned or replaced a bit more often than most of us realize. HUD recommends that we consider using pleated filters for better dust control and better dehumidification.


More Sources of Moisture Problems in Manufactured Homes

The list above is just a start. Unfortunately, there are many more sources of moisture that can damage your home:

Poor Site Drainage

Site prep and grading is so very important when it comes to a healthy and longlasting manufactured home. It doesn’t just stop at installation, as an owner you need to be on the lookout for puddles, leaks, and other issues that can damage your home.

To put it simply, there should be no standing water under or around your home.  Sometimes, that means you need to install complex drain lines installed by professionals and sometimes that just means you need to dig a little ditch. Let’s always hope for the latter.


Crawlspaces and Skirting

Under that gorgeous manufactured home of yours, there should be a cement slab, gravel, or polyethylene sheeting that completely covers the ground so that moisture from the ground can’t become condensation that reaches your home.

moisture problems in manufactured homes - Crawlspace moisture

Your manufactured home’s skirting can also be the source of moisture issues in your home. Warning: more math stuff. Did you know that there are formulas that should be used when designing and installing skirting on your home? You need 1 square foot of ventilation for every 150 square feet of skirting. You also need to have vents within 3′ of every corner, so you don’t get dead air pockets.

Your dryer vent can cause moisture and fire. Without proper maintenance it could 1. catch fire, or 2. cause condensation. Crazy, huh? You want to make sure it is properly vented outside of the crawlspace.

Related: Dryer Safety 101 – Cleaning And Maintaining Your Dryer

Of course, you want to make sure your plumbing pipes aren’t leaking. Even a small leak can create a HUGE problem over time.

Keep the Thermostat Set Above 75°F in Hot, Humid Climates

Apparently, the writers of this HUD PDF has never been to Florida in August. Setting the air conditioner below 75 just doesn’t cut it sometimes.

Keep the thermostat set at or above 75°F in the summer. In high humidity climates, a lower setting could cause water to condense inside wall cavities.” Umm, OK, HUD, whatever you say…….

If you are like me and don’t see yourself keeping a thermostat above 75 during August in the South, it’s probably a good thing to learn how to recognize moisture problems in your manufactured homes.



moisture problems in manufactured homes - sources of moisture


How to Recognize Signs of Moisture Problems in your Manufactured Home

Big moisture problems start as small ones, and any moisture problem is more easily cured if discovered early on.

The following are warning signs of possible moisture problems:

  • persistent musty smells
  • discoloration on walls or ceilings
  • swelling of the floor, wall, or ceiling
  • condensation on window glass
  • standing water under your home



These tips are really just the tip of the iceberg when it comes to moisture problems in manufactured homes. If you are seeing drops of water dripping from your ceiling or running down your walls or windows, you want to start the hunt to see what is causing it and how it can be corrected. Hopefully, it isn’t too serious.

Thanks for reading Mobile Home Living! We appreciate you so very much!

Crystal Adkins

Crystal Adkins

Crystal Adkins created Mobile Home Living in 2011 after buying a 1978 single wide and searching online for mobile home remodeling ideas but finding very little. Today, it's the most popular resource in America for mobile home information and inspiration and has been visited over 40 million times.View Author posts

Join the conversation!

  1. I have learned my furnace/ac system is too large for my 14×80 mobile home. I never had any problems until new underpinning With 2 1/2” insulation was installed a couple years ago. Moisture is now tearing up my floors. 2 bathroom floors have been replaced. It only happens when a/c is ran and the buckling starts around the vents. I had vents installed on each corner is this enough? My son wants me to apply a construction ground cover. I question dehumidifier. Desperate for answers! Would appreciate your input.

  2. Candice L Gateley

    My floors are swelling just around the air vents in the floor. I’ve had multi people out here who gave different opinions. I don’t know what to do at this point. Sure need help..

  3. We have major issues with moisture between our plywood subfloor and flooring which is vinyl planks, We do not have a vapor barrier underneath. Could this be causing the problem?

  4. the article says to keep the temperatuer at 75′ to avoid moisture from forming. I usually keep mine at 72 in a traditional house but that is to keep the humidity at bay. I will have to change my ways.

  5. Ty for this page. It is hard to find good info on Mobile homes. They have such a taboo around them.

    I dont like air on when it is about 78 or 80 do I need to turn it on or is it.ok to not use it

  7. Doors and windows are typical sources of leaks in all homes. If I had to guess the wood and caulk/sealant used has dried out over the years and is allowing water to get through. It’s likely been doing this for a while.

    Luckily, it isn’t a terrible chore to replace sub-flooring in a mobile home.. When you do it I’d use plywood or OSB over MDF/particleboard.

    Best of luck!

  8. Mobile has a patio door entry with porch a/b section no cover on porch, floor need replacement in kitchen area where entry door plus soft spot around dining area also. Is this water leaking coming from section from the patio door entry. Need to replace floor been in trailer 2 yrs and notice getting worse.. 2014 trailer notice not 3/4 plywood looks like particles boarded.

  9. Hi James,

    I’m not an installation or land prep professional but from what I’ve read I would spend money and focus on getting your land tested and graded before worrying about the type of slab. Give that moisture a place to go first. From there you can do runners, pads, or slab (depending on your land and frost line). Keep in mind, tie-downs are just as if not more important than the foundation. Make sure the tie-downs are installed correctly regardless of what foundation type. That way, you can get the home de-titled and classified as real property (depending on the state, of course).

    Best of luck!

  10. Hey! I think I know what you are talking about. You can buy new flashing in several thicknesses, colors, etc that would be a unique addition to your entryway while also protecting the home. I bet a nice copper would look great and the patina would be cool after a couple of years.

  11. Hi Michael,

    You’ll definitely need to get the insulation replaced. I would contact an insulation company and check to see what they charge for the different types of insulation (rolls, spray, etc.). You will have to go up under the home to replace so this will be a labor-intensive job – if you can find family and friends to help that will save you a lot of money.

  12. Our manufactured home was flooded. The insulation underneath is wet from the flood. How can we get this taken care of and how can we find someone to do the work. Any information is appreciated.

  13. Hi Crystal, Another thing too, is to update seals around your windows and doors as soon as you can. I am in the process of doing all mine, and I can tell a difference….not only in keeping the heat/cool inside, but the draftiness too. Its very humid in NC (just above the Low Country State Line).

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