Home Improvement Expert Danny Lipford

How to Prevent and Remove Mold in Your Home

By:

Danny Lipford in moldy room

Mold is all around us and in every breath we take. It plays an important role in the natural process of decay and is used to make everything from cheese to penicillin. If allowed to grow unchecked inside your home, however, mold can result in damage to both the structure and your health.

Health Effects

Exposure to most mold usually only causes minor allergic reactions—such as sniffling, watery eyes, and sneezing—that subside a few hours after leaving the infected area. Some people are more sensitive than others and may experience a stronger reaction that can include difficulty breathing and asthma attacks.

Several types of mold release toxic substances called mycotoxins. Exposure to high concentrations of mycotoxins from Stachybotrys (a greenish-black green mold that grows on cellulose material such as wallpaper, cardboard, and wallboard) or Chaetomium (a white to gray colored mold found on decaying wood and water damaged drywall) may lead to more severe health issues including chronic bronchitis, heart problems, and bleeding lungs.

There is still an ongoing debate in the scientific and medical community about the health effects of this so called “toxic” mold.

Mold on wall framing

Mold growing on wall framing after flooding.

Where to Find Mold

Mold feeds off organic matter and requires a moist environment to grow. Typical areas where mold can accumulate in the home include:

  • Bathrooms, kitchens, and laundry rooms.
  • Basements and crawl spaces under house.
  • Heating and air conditioning systems.
  • Pipes and ductwork.
  • Around windows.
  • In attics due to leaking roofs.

Cleaning Up Mold

If the mold is limited to an area of less than 10 square feet, then you might be able to clean it up yourself. Areas larger than that should be handled by a professional.

If you decide to enlist a professional, make sure they are trained and experienced in mold cleanup. It is also a good idea to request and check references from past jobs to determine the quality of their work.

Removing mold yourself:

  • Wear rubber gloves that go mid-way up your forearm. Household rubber gloves are fine for detergent use while neoprene rubber gloves are best for stronger cleaners.
  • Use an N-95 respirator, which is available at most hardware stores.
  • Equipment for cleaning mold

    Equipment for cleaning mold.

  • Wear eye protection, preferably goggles without ventilation holes.
  • For mild cases, scrub with warm water and detergent.
  • For more severe problems, use a solution of one cup bleach to a gallon of water. Never mix bleach with cleaning products containing ammonia as it can cause the release of toxic gas.
  • Dry the area thoroughly. Remember, moisture is mold’s best friend.
  • When done scrubbing the area, there should be no visible mold or moldy smell.
  • Make sure the area is completely clean and dry before painting or caulking.

If you suspect mold in porous surfaces or carpets, it is best to throw them out. It is virtually impossible to get mold out of these materials.

Mold Prevention

Since mold loves moisture, it’s important to remove the source of water to prevent it from returning.

Potential problem areas to address to keep mold at bay include:

  • Roof Leaks: Check attic for roof leaks, and repair any that are found.
  • Wall Leaks: Weather strip and caulk leaky windows.
  • Window Condensation: Install insulated glass or storm windows to prevent condensation problems.
  • Cleaning mold with bleach solution

    Cleaning mold with bleach solution.

  • Plumbing Leaks: Examine pipes for leaks and insulate if needed.
  • Blocked Gutters: Keep gutters and downspouts clean.
  • Foundation Leaks: Channel water from downspouts away from house.
  • Basement Leaks: Examine basement for leaks and repair if necessary.
  • Water Under House: Check crawl space for excess moisture, and apply black plastic to ground to reduce humidity.
  • AC Drain Leaks: Be sure HVAC units drain properly and that drains are not clogged.
  • Ductwork Condensation: Inspect HVAC ducts for excess moisture. Repair or replace the insulation around them if wet.
  • Air Filters: Use a high quality air filter with HVAC units, and change it regularly.
  • Bath Vent Fans: Install bathroom fans that are vented to the outside. Run them during—and for 15 minutes after—showers.
  • Air Circulation: Open doors and windows during dry weather to increase air circulation.
  • Indoor Humidity: Keep the humidity in your home between 30 and 50 percent. Check it with a humidity gauge or moisture meter and use a dehumidifier to lower it if necessary.
  • Vent Gas Appliances: Make sure gas and kerosene heaters and fireplaces are properly vented to the outside to reduce the amount of moisture in the air.

Sizing an Air Conditioner to Reduce Humidity

When replacing your central air conditioning unit, be sure it is sized properly for the house and climate. While an oversized unit will cool the house down faster, it won’t remove as much moisture from the air. You might also consider adding a dehumidifier to the central system if you live in a climate with high humidity or use a portable model for problem areas.

Mold in kitchen after hurricane

Mold in kitchen after hurricane.

Hidden Problems

If your home still smells moldy or members of your family are having health issues, there could be a hidden mold problem. Mold can grow unseen under wallpaper, dry wall, ceiling tiles, and in heating and air conditioner vents.

If hidden mold is suspected, have the house inspected by a professional. If you think there might be mold in your HVAC system, do not run the unit until the problem has been solved.

Though mold will always be with us, a little diligence on your part can help keep it in check. Prevention and early detection are important, so catch it early and you’ll breathe easier.

Further Information



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34 Comments on “How to Prevent and Remove Mold in Your Home”

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  1. Ray Says:
    November 17th, 2007 at 12:05 am

    Another place where mold can grow for Northern viewers is in a closet that is on an exterior wall(not proper building practice). And mainly because of the pack rat tendency of people to stuff the closet full, against the cold outside wall, Resulting in no air circulation and a higher humidity level.

  2. John Cannamela Says:
    November 19th, 2007 at 8:16 pm

    Mold need water and food(wood,paper).Water comes from not only leaking pipes and or rain leaks, but condensation.
    Condensation can be caused by uninsulated area which allow the air to cool and condense -such as a cold water pipe behind a wall or showers and baths. The moisture can condense on light fixtures etc.The point is that water comes from the air in many ways.The growth that occurs usually is in a cold damp place.So keep things insulated and vented .If you have mold and get it removed,make sure you fix the reason it(mold) grew there in the first place.

    http://www.infraredsurvey.com

  3. Greg Says:
    July 2nd, 2008 at 8:34 pm

    How do I remove mold & mildew from my vinyl siding, I seen a brief demo on the weather channel, however, I only seen the last few seconds. What was the mixing of the solutions?
    Also, I believe I have water leaks within the walls of my home. I’ve had the builders return a few times and they assured me that it is the pipes contracting and expanding. I still hear what sounds like water leaking even when no one is using any water source. The problem I have there’s no access for me to inspect for water leakage. The house is a 2003 ranch with basement, that has no crawl space nor anyother void that I can get into to conduct checks. Any suggestions?

  4. Official Comment:

    Ben Erickson Says:
    July 8th, 2008 at 1:44 pm

    Greg,
    To remove mold from vinyl siding, spray on a solution of 1 part bleach to 4 parts water with a little detergent mixed in to make it stick better. Let it sit for 10-20 minutes then hose off. As far as the water leak goes, monitor your water meter and see if it changes when no water has been used.

  5. Greg Says:
    July 11th, 2008 at 6:04 pm

    Thanks Ben

  6. Shelley Lambert Says:
    July 25th, 2008 at 6:27 pm

    I have a reoccuring problems with mold in several spots in our house, particularly on the ceiling in the master bedroom. There is some condensation buildup overnight, and this room is shady in the morning. To try to counter this we open up windows and ventilate as much as possible, but the mold continues to return. I have cleaned with a mixture of bleach and water to no avail? Do you have any other suggestions to try and fix this long term (should we use a dehumifier at all?).

    Thank you very much.

  7. Mike Abe Says:
    November 8th, 2008 at 12:13 pm

    I just saw your program on going green. You had a segment on removing mold using a non-toxic product. I missed the product’s name. Instructed to go to your web site for more information. What is the non-toxic product’s name to remove mold?
    Thanks!

  8. Janet Robinson Says:
    November 8th, 2008 at 3:00 pm

    Janet says:November 8 2008 We have a problem: When I do laundry I get dizzy when the machine empties out and spins and also how do you find a broken vent pipe in the wall if that is the problem. Thanks

  9. Official Comment:

    Ben Erickson Says:
    November 10th, 2008 at 5:41 pm

    Hi Mike,
    It’s called Concrobium and is available at The Home Depot. I rented their fogger and used it to fog the crawlspace under our house. Find out more about it in our episode article (678) How to Go Green on a Budget

  10. harry griser Says:
    December 12th, 2008 at 8:09 am

    Danny,

    I have green mold on copper pipes underneath the sinks in my vanity in bathroom. Do you have any suggestions on how to clean these up.

  11. BETTY ADAIR Says:
    April 29th, 2009 at 12:36 am

    I HAVE A PAVER BLOCK PATIO.THIS YEAR WE HAVE GREEN MOLD IN SOME SPOT OF THE AREA.WHAT CAN WE DO TO GET RID OF THE MOLD.I KNOW THAT BLEACH KILLS MOLD,BUT WILL IT HARM OR DISCOLOR THE PAVERS?PLEASE CAN YOU HELP? THANKS

  12. sylvia french Says:
    June 7th, 2009 at 6:07 am

    i watched your show sun am re placing plastic in your crawl space.. and topping it with a substance.. was it foam?
    what is the reason for the topping.. other than holding
    the plastic in place.. i would appreciate your answer..
    we have a crawl space.. and need to make it as safe as
    possible.. thanks.. sylvia 6-7-09.. morning show at 5:30am

  13. sylvia french Says:
    June 7th, 2009 at 6:09 am

    i want to know what topping was placed on the black plastic
    over the crawl space.. sun 5:30am 6-7-09.. thanks

  14. Official Comment:

    Ben Erickson Says:
    June 8th, 2009 at 8:03 am

    The topping put on top of the black plastic in the crawl space in the Safe at Home episode was a layer of clean, dry sand. The purpose was to hold the plastic in place, as well as to absorb any excess moisture caused by condensation.

  15. JAN BONK Says:
    March 26th, 2010 at 9:12 am

    We have a large patio made of patio blocks, and have quite a bit of mold between the blocks. I am afraid to use the powerwasher on it for fear it will dislodge the blocks. What would you recommend for getting rid of the mold?
    Thanks, Jan

  16. Official Comment:

    Ben Erickson Says:
    March 29th, 2010 at 9:07 am

    Hi Jan,
    If the stuff between the cracks in your pavers is moss, you might want to try a weed killer like Roundup on it.
    If it’s mold, I would mix up a solution of 1 part bleach to 4 parts water with a bit of detergent added in a pump up garden sprayer and spray it on the cracks. Test it first on an out of the way spot to see if it changes the color of your patio blocks.

  17. Tamera Says:
    July 16th, 2010 at 11:28 am

    We had a house built last year and yesterday I noticed that some of the hvac vents were not blowing any cool air. So I went into the crawlspace to check it out and found a horrible problem. All the insulated flex vents were full of water and so heavy they fell off the main trunk line. Also there is mold growing everywhere. I can see of the walls are wet and one of the floor beams is soaked. I went ahead and cut just through the plastic covering to the insulation on all lines just to drain the water so I could connect them back up as we live in the south and have to have AC. I also noticed the builder never sealed the area between the house and the Heatpump outside so there is a big gaping hole that any animal could crawl in and after seeing a mouse in the crawl space they obviously have been. I have a 2-10 warranty, but have no idea what is covered and what isn’t and with past dealing with my builder after closing to fix a few things he has not been at all helpful. He was great before the closing, but as soon as he got paid that ended. I don’t even know where to start.

  18. Official Comment:

    Ben Erickson Says:
    July 17th, 2010 at 12:33 pm

    Hi Tamera,
    It sounds like you have a serious problem on your hands that will probably take professional help to solve. Start by determining if the water in the HVAC ducts is condensation or from standing water in your crawlspace. If the crawlspace itself is the problem, which it sounds like it is, you’ll need to stop the water from coming in, dry out the crawlspace, treat the area for mold (you can rent a fogger from The Home Depot to mist a product like Concrobium in the crawlspace under your house to kill the existing mold), then completely cover all the ground under the house with thick black plastic to keep moisture from the ground from coming up. You may also need to install vent fans in the foundation vents to remove the humid air from your crawlspace, or seal up all the vents and install dehumidifier in the crawlspace to lower the humidity level.

  19. Sasha Says:
    October 7th, 2010 at 11:56 pm

    One effective way to combat mold problems is by the use of desiccants like Silica Gel. These are the same small sachets you find in packaging of various products like electronics, garments, etc.

    Silica Gel works by absorbing the moisture in its surrounding area. For most mold challenges, it does the job pretty well. Small sachets cost less than a dollar. It truly is a cost effective way of protection from moisture.

  20. Dave / Kayla Says:
    December 5th, 2010 at 7:24 am

    please help.

    we just bought our first home, yesterday we put shrink plastic on the very leaky window(s). All of them this morning had condensation on the room side. One of the windows had enough condensation to form a small pool of h2o. For this winter how do I solve this? We live in northern Ontario Canada. Thank you in advance for your input.

  21. Official Comment:

    Ben Erickson Says:
    December 5th, 2010 at 11:08 am

    Hi Dave and Kayla,
    Given that you have single pane windows that do not seal tight and are living in a cold climate, you would have had a lot of condensation on the inside of your windows with or without the plastic, and should have less on the plastic than you would have had on the glass. Two reduce the problem (I doubt you can cure it without replacing the windows) requires a two-pronged approach: (1) Seal up the windows as much as possible by either caulking them shut (if you never open them); by tightening up the window weather stripping around the sides, where the frames meet, and sill; or by putting up storm windows on the outside. (2) Try to reduce the humidity inside your home. Read our article on How to Cure Sweating Windows to find out more.

  22. robert Says:
    December 19th, 2011 at 9:45 pm

    I have read many places that you should NOT use bleach, what is the right thing to use/

  23. Tim Says:
    January 11th, 2012 at 9:58 am

    Killing and cleaning the mold is one thing. Finding and controlling the source of moisture is another key factor. However, in places like HVAC systems where moisture is a by product of the system, CONTROLLING the mold growth is very important. If you don’t, you can clean it with bleach or other cleaner all you want, it will come back. In this case using an EPA registered Mold inhibitor every few months can keep you and the people in your house or space safer…oh and don’t go out and buy a mold cleaner, it won’t do the job. Check the EPA website for approved chemicals.

  24. Jessica Coyle Says:
    January 29th, 2012 at 6:29 am

    I just put away my Christmas decoration and discoverd green mold on my attic ceiling. This was not there in November. We have had a very rainy winter and it seems more moist then usual up there. I’m not sure if there’s a leak, but in October we had sealed up some spaces in the roof ,and I don’t have any vents or fans up there. I do have a window. Should I open the window or would it only add to the problem due to the damp conditions outside? Trying to figure out what I should do first? Intall proper ventilation and then spray with bleach and water? WIll the mold go away on it’s own with proper venitlation and what type of ventilation would I need? Soffit and ridge vents and a powered fan?? Thanks for your help!

  25. Alisha Says:
    March 18th, 2012 at 9:03 pm

    I have a storage shed containing all of my furniture. My leather lounge suite is at the very front of the shed (just inside the door) and is now covered in green mold. We have had a very wet summer which has created a havean for mold to grow. I know what to do to clean and treat the leather lounge suite however, I need to know what I can do to prevent mold growing over all my furniture. At this stage it only appears to have grown over my lounge whcih is at the front of the shed closest to the door, the rest of the furniture is at the very back of the shed and doesnt seem to have been affected witht he moisture.

  26. Dave Baird Says:
    July 7th, 2012 at 1:09 pm

    Danny, I was watching your daughter’s first home bathroom renovation and noticed she had a mold problem. We too have a mold problem on the ceiling. How did you get rid of this problem? We have green board around the shower and a ceiling fan vented outside, but the mold is back even after using Kilz. What can we do to get rid of the mold and prevent it from returning? We also can not put in a window.

    Thanks, Dave

  27. Ric Causey Says:
    August 17th, 2012 at 9:33 pm

    Danny, I have an ac outside drain pipe(floor level) upper drain lines stopped dripping, that is continuously leaking water. I’ve had my ac man blow out lines in attack, made sure all sink drains are operating but still water leakage. Should we check the coils? What’s causing this?

  28. Rommie Rascoe Says:
    August 28th, 2012 at 4:21 pm

    removed laminate floors in the house and the concrete had moisture on the floors when it rain the water run down the house and it is coming in the house help. thank you

  29. Sara Leal Says:
    August 29th, 2012 at 3:19 pm

    We have a 26 year old house that has a 20 foot vaulted ceiling in the living room with 2 hollow wood beams. We have a heat pump with air conditioning which we run all the time. The beam located at the highest point of the ceiling has grayish looking mold. The beams were stained a cherry finish. We’ve not had any leaks from the ceiling or any leak stains to indicate a leak. We recently changed out our heat pump & a/c with a new system. We’re not sure if the mold started before or after the new system. We live in south Texas so humidity is a way of life. Never had this problem before. At this point, we’re not sure what to do next. Help!

  30. nash Says:
    October 26th, 2013 at 6:40 pm

    we had a fridge leak that damaged kitchen cabinets and have to replace them. what can we do to protect new cabinets from future leaks before installing them?

  31. Richard Says:
    December 18th, 2013 at 11:18 am

    I have a little problem.

    We have a house that was closed up for about 9 months, with the AC on about 74. In the south. By a lake. With high humidity.

    When we opened it up there was a lot of mold. Mostly, if not completely, the green kind. All of the doors are stained (with wood stain) but not sealed. The mold is on them (although mostly around the edge of the doors), on the fake-wood panellig, on the furniture (fabric sofas and chairs and a leather easy chair), and on other ‘unfinished’ wood. I am sure that it is in the ducts of this 2-1/2 story house, too.

    It does not seem to be on the sheetrock (and it isn’t really that bad on the fake-wood panelling), the kitchen surfaces and appliances, and maybe the carpet (although I just can’t imagine that it isn’t). It isn’t in the attic spaces (two small areas on each side of the 2nd floor) either.

    We have deployed Damp-Rid throughout the house.

    We don’t have any water problems. I figure the water that the mold used was from the condensation on the windows from the AC.

    What should I do?

    Thanks!

  32. Ken stypinski Says:
    January 8th, 2014 at 7:19 pm

    Just purchased a 50 yr old home. Mold found on
    First floor level around floor. I have cut out the drywall 4 foot up, repaired the water source, and have had the mold tested. Testing results were 60/70% chaetomium, 5/15% cladosporium! and 5/15% bacterial matter. I have used borax mixture, to clean all surfaces around the area. The drywall above 4 feet shows no sigh of mold. What else do I need to do to be sure this is a healthy house?

  33. Dana Says:
    July 10th, 2014 at 7:34 pm

    I have a white like chauk substance on the floor in the cold storage.We have never used it as a cold storage.It has been closed up for years.It doesn’t seem to be spreading But I can’t get rid of it

  34. Edna Hoey Says:
    July 28th, 2014 at 1:20 pm

    HI…. we live on the lake,therefore we could not put a basement under, we have a 4′ crawl space with cement walls . Ontario has been blessed with Rain & more Rain now we have water under the house in the crawl space I had put down 3 layers of plastic which i AM IN THE PROCESS OF REMOVING. what DO i DO WITH THE REMAINING ODOUR & DAMPNESS!! THE FLOOR(??) IS NICE BEACH SAND and wet!!! please help!!!!!

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