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How to Remove Mold

Almost every home gets mold. We'll show you how to identify mold and eliminate the small infestations, as well as the big ones that have gotten out of hand.

By the DIY experts of The Family Handyman Magazine

How to Remove Mold

Almost every home gets mold. We'll show you how to identify mold and eliminate the small infestations, as well as the big ones that have gotten out of hand.

By the DIY experts of The Family Handyman Magazine

Step 1: Overview

Mold is a major-league nuisance. It blackens the grout lines in your shower, discolors drywall, shows up as black spots on siding, darkens decks, and grows on and rots damp wood everywhere. Even worse, it can be bad for your health. It releases microscopic spores that cause allergic reactions, runny noses and sneezing, as well as irritating, even injurious, odors.

Almost every home gets mold infestations. The trick is to stop them before they get big and harm both you and your home. In this article, we'll show you how to identify mold and eliminate the small infestations as well as the big ones that have gotten out of hand.

You can easily remove minor mold with ordinary household cleaning products. But disturbing big infestations can be bad for your health, particularly if you are an allergy sufferer or have a weakened immune system. When you discover an extensive mold problem, we recommend that you use the rigorous protective measures we show in Photos 1 - 6, or consider calling in a professional to handle the problem. (Look under “Industrial Hygiene Consultants” or “Environmental and Ecological Consultants” in your Yellow Pages. Or call your local public health department.) And even if you hire pros, read through this article and make sure they follow similar precautions to keep the mold from spreading throughout your house.


A few types of mold are highly toxic. If you have an allergic reaction to mold or a heavy infestation inside your home, call in a pro to analyze the types. Or call tour local public heath department and ask for mold-testing advice.

Step 2: How to identify mold

Mold is everywhere. It's a type of fungus that grows from tiny spores that float in the air. It can grow almost anywhere that spores land and find moisture and a comfortable temperature, between 40 and 100 degrees F. Typically that includes about every damp place in your home.

You can easily spot the most visible type of mold, called mildew, which begins as tiny, usually black spots but often grows into larger colonies. It's the black stuff you see in the grout lines in your shower, on damp walls, and outdoors on the surfaces of deck boards and painted siding, especially in damp and shady areas. A mildewed surface is often difficult to distinguish from a dirty one. To test for mildew, simply dab a few drops of household bleach on the blackened area. If it lightens after one to two minutes, you have mildew. If the area remains dark, you probably have dirt.

Mildew is a surface type of mold that won't damage your home's structure. But other types of mold cause rot. Probe the suspect area with a screwdriver or other sharp tool (Photo 3). If the wood is soft or crumbles, the fungi have taken hold and rot has begun.

If you have a high concentration of mold, you may smell it. If you detect the typical musty odor, check for mold on damp carpets, damp walls, damp crawlspaces and wet wood under your floors, wet roof sheathing and other damp areas. Clean up these infestations right away before they get worse, and see the following photos for prevention measures.

Step 3: Removing large infestations requires precautions—and work!

You can scrub away the surface mold common to bathrooms, decks and siding in a matter of minutes with a 1-to-8 bleach/water solution. But often mold grows and spreads in places you don't notice, until you spot surface staining, feel mushy drywall or detect that musty smell.

If you have to remove mold concentrations covering more than a few square feet, where the musty odor is strong or where you find extensive water damage, we recommend that you take special precautions. You want to not only avoid contaminating the rest of the house but also protect yourself from breathing high concentrations of spores and VOCs.

  • Wear old clothes and shoes that you can launder or throw away after the cleanup work.
  • Wear special N-95 or P-100 respirators, in addition to goggles and gloves.
  • Set an old box fan or a cheap new one in a window to ventilate the room while working. Throw it out when you're done cleaning, because the spores are almost impossible to clean off. Tape plywood or cardboard around the window openings so the spores can't blow back in (Photo 1).
  • Wrap and tape moldy carpeting in 6-mil plastic, and double-bag mold-infested debris in garbage bags for disposal (Photos 1 and 4).
  • To control airborne spores, moisten moldy areas with a garden sprayer while you work (Photo 1).
  • Turn off your furnace and air conditioner and cover ducts and doors to contain spores.
  • Keep your wet/dry vacuum outside when you vacuum (Photo 5).

Moisture damage and large mold infestations go hand in hand. Photos 1 - 7 demonstrate cleaning under an old leaky window where wind-driven rain frequently got into the wall and gave mold a foothold.

You have to open up the wall to get at the mold growing inside (Photo 4). Since you have to repair the wall anyway, don't hesitate to cut the drywall back beyond the obvious damage to find all the mold and let the wall dry out. To avoid cutting electrical wires, poke a hole through the damaged section and locate the wires first. Turn off the power to the outlets before you cut.

If the moisture damage has been neglected or gone unnoticed for long, you're likely to find rot. Where possible, remove and replace soft, spongy studs and wall sheathing. Where removal is difficult, treat the affected areas with a wood preservative (available at home centers), after cleaning the wood and allowing it to dry. Then double up rotted members with pressure-treated wood.

Tips for Mold Prevention

The key to stopping most mold is to control dampness. The worst infestations usually occur in damp crawlspaces, in attics and walls where water has leaked in from the outside, and in basements with poor foundation drainage. Stopping leaks, ensuring good ventilation in attics, keeping crawlspaces dry and routing water away from the foundation are the best defenses.

Mildewcide in paint is usually effective for controlling surface mold in damp rooms like bathrooms and outside in shady areas. Many paints already have mildewcide in them. Check with your paint dealer to be sure. You can add mildewcide, although you might void the paint warranty.

Step 4: Cleanup and repair

Complete the initial cleanup by vacuuming up the debris (Photo 5). Thoroughly clean the wet/dry vac afterward by disposing of the filter and washing out the tank, hose and attachments with the bleach-and-water solution.

After scrubbing the surfaces (Photo 6), simply allow the bleach solution to continue to penetrate the surfaces and dry. Wash concrete floors with TSP, automatic dishwasher detergent or a chlorinated cleaner such as Comet.

Set out dehumidifiers and new fans to dry the now-cleaned areas for at least three days, then check them (by sight and smell) for mold. If you discover more mold, clean again with bleach.

When you're sure the mold has been eliminated, seal the wood surfaces with pigmented shellac like BIN or an oil-based primer like KILZ (Photo 7). Repaint cleaned wall surfaces with a regular latex paint that contains a mildewcide to help stop future mold growth. And keep in mind that if the moisture returns, mold will return.

Removing surface mold

Techniques for Cleaning Surface Mold

Surface molds grow in just about any damp location, such as the grout lines of a ceramic tiled shower. They're easy to scrub away with a mixture of 1/2 cup bleach, 1 qt. water and a little detergent. The bleach in the cleaning mixture kills the mold, and the detergent helps lift it off the surface so you can rinse it away so it won’t return as fast. You can also buy a mildew cleaner at hardware stores, paint stores and most home centers.

Even for simple cleaning, protect yourself from contact with mold and the bleach solution by wearing a long-sleeve shirt and long pants as well as plastic or rubber gloves and goggles.

If the mold doesn’t disappear after light scrubbing, reapply the cleaning mix and let it sit for a minute or two. Then lightly scrub again.

Seal the clean surfaces when they're thoroughly dry to slow future moisture penetration. Apply a grout sealer (available at tile shops and home centers) to tile joints.


Don't mix ammonia or any detergent containing ammonia with bleach. The combination forms a poisonous gas.

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Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

    • Drywall saw
    • Safety glasses
    • Shop vacuum
    • Paintbrush
    • Utility knife
Window fan
Rubber gloves
N-95 respirator
Scrub brush

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

    • 6 mil plastic garbage bags
    • Painters tape
    • Plastic sheeting
    • Bleach
    • Heavy-duty cleaner
    • Shellac- or oil-based primer

Comments from DIY Community Members

Share what's on your mind and see what other DIYers are thinking about.

1 - 19 of 19 comments
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May 14, 4:52 PM [GMT -5]

It is VERY IMPORTANT for people to know that Bleach DOES NOT KILL MOLD!!! It only removes the color so to speak... it will come back in a few weeks, or less. I have seen so many problems pop up from Do it yourselfers... when it comes to MOLD. I had a friend that thought they had a little bit of mold, so they cut a 12"x 12" section out. and hit a mold pocket. What was worse, it was STACHY and they infected there whole home. Instead of spending $ 1,000 on a clean up, they ended up paying over $7,000 to scrub their whole house down.

I wish I had the time to tell all the Horror stories ... Please homeowners, DO NOT attempt to tackle this your self....

March 16, 2:32 PM [GMT -5]

HELP!!! it's been a rainy winter and unfortunately our deck box is full of mold! most of the mold is on tennis racket handles, but there's a little bit on other random places-how do i clean it.. i know i need to wear a respirator and goggles but other than that. is it better to do it on a rainy day or sunny? not sure what to do with all the other things in the box that dont seem to have anything on them..can i just wipe them down??? how will i know it's all gone? THANKS in advance!!! :)

November 27, 11:56 AM [GMT -5]

Along with the DIY suggestions for tools needed, don't forget to wear clothing or Tyvek full body suit and booties that can be disposed of immediately after the mold remediation process. Also use a heavy duty contractors trash bag for disposal of loose items, ie.. drywall, insulation, carpet and pad etc... Twist the neck of the bag and wrap it with duct tape and dispose of properly. Over protection is better than not enough. It's not worth getting sick or causing others to get sick especially kids or pets by not using the necessary precautions.

September 21, 7:54 PM [GMT -5]

Pretty good post. I'd advise people to be careful mixing chemical to remove the mold and safety equipment is a must when doing this. Maybe its better to hire a pro.

August 25, 2:22 AM [GMT -5]

You may easily remove mold, but be precocious use gloves, mask and brush for cleaning. Vinegar or any other bleach product is used to clean mold. Spray vinegar on mold leave it for sometime, then scrub it with brush or cotton cloth, mold will disappear. Make sure that your house must be well ventilated so that it dry the air inside, so that mold will not form in future.

mold remediation great neck

August 25, 2:08 AM [GMT -5]

We can use vinegar or bleach for removing mold, these are Eco-friendly products so does not cause any harm to us. For this spray vinegar into mold and after sometime scrub it with cotton cloth. In future make sure that your house must be well ventilated just to pass the air, so that no moist will occur.

mold remediation great neck

August 13, 5:31 PM [GMT -5]

Unfortunately, this article is filled with incorrect information.
Bleach should only be used for hard, impervious surfaces.
Using bleach on wood or other porous surfaces can actually promote and feed mold through water penetration.
Please do thorough research before attempting DIY mold remediation.
Don't depend on any single source... even reputable sites like this can give bad advice.
Also be sure to read and understand the manufacturer's instructions for any product used.

July 17, 4:08 PM [GMT -5]

MY HOUSE SMELLS LIKE MOLD We have seen it many times. An owner or family goes away for a period of time, whether a few days or a few weeks. They return to their home to find that their home smells like mold. There is no apparent source of water, but the smell is noticeable, and the owner has just concerns regarding the cause. Mold growth requires an event to have occurred. This event may be major and obvious, or something that requires a thorough exam to determine what exactly happened. If the event is substantial, like a broken pipe, hot water heater, or a/c condensate leak, the inspection is pretty quick, and the answer definitive. There may be noticeable water damage and with a dwelling closed up for a period of time, the smell of the resulting mold growth can become concentrated and very noticeable. There are other times, however, when there is no obvious sign of water damage, but yet there is a definite smell of mold. In this case, a more thorough investigation might be required. A moisture meter is typically used to moisture map the building or infrared photography can be used to locate moist, or cooler areas of building components. All this is done to find hidden moisture and mold. Sometimes a leak under a kitchen cabinet might allow water to remain trapped under the cabinets or tile. Sometimes a leak from the outside results in moisture that is contained behind baseboards. Wood or tile flooring can conceal water, and wet carpet from a slab leak might not be obvious. Leaks in A/C ducts could cause excess condensation in ductwork and leak into attic spaces. The investigator is looking for wet material, and the source of the water that caused it to get wet. In each of these scenarios, you may never see the water, but you smell the mold. A qualified restoration company might well find the cause of the moldy smell, but sometimes they are stumped. In this case, you might call a “Mold Assessor”. If a mold assessor is called in for the investigation, he will be looking for all of the above once again, and then probably take air samples from the suspect room or rooms, as well as an air sample from outside the dwelling for a comparative analysis. He might also take a sample from a part of the dwelling that does not have that moldy smell. The object of this inspection would be to determine if you have an elevated airborne mold condition in your home. If an undetermined water leak is suspected, you could call a “leak detection” specialist. Some plumbing companies have the equipment and expertise to do this, but many plumbers use specialists themselves. A very small leak in a pipe is often difficult to find. Sometimes the pipes need to be charged with compressed nitrogen. When this gas leaks through a break in a pipe, the noise is detectible with the use of sound monitoring equipment. Leaks that are difficult to find are often detected using this method. If there is even a small amount of water intrusion into a property, and if the relative humidity goes up, and exceeds 65%, and if the temperature inside the building becomes elevated, there is the potential that a serious mold condition could develop. In such a situation, mold growth could be observed growing on anything organic in the building. Once these conditions occur, the whole property is usually treated for the mold contamination, and many content and porous items may be deemed unsalvageable. Mold can remain dormant in a building for many years, and remain inactive until it becomes wet again. If it remains dry and dormant, it will not smell. The smell of mold is the result of the off gassing of the mold, or fungi, digesting whatever it attacks. The State of Florida now regulates the mold inspection and remediation industry. It is important to know that if you hire a “Mold Assessor” or a “Mold Remediator” to perform services, you should verify their licensing credentials.

June 22, 6:00 PM [GMT -5]

Wow, thanks so much for the tips! That is really awesome! I have been working hard on cleaning ducts. It has a been a bit of a struggle to get the mold out of the duct cleaning. But I have found a lot of place that offer advice. One that has proven trust worthy has been www.ddkductcleaning.ca Does anyone know any other method that could work for duct cleaning?

June 10, 10:10 AM [GMT -5]

We had our deck refinished September 2011 and it looked beautiful - within a month we started to see black spots and now - June 2012 - it looks horrible! I tested a small area with bleach and it immediate looked 100% better - so I guess I have a project to do! This is what I was told:

First - do a test: take a q-tip or cotton ball dipped in fresh household chlorine bleach and apply to some of the black.

1. If the black disappears right away, you have mold on the surface of your stain. That's the best place to have it. You can kill it with a rinse with an oxygenated bleach cleaner. Allow to thoroughly dry. You will need to do regular cleaning to keep it that way. When you apply a maintenance coat of stain down the road, add in a mildewcide to the stain itself that will help prevent future surface mold and mildew.

Would you agree with this remedy? If so, How do I rinse with an oxygenated bleach cleaner. Thoughts??

May 30, 8:44 AM [GMT -5]

RobertSteller and others, we are about to buy a house and mold results just came back as over 10000 particles indoors in the walkout basement. What should we expect the owners to do to solve this problem? I don't mind a little mold, but 10000 is above EPA recommendations and I'm afraid it's in their drywall- how do I know if it's in their drywall? I don't want to cheat the sellers, but I don't want to buy a house that's molding to death!

May 28, 8:51 PM [GMT -5]

OK... I don't know who wrote this.. and I don't care, I am a certified remediation tech. Please use proper process to do this. Do NOT do as the article suggests. This is for someone that is not well educated.. first off the guy in the picture is not wearing proper PPE. using every day clothing and then scrubing mold means you are brining the spores into the rest of the house... so why bother trying to create a negative air with a vaccumme? please go to the hardware store and by a "tyvek" coverall and use a hepa mask not a dust mask.. organic vapour prefered" then buy yourself some nice biocide like benefect or something (made from tyme oils and safe to drink up to 1 cup) clean the surfaces, double bag it and take it though an air lock ( meaning an area with air pulled to the infected area so spours are sucked into the infected area... this is also where when your done you remove the 6$ tyvek coverall...) be smart... AND to assure you.. despote what you say.. bleach does nothing more to moulds then turn them white.. some moulds are not killed byu bleach, and some heavily infected arears require sanding and then cleaning... I had a few beer and found this.. so excuse the spelling.. and good luck..... plkease be smart.. mold in small numbers is not the issue.. but some black spots can mean that on the backside of the drywall, is covered.. all depends on the infestations.... GOOOD luck and GOD Bless...

April 21, 5:43 PM [GMT -5]

Finally, some reasonable advice. Someone NOT treating "mold" with hysteria. Cleaning and removing mold is relatively straightforward and you have even given me some good tips. Sure, there is occasion for professional remediation, but treating every black spot like it's going to kill you is utter nonsense. Thank you for some level-headed advice.

December 17, 8:55 AM [GMT -5]

Interesting post, I am so glad that I have visited your site. Really useful information!

January 26, 4:56 PM [GMT -5]

Like some of the other comments, Bleach is sometimes not the correct answer for some folks that are chemically sensitive. Also Bleach can burn and cause issues that some of the newer green based chemistry will not. For those folks there are companies that are making good mold cleaners without the bleach issues and will also deal with the spores that cause the allegery issues. Companies like EcoDiscoveries and Benefeact are doing excellent work in that area. A suggestion is to google Green based mold cleaners. Bleach can be fine for a lot of folks but I feel that it needs to be mentioned that it is not the only solution to this problem.
Also make sure that you can call and talk with the makers of these products as they will help with making sure that they are used correctly and be willing to work with the DIY market.

December 02, 11:02 AM [GMT -5]

Excellent advice on the protective measures needed to remove the mold, however the idea of using Bleach as the removal chemical on drywall or structural materials is frowned upon in the industry. Bleach is effective in cleaning mold and other organic contamination on hard, non-porous surfaces, but does not effectively clean the surface of wood, carpet, and sheet rock.

Although bleach will kill the mold spores, it will not remove them. Dead mold particles still create allergy problems, and still still cause a failing score on an IAQ test. The dead mold particles must be removed with some type of encapsulation method like a Hydrogen Peroxide based cleaner or manual removal with media blasting equipment. This is the ONLY way to safely and correctly remove the problem.

June 03, 4:53 PM [GMT -5]

Robert Stellar, how would you recommend removing mold from a hardwood floor (small amount recently developed).

May 11, 10:49 PM [GMT -5]


I am a field editor as well as a certfied microbial investigator and certfield microbial remediator. The article suggest do it yourself however in my daily practice I see the disaster peple produce because they read article like this. Often mould is hidden and people get serious health problems because they open walls.
People should not be encouraged to mess with mould.
I am happy to assist with proper tips

April 29, 8:46 AM [GMT -5]

This is really a good project

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