KILL MOLD: Expert Advice on Getting Rid of Mold and Staying Healthy


Most people are afraid of household mold and that’s a good thing. Mold can sometimes be dangerous, so it’s wise to treat mold with caution when it’s discovered in your home. The trick is understanding the seven steps behind highly effective – and safe ways to kill mold on your own. There’s a lot of confusion about this, but there doesn’t have to be.  The DIY details are below, and if you’ve got mold you should read them. Want quick info to get you going? Watch the video here.

Kill Mold Step#1: Size up the situation

Let’s say you’re tearing out an old basement, or working in an attic somewhere, or cutting into a wall before adding in an addition. Homeowners everywhere discover mold all the time in ways like this. The question is, what are you going to do about it?

The main issue is how big and bad the mold growth is. With the proper know-how, precautions and the treatment strategies I’ll show you here, go ahead and tackle any situation up to the size of a few sheets of plywood. If the moldy area is bigger than this, or if it seems to be associated with some kind of sewage leak, consider calling in a mold abatement professional.

Kill Mold Step#2: Eliminate the Moisture Source

Mold never appears without moisture. That’s why you always need to start your work by finding and drying up the water causing the problem. Liquid water is easy enough to spot, but most hidden household mold is probably due to condensation or some other form of water vapor. You’ll almost always find mold in the fiber insulation stuffed into the rim joists where basement ceilings meet outside walls in cold climates. Basements and crawl space walls and floors are also a common breeding ground for mold, but don’t make the mistake of thinking this is always because of a lack of ventilation. Fresh air is always great and necessary, but not when it’s warm and humid outside. The leading cause of mold and musty basements and crawl spaces is ventilation during hot summer months. When warm, moist, humid outdoor air makes its way into a cool basement, water condenses out, kickstarting the mold growth process. There are a thousand more possible sources of mold inducing moisture, but you get the picture.

Kill Mold Step#3: Make Removal Decisions

Not all moldy surfaces should be treated . Sometimes tearing out moldy materials and replacement is a better strategy. Moldy drywall, fiber ceiling tiles carpets, wood paneling and other non-structural materials are best removed rather than decontaminated. Just don’t be an idiot about the work. Not all mold is dangerous, but how do you know? That’s why you should always wear a HEPA rated respirator when dealing with moldy areas. Your body is pretty important, and there are certain kinds of molds that will cripple you for life if you’re not protected.

Kill Mold Step#4: Dry the Area

Depending on the time of year, different drying strategies make sense. In wintertime adding heat to the situation makes a huge difference. The warmer the air is, the lower its relative humidity. And air with a low humidity is hungry to dry up wet areas quicker. Just don’t use any kind of propane heater for the work. Burning propane gives off tons of moisture which will make the air wetter than it was when cool, not drier. And while it doesn’t sound like much, air circulation with simple household fans really boosts drying action. Just be patient about it. Don’t rush ahead and work with a damp situation just because it suits your schedule.

Kill Mold Step#5: Get Rid of the Organisms

Bleach Is the first thing most people reach for when it comes time to nuke the mold in their life, but this is a mistake. There are three reasons why. First, bleach is actually only minimally effective when it comes to killing mold, especially mold growing on porous surfaces. That’s because bleach doesn’t have the ability to penetrate deeply enough into wood or concrete to kill the hidden roots of the mold that are growing below the surface. Another issue with bleach is that it makes surfaces lighter in color. This isn’t always a problem, but why risk making matters worse with spatters of light color where they’re not supposed to be? And finally, bleach stinks and is bothersome to some homeowners, especially when it’s used over a large area.

The government is involved in just about everything these days, including assessment of how well commercial mold killing products work. That’s why you’ll find registered fungicides on the market. Even though you’re probably not killing fungus, a registered fungicide is what you want to use for mold. The most widely available, non-toxic registered fungicide in North America right now is Concrobium Mold Control (; 866.811.4148) It’s an odorless liquid that kills mold and mold spores by mechanical action, physically crushing all parts of the mold organism as it dries. This explains how something that’s non-toxic can still kill a tiny organism like active mold and mold spores without hurting people. I’ve used this stuff before and it’s as pleasant as water. That’s one reason it’s become so popular with mold abatement professionals. It’s even thin enough to run through an electric fogger for treating really large areas, if you opt to do that.

Kill Mold Step#6: Stop Mold from Coming Back

Concrobium Mold Control is also a proven fungistat, which means it inhibits mold regrowth, too. That said, it’s not magic. If areas of potential mold food do get moist again and stay wet, mold will grow back eventually, no matter what you do. That’s why you’ve got to look towards boosting the right kind of ventilation, while also eliminating places where wintertime condensation can occur. Most of this is very simple – ridge vents on roofs, keeping soffit areas open and free from insulation, dealing with basement leaks – but other mold problems aren’t so simple. The biggest single cause of mold in homes that get cold weather is insufficient wintertime ventilation. This accounts for everything from the mold growing along the bottom of windows, to moldy exterior wall corners and even internal mold growth within walls.

Even though building codes almost always under emphasize the need for mechanical ventilation, a heat recovery ventilator is an excellent option, especially if the renovations you’re doing will be tightening the house up with new windows and air sealing strategies.

Kill Mold Step#7: Eliminate Mold Stains

This isn’t always as easy as it looks. Mold stains can be almost impossible to get off with a scrub brush, and while bleach, hydrogen peroxide or oxalic acid all work to remove stains, they also lighten the colour of surrounding surfaces. The best option I’ve found so far for removing mold stains is a product called Mold Stain Eraser. It’s a white powder that you mix with warm water and let sit for 10 minutes before sloshing onto the surface. Occasionally you might need to do a bit of scrubbing after the solution goes on, but most times it simply removes staining all by itself. And somehow it does this without lightening surrounding areas at all. I’ve even had excellent results using this product to remove grey weathering from exterior wood, without getting rid of the underlying woodgrain.

Learning to control mold effectively and to explain how it’s done doesn’t take a long time, but the health value is pretty high. Kill mold where you find it, boost ventilation, then see how easy it is to  prevent mold from ever coming back.

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Posted on September 3rd, 2017

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