Keep It Dry. Keep It Safe.

Include This, Exclude That

Plans for finishing a basement are typically filled with lots of stuff to include. Maybe you want to include a media center, fitness studio, or a basement apartment for an aging relative.  These are important items to consider but even more important is what you need to exclude.

Moisture.

To help you do this you need to manage:

• Surface water
• Ground water

You have to admit, it's a small list, and if ignored or overlooked, the negative consequences for you, your family, and the health of your home are huge. Ensuring the exterior of your basement walls and floor slab are as dry as they can be is a big step in the right direction.

Your Mission - Impossible

Considering how impossible it is to keep your foundation walls and floor slab absolutely free from being exposed to wet or damp earth, wind driven rain, sprinklers, melting snow, or other interesting sources of water, accept the fact your foundation walls and floor slab will always be moist or contain some amount of moisture.

This means you also need to provide your walls and floor slab the opportunity to dry out, somehow.

That's Interesting

Enough talk about the exterior.

You've done what you can to manage surface and ground water to the best of your ability.  Let's take a look at the interior now. Are there major sources of moisture you need to manage there?

Surprisingly, enough, there are. There is one huge internal moisture source in your home you've probably overlooked and is a major reason you may have a moisture problem, if the bulk water systems are properly managed.

This major source of moisture is: air.

Unfortunately, because air is moist:

• Cold surfaces will form condensate when exposed to warm moist air
• Air is warmer than your concrete foundation wall
• Air is warmer than your concrete floor slab

So now you not only need a strategy to manage exterior water, but somehow prevent warm moist air from coming into contact with cold surfaces too.

There Is A Way Forward

Don't Do This!

How do you do that?

Simple, use thermal insulation.

How you implement or build this system this will either be a good thing or a disaster.  In other words, there is a right way, and many different wrong ways to do this, and it's up to you to decide which method to use. Fortunately for you and me people have made it their professional career to figure this out for us.

Unfortunately, most of the contractors or renovation "experts" are not those professionals which means you're likely to be told how to do things the wrong way, like the way this basement in the photo is being finished.  The end result of this project is you end up with a warm damp basement making you and your family sick.

Your next step is to discover what materials and methods are needed, how they need to be installed, and how to minimize or eliminate warm moist from contacting the cold surfaces of your basement's foundation walls and floor slab.

Mold and Your Basement

There is a serious disaster in the making that is going to impact the majority of homes with finished and/or insulated basements. If you are considering finishing your basement, moving into a basement apartment, or are buying a home with a finished basement, you need to sit up and take notice.

You may be putting your health at risk.

"Fiberglass batt insulation, 2X4 wood or steel stud framing, and a poly vapour barrier is commonly used practice for insulating basements throughout Canada.  This however is a recipe for disaster."  This isn't just hype.

The U.S. Department of Energy has published a short article and describes recommended basement insulation systems to use, and they mention moisture problems are "compounded when an impermeable vapor barrier such as plastic is used on the interior because it will trap moisture in the wall."

This is unfortunate because most, if not all, new home construction in Canada since the mid 1980s use the fiberglass batt and framed wall or blanket insulation system featuring a well sealed 6 mil polyethylene vapour barrier installed on the warm side of the wall assembly.

The result of this construction methodology is moisture wicking through your foundation is trapped inside the insulated framed wall assembly. Due to the low drying potential of the wall assembly, mold starts to grow.

If you think your home insurance policy is going to come to the rescue for you, home insurance policies "typically do not cover water damage caused by 'maintenance' problems. These include slower, ongoing problems like continuous water seepage or repeat leaks, ongoing humidity problems, problems related to your landscaping or drainage on the property, or condensation" says Karla Kant in her article "Home Insurance Guidelines: Mold Facts and Coverage".

The "The American Society of Home Inspectors estimates that 60% of U.S. homes have wet basements. Even well built and sealed basements that would not have mold under normal circumstances can develop mold growth from high humidity" says Robert G. Miller, Forensic Construction Expert.  You can read more here about Basement Air Quality.

"Mold occurrence in new homes has become so endemic that builder's liability insurance coverage limits the insurance carrier's liability to a few thousand dollars, if it covers mold issues at all" says Dr. Richard A. Wolfe, in his article Mold Occurrence in New Construction.

The conclusion I make from having read the information provided in these articles is managing moisture and how it impacts the building is serious, because if ignored, the consequences to you, your family's health, and the health of your home will be disastrous.