New home construction and mold?

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This is something we have seen more and more in recent years in the Charlotte area- mold formation in the crawlspaces of brand new homes. We are literally seeing it before the rough plumbing and electrical are completed in some cases. But why?

The main contributor in today’s residential construction relates to our current building techniques. Our homes are built air tight (or close to it). Tongue and groove subfloors, home wraps, foam sealants, dual-pane windows, insulated doors and vapor-taped exterior seals on openings are creating environments that do not allow free-moisture exchange via, what is known as, the “stack effect”.  If the vapor cannot ventilate vertically through the home, it becomes trapped in lower areas like the crawlspace or basement; raising wood moisture and humidity levels.  This can rapidly lead to fungal growth on the organic substrate.

While this “tightening” of the construction of our homes serves to benefit us in energy savings and comfort down the road, these methods do us few favors in terms of providing for fresh air exchange with the outside in the short-term, which can be vital in drying out a crawlspace to prevent mold spore proliferation in the first place.

If you’ve had the unpleasant privilege of dealing with a mold remediation bill on a brand-new home, you will know what a frustrating and profit-consuming thing this can be. We have prevention services that can eliminate mold growth as a possibility, while providing a fully-transferrable warranty against mold growth in the property so that your buyers are getting piece-of-mind with their purchase.

And all of this can cost far less than you might think (certainly less than a mold remediation bill.)

We have seen many construction projects where this has occurred.  But, be assured, there are preventative measures that can be taken. We are in the business of providing these solutions to our customers, which include builders, renovators, investors, and real estate professionals alike.  We have a range of vapor retarding solutions, ventilation systems, dehumidification appliances and even sealants or coatings that can provide a complete mold-proofing barrier over the wood material, insuring that fungal proliferation will not occur.

Reach out to us at Intellivent to learn more about mold removal in Charlotte.  We are happy to help you make sure the first thing living in the new home you’re building is the person buying it and not mold.

 

Crawlspace humidity: Not just a summer problem.

 

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Here in Charlotte, there exists a notion that elevated moisture and humidity problems aren’t prevalent in the winter.  This is a myth.

Even well-maintained homes can have mold moisture issues in the crawlspace area. In the winter wet season, humidity in air still exists and cool air particles hold less moisture content before condensation occurs.  This means that a crawlspace can still have significant moisture problems regardless of the season.

Also, heavy precipitation that flows back into a crawlspace due to grading can add moisture to a crawlspace environment that does not have the ability to evaporate or shed it.  This may lead to standing moisture which can communicate, via evaporation, to the wood structure above, raising moisture content of structural members over time. This will eventually lead to mold, rot, termites, etc..

It is important to know the condition of your home’s crawlspace year-round by either visual inspection or a site visit from a professional.  Regardless, one should not assume that they are safe from the effects of crawlspace mold, moisture, and damage because it’s not hot and humid outside.

The winter season definitely has it’s own set of crawlspace mold and moisture challenges, Charlotte.  It pays to stay on top of what’s down below.

 

Mold, Moisture, and Your Crawlspace

By Bill Mitchell
Originally written June 23, 2017

It was an unusually humid, warm, and very wet Spring in North Carolina. Now, officially two days into the Summer season, there’s very little sign of things letting up. It has rained in the Charlotte area every day for the last 10, and there have already been 3 “named” tropical storms. So, we’re off and running.

Make no mistake, all this wet weather makes for a potentially problematic environment for the traditionally vented crawlspace under your home.

The water table is at capacity in most areas. The ground is full- with so much precipitation, it’s literally holding all the water it can. This includes the ground beneath a home. As the soil releases this moisture away (in the form of evaporation), that moisture releasing into a crawlspace has nowhere to go. Damp air becomes trapped against the structural members of the dwelling and compressed into the crawlspace with no way of ventilating itself, raising humidity and causing wood moisture values to elevate. Once the moisture content of the wood gets to 20%, mold will form quite rapidly.

Compounding this problem is the presence of colder air in the crawlspace. A crawlspace will typically be a constant 65-75 degrees in summer. We all know that our outside temperatures in summer are much higher than this, and humidity values are consistently through the roof as well. Albeit under the roof, the crawlspace and it’s environment are still under constant attack from the elements. It’s a fight against nature all of the time.

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This diagram illustrates the what happens in the crawlspace when we cool air that is 80% humidity just FIVE DEGREES! And, don’t think of this diagram as theoretical, it’s something that actually happens constantly beneath our homes.

(Another neat tool to see how a crawlspace is affected by humidity and temperature can be found here. You can see just how quickly mold can form in a space when temperature and dew point are not effectively managed.)

“So what do we need to do?”

At a minimum, a home needs a good vapor barrier. What’s a “good” vapor barrier? A .6mil poly plastic (we prefer .10mil) covering 100% of the crawlspace soils is a must. No matter what a salesperson or contractor will try to tell you, the thickness of the plastic is irrelevant in keeping out moisture. A product’s thickness is only important as it speaks to it’s durability. The thicker it is, the tougher it is and, therefore, will hold up better against wear over time.

A “good” vapor barrier should also be staked to the ground to prevent movement as you or workers crawl in and out of the crawlspace on the material. The seams should also overlap 6″-12″, where possible, to prevent unimpeded evaporation of ground moisture through these joints and into the space.

But, often, a “good” vapor barrier is nowhere near enough. And, ideologically, this is where we tend to part ways with some of our competitors in the industry. We don’t like to seal a space. Components of a crawlspace structure are meant to breathe. The house requires it.

We believe in controlled ventilation of the crawlspace using a proven, engineered system like Atmox. This system utilizes low-voltage fans (using far less energy than large dehumidification units that are essential in encapsulation systems) and a computer controller that measures dew points inside and outside of the home to decide when environmental conditions are favorable to import dry, healthy, and helpful air. Vents (and other penetrations or openings), not in use by the Atmox system, are sealed off completely, creating a tight space that keeps the free exchange of damp, humid air from outside the house to a bare minimum. This keeps the crawlspace structural components too dry for mold to form, and keeps the environment healthy and stable consistently over time.

As an added benefit, the import of fresh air into the space reduces or eliminates smells and odors associated with off-gassing encapsulation liners or musty odors from the trapped, stale air beneath the structure. Customers with sensitivities to these smells rave about the benefits of bringing fresh air into the house envelope. No more dirt smells. No more musty smells. No more “plasticky”, cat urine smell from the sealed liner.

So, with a “good” vapor barrier on the ground, a controlled ventilation system beneath the foundation of the home, and sealing up auxiliary vent openings and porous air leaks in the foundation, the Atmox is able to maintain the clean, dry, and stable environment that we need in our crawlspace. This adds value to the home and, best of all, can do so for less than half the cost of an encapsulation in a crawlspace.