Is winter construction linked to mold?

Is winter construction linked to mold?

In this article I will highlight some important considerations to think about if you are planning to buy, build or have recently purchased a new home that was built during the winter.

Before we dive into the details, lets talk about mold

Mold in our homes is becoming a frequent topic of discussion as we learn more about the damage that it causes, and potential impact on our heath. Much of this conversation leads to the necessary remediation efforts to remove mold when it becomes problematic. The focus is typically reactive.

The next step usually involves figuring out ways to prevent the mold from coming back. I guess it is human nature to learn from our mistakes so we don’t make them again. The more expensive or dangerous the mold issue is, the more we pay attention.

It would be extremely rare for people to ask me if their newly constructed home may end up with mold issues, resulting from the original construction. Home buyers do not seem to consider whether or not their new homes may actually be harboring mold.

As you will discover below, I believe they should be thinking about this, especially since mold is often not discovered until the homeowner begins to notice heath issues similar to mold exposure (allergy or flue like symptoms, dry throat, etc) or they smell a musty or moldy odours. I also think that it might have something to do with our tendencies to be reactive, coupled by the fact that mold is still a mystery to most folks.

So why is mold a mystery?

The sole reason mold exists is to break down dead organic materials in our outdoor environment. So essentially, mold is nature’s recycling program. If we didn’t have mold, we would be walking around waist deep in vegetation and debris.

Mold is a type of fungus and their spores are everywhere, so getting rid of them is not possible. Mold needs moisture, moderate temperatures and a food source (organic material) to live. Aside from the moderate temperatures and food sources, the single most important ingredient for mold to grow is moisture. Remove the moisture and the mold will stop growing.

However, what many people don’t think about or know is that mold is remarkably resilient. It can dry out, and remain dormant for thousands of years, only to start growing again when the conditions are once again ideal.

Mold is also mysterious because unlike plants, which need sunlight to photosynthesize, mold cannot do that, so it must grow in dark areas and often hidden from sight. That is why it can be discovered indoors behind walls, furniture, in crawlspaces, attics, behind shower walls, etc. Unfortunately for us, mold does not know that we would be much happier and healthier if it just stayed outside.

Getting back to winter construction…

Here in the Pacific Northwest, or more specifically Vancouver (which I commonly refer to as “Raincouver”) we live in a rain forest. We get a lot of rain from October all the way through to May – more than ½ the year!

In fact, this year we had record rainfalls in October. According to CBC News, It rained 28 out of 31 days in Vancouver, surpassing the old record of 26 days. November was wet too with 25 days. It’s now December, and we are getting snow. Vancouver snow does not tend to stay around for long, so it causes more wet slushy conditions.

While driving through the city these past few months, I witnessed several homes under construction and piles of wood that were completely saturated from the rain. Not only was the structure wet, the concrete foundation walls were soaked. Considering these circumstances, I would suggest that winter construction is not the ideal time to build a home, especially here Vancouver, Seattle, etc.

As a home and mold inspector, I began to wonder…

With all of this rain, how do we know that the building materials that go into the new homes are not going to become moldy?

In reality, we have to rely on the supplier to send dry materials to the site. Next, the builder must ensure that the construction materials stay dry or below 19% moisture content before they can be used. After all, once the building has been finished (covered by drywall and insulated) there is no way for us to see what is actually going on behind the walls.

In addition, houses are going up faster and faster these days, as there is a lot of money on the line when projects are delayed. As a result, some builders may in fact be pressured to complete the houses as quickly as possible, without taking the necessary steps to keep the construction materials and framing dry.

No matter how tempting it may be, I’m not going to be a “mold prevention vigilante” running around with my moisture meter, testing the framing, piles of lumber or drywall in all of these construction sites before the homes are closed up.

Organic, wet materials can begin to spawn mold growth within 24-48 hours. Along with the other issues mentioned, even if a small area of mold begins to grow before it dries, a seemingly harmless leak, trapped moisture from evaporation or condensation can result in a serious mold problem anytime in the future. This is especially true with newer, tightly built energy efficient homes that lack proper ventilation.

So what is the answer?

Construction during the winter poses some unique challenges for builders as they work through wet, cold conditions. The first step goes back to the beginning of the article. We have to change the way we think about dealing with mold, by being proactive, rather than reactive. This involves understanding the procedures that a builder needs to take in order to protect the framing and construction materials from moisture, throughout the entire building process.

This can be accomplished through:

  • The use of drying & heating equipment
  • Setting up containment areas
  • Installing tarps
  • By frequent moisture testing

These measures can reduce the risk of hidden mold following construction. However, if mold related issues become apparent soon after construction, complications may arise with respect to resolving these issues.

Based on what I am seeing, I think that building a home during the winter (especially in wet climates) can lead to future problems. Taking the precautions to keep the home dry will likely be an expensive undertaking. If you do plan to have a home built in the winter, consider the following questions…

  • What steps are builders required to take to ensure that a building stays dry during construction?
  • Who is enforcing these rules?
  • Do the Homeowner warranty programs cover mold damage in new homes?
  • Are insurance policies are available, and if so what do they include with respect to mold?

At the end of the day I believe that much consideration should be given to this topic, so home buyers will be aware of the potential implications related to the impact mold can have on new homes, our health and pocket book following winter construction.