Air Management. Water Management.
Do you want a home that is durable and resilient? Do you NEED a home that is healthy? How about comfortable?
Do you know what it takes?
It takes an effective plan to manage water and air. (Notice I said MANAGE and not PREVENT. ) Think of a toddler—have you tried to manage one? Have you tried to control one? Which was more effective?
Now that we’re on the same page about management, what does it all MEAN??? It means that your building enclosure plan needs more attention than your countertops. Why? Because…
“If it doesn’t last, it doesn’t matter.”
Did you know that leakage of air will cause about 90% more transport of water through your assembly than vapor diffusion?
Do you know what vapor diffusion is and do you know what drives it?
Vapor diffusion is the movement of vapor through building materials and through your assembly. It is the movement of water vapor molecules through porous materials as a result of vapor pressure differences.
You might be thinking,
“BUT I DON’T WANT MY BUILDING ASSEMBLIES TO GET WET AT ALL!
-You
As one of my wise Certified Passive House Builder instructors said,
“Physics will always beat out chemistry”
That means that it’s WHEN not IF….your assemblies will see water in some form—whether that’s bulk, vapor, snow, ice, etc.
For example, let’s say it’s a hot/humid day in Texas. No surprise there.
Since hot air wants to move to cooler air, we know the vapor from outside wants to drive towards the inside.
If there was a compromise in your air control layer (and since we know that water uses air as a method of transport), you could see 90% more vapor coming in to your assembly via that hole or channel than if it were just traveling via diffusion through the materials.
One of the big secrets (well, maybe not a secret, but definitely a key) to healthy building assemblies is that their drying exceeds wetting. Are you seeing what I’m seeing?
Did you get your assembly design right to allow all that moisture a place to go to dry? Did you think through climate considerations? Permeability of your material selection? Eliminating thermal bridges (which can cause condensation)? In addition to material selection, are you paying attention to how the materials are installed and integrated?
Maybe not. Maybe so. But one thing we do know for sure is that your assembly design shouldn’t be left to chance if you expect any of the following:
a forever home
a healthy home
a comfortable home
a home that supports your health and wellbeing
a resilient home
a durable home
A healthy home is built from the outside in. Now that you have the right attention on your assemblies, we can start looking at those pretty countertops.
Did you like this bite-sized BS (building science) soundbite? Shoot me an email (cristina@conscioushealthyhome.com) or connect with me on Instagram (@conscioushealthyhome) and let me know.
Stay conscious and curious, my friends.
♥️C
