In a few weeks, I will be teaching my first building science class during a continuing education contractor expo in my area. Continue reading “Building Science-Continuing Education”
Building Science-Heat Movement in Pictures
I’ve talked a few times on this blog about how a home can lose heat in a cold climate. Thermodynamics tells us heat moves from a warm space to a cold one by one of three methods; convection, conduction or radiation. This blog is going to show visually how a structure loses heat by way of several thermal images photographs. Continue reading “Building Science-Heat Movement in Pictures”
Construction Materials-Vapor Retarders
I recently wrote a blog post titled Building Science-Building Shell Layers-Vapor Control Layer. This blog is going to expand on that discussion with information on several choices of vapor retarders. Continue reading “Construction Materials-Vapor Retarders”
Building Science-Building Shell Layers-Thermal Control Layer
Last week we talked about interior moisture drive through the building shell, the vapor control layer. This week we will continue with the building shell layers discussion, number 4 on our list is the thermal barrier. Continue reading “Building Science-Building Shell Layers-Thermal Control Layer”
Building Science – Building Shell Layers – Vapor control layer
Last week we talked about the what makes a house “tight”, the air control layer. This week we will continue with the building shell layers discussion, number 3 on our list is the vapor control layer or vapor retarder.
Continue reading “Building Science – Building Shell Layers – Vapor control layer”
Building Science-Building Shell Layers-Air Control Layer
Last week we talked about the outer most layer in a building, the rain control layer. This week, we will continue with the building shell layers discussion. The air control layer is next on the list. Continue reading “Building Science-Building Shell Layers-Air Control Layer”
Building Science-Building Shell Layers-Rain Control Layer
The next four blog postings are all going to discuss a few of the most important parts of a building, the four layers in a building shell. I’m leaving out the “structural layer”, though it’s the most important part of a house, the other layers are less understood. Continue reading “Building Science-Building Shell Layers-Rain Control Layer”
Building Science-Passing a Blower Door Test
In my last blog, I talked about vapor diffusion and the perm rating. Sometimes it is better to eliminate the polyethylene sheeting most builders in Minnesota are using for both the air and vapor barrier. The problem then becomes passing the blower door test. Continue reading “Building Science-Passing a Blower Door Test”
Building Science-Perm
Builders in northern Minnesota have been using polyethylene sheeting on the warm in winter side of wall assemblies for years. Beginning in the 1960’s, we were taught that the poly would stop vapor diffusion in building cavity, keeping walls dryer. During the 1990’s and 2000’s, building scientists determined that only a small percentage of wall wetness comes from vapor diffusion. So, how does moisture end up inside building assemblies in a northern climate? Mostly by air leaks! Continue reading “Building Science-Perm”
Building Science-R-value
In our northern climate, how quickly a structure loses heat is dependent on three factors, the first is transmission heat loss which includes the difference between inside and outside temperatures, called the delta T, and the resistance to heat flow, or R-value of the building assemblies. Continue reading “Building Science-R-value”