As most of you probably know, I live in a very cold climate, climate zone 7 in Northern Minnesota (almost Canada). How we build homes up here is different than how my buddies Travis Brungardt and Joe Cook from Catalyst Construction in the Kansas City area build, or how Matt Risinger builds in the Austin, Texas area. A lot of how we build is similar, we all use similar framing techniques and roofing products, but the building science of how we build is obviously much different. This post is about what you need to think about when building in your area of the country, or the world.
This is the most recent climate zone map of the US, sorry, I don’t have one for Canada or the rest of the world. The first step of how you base some of your building decisions is to find your location on this map. Are you in a wet, dry or marine climate? What are the expected temperatures during the summer months? How about the winter? Much of the information will be driven by the code requirements for your location. Everything from insulation levels and window performance to air tightness requirements are listed in the codes based on location. Most are found in the Energy Efficiency section, chapter 11 of the International Residential Code or IRC. There are other sections of the code that deal with climate location, such as foundation insulation for slab edge and frost protected shallow foundations, which are based on the air-freezing index located in R403.3(2) of the IRC. Sometimes finding the information is more work than understanding the code.
So, when you are reading some of my blog posts, be aware that I’m a cold climate construction guy, I understand cold climates much better than hot and humid areas. Be aware, the suggestions I make and what works in my area might not work in yours. Be sure to base your construction decisions on your climate.
As I think you know, I have a big project infront of me and finding your blogs and experiences is a goldmine of information. Thank you!
I live in a hot – cold climate not so far behind yours, in latitude, eastern washington. Our codes require a ventilation space above the insulation, when not designing a hot roof. The code is a default minimum and I have found that building scientists are suggesting more than the code minimum. What I haven’t seen in my research is design information regarding how the chimney affect of rising hot air effects ventilation efficiency, or how insulation levels affect condensation levels as it is known that the higher the insulation rate the more extreme the rate of condensation as the buildings heat decreases in warming the outer sheathing. Nor is it easy to find information on dead air spaces in difficult to ventilate areas where air needs to go around or under roof framing, as in a mansard frame.
My own roof has framing that breaks the flow of air under sheathing, so that air has to spill under frame pieces creating potential dead spaces that ask questions of the design about flow rate versus air volume and detailing like ceiling permeability and the cold-side insulation air barrier. Even a treatment or paint for mildew resistance for inner sheathing and framing is a question.
I am slowly addressing issues like these, and blogs like yours here are an important source of information. I did sign up for the mineral wool insulation that you suggested – thanks!