Testing-Failed a Code Required Blower Door Test, Now What?

2012 was the first year the International Energy Conservation Code required residential construction to pass an air leakage rate test, better known as a blower door test.  My area of the country requires the test to be at or below 3 air changes per hour at the test pressure of 50 pascals (ACH50).  (Other areas, typically warmer climates require 5 ACH50.)  Most new construction in my market has no problem passing the test, but I have had a handful of houses fail, usually the failed tests are by a builder having their first blower door test or the project is a very small home.

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Construction Design-Chimney Chase

A modern masonry wood-burning fireplace with a factory built metal Class-A chimney system

Many homes that are (or were) heated with wood or fuel oil, or back in the day, coal, have (or had) masonry chimneys to move the exhaust from burning those fuels to the outside.  The chases used to hide these chimney systems are often areas of very high air leakage into and out of a home.  With the advent of modern heating equipment that more efficiently burns natural gas and propane, or a system that doesn’t use any burning fossil fuels inside the home to produce heat, such as electricity, the old masonry chimneys have all but gone by the wayside.  I have been in many homes, including my own, where the use of this type of chimney system has been discontinued.  Mine no longer extends through the roof; it terminates in the attic space.  Others have been completely removed.  Some new homes being built today still have chimney systems, the masonry chimney is rare, most install metal chimneys or use PVC vents. 

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Barndominium Part 4-Insulation and Air Control

This post first appeared on the Green Building Advisor website.  Residential Post-and-Frame Construction, Part 5: Insulation and Air-Sealing – GreenBuildingAdvisor

Cavity Insulation

I was brought on the barndominium construction team after many decisions were already in place.  The design was, for the most part, finished.  Many of the assemblies had been designed, such as the decision to use laminated posts six foot on center with the horizontal wall girts both inside and out.  The original plan for the insulation was to use up to seven inches of closed cell spray foam in the walls.  I was able to change the insulation strategy with a plan for a more “forgiving” assembly.  We chose to go with Rockwool’s 7.25-inch ComfortBatt, which has an insulation value of R-30. Continue reading “Barndominium Part 4-Insulation and Air Control”

Construction Design-Service Cavity

This post was first published at www.greenbuildingadvisor.com.

There are many methods used to make a home airtight, it all comes down to one simple rule, continuity.  Continuity is easily attained when there’s nothing that penetrates the air barrier.  No electrical boxes, plumbing drains and vents or ducts that need to extend from inside a building’s envelope to the outside.  Of course, there are times when different things need to extend from inside to outside, like the need for an outside water faucet.  But there are also many occasions when different systems end up outside that don’t need to be outside.  For example, forced air heating and cooling ducts that leave the conditioned space of the home simply because there was no space to keep them hidden inside the home.  Planning a service cavity can help keep most mechanicals inside the building envelope. Continue reading “Construction Design-Service Cavity”

Construction Design-Air Sealing Windows

I often hear during energy audits, complaints about windows.  Many homeowners feel the windows are cheaply made and replacement will result in substantial energy savings and an increase in comfort for the home.  Sometimes the windows are a major cause of comfort problems, more often, the window installation is the issue.  This blog post is about three different ways we air seal windows today.

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Building Science-Ice Dams

This year seems to be a good (or bad depending on how you look at it) year for ice dam problems in my area, the intensity of ice dams seems to change year to year.  I was recently on an ice dam diagnostic with an insulating contractor and a general contractor, the home was built in the early 1990’s and there is evidence there have been issues from the beginning.  We spent a couple hours testing this home, I’ll get into what we found in a bit.

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Building Science-Existing Construction Improvements

This three-part series first appeared on the Green Building Advisor website and has been condensed into one post.

An unconditioned and uninsulated crawlspace, an unsealed and uninsulated forced air heating system, and an uncovered dirt floor, which by the way has a sewage leak.  If this were your home and you wanted to make improvements, where would you start? Continue reading “Building Science-Existing Construction Improvements”

Construction Design-Insects and Rodents

When I purchased my old home, the 1952 Cape in late 2018, the basement area looked good.  Someone took the time to paint all the concrete walls and floor and cleaned everything up to look nice.  Shortly after we moved in, the cat caught a mouse and then the following summer, the basement became a bug gathering place.  Ants, spiders and other bugs apparently wintered in another area and returned to my house in the spring.

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Building Science-Three Way Buildings Leak Air

I have talked many times about blower door testing, air sealing and air leaks in this blog, on the Green Building Advisor’s website, and more recently, in the pages of Fine Homebuilding Magazine.  Most of what I’ve written deals with testing a home or techniques used in air sealing a home.  This time I’m going to discuss the mechanisms that cause air to leak, there are only three of them, but first a little science. Continue reading “Building Science-Three Way Buildings Leak Air”