How to Prioritize Energy Upgrades to an Existing Home-Part 2

I purchased my home in the fall of 2018.  I could have decided to build something new or forgo all the maintenance that comes with home ownership and rent.  Instead, I chose to purchase an older home that needed updating, both in appearance and performance.

The 24’ x 32’ home was built in 1952, a Cape Cod design with the normal problems of a Cape Cod, attic knee walls that were both inside and outside the air control layer.  There was some evidence of past water damage and a few old clips on the roof where a heat tape would have been placed, suggesting an ice dam issue.  The high efficiency natural gas forced air furnace appeared to be from the 1990’s, the same year as the electric water heater.  There was also a natural gas fireplace in the small living room.  There was a weird-shaped room on the main level (behind the sun and where the sliding patio door is located, 9’ wide by 24 feet long.  Two bedrooms, and a bathroom were located upstairs, a bathroom on the main level, and an area in the basement that had an egress window well that would support another bedroom. Continue reading “How to Prioritize Energy Upgrades to an Existing Home-Part 2”

The Effects of Poorly Installed (or Missing) Insulation

I was taught many years ago by an older fiberglass insulation contractor the importance of a quality insulation job.  His biggest piece of advice, FLUFF, DON’T STUFF!  Poorly installed insulation can have a big impact on the overall performance of a home.  In this blog, I’m going to show you mathematically how a small insulation deficiency can have a big effect in how a home performs.

This thermal image is a good example.  This was a brand-new home where I was performing a code required blower door test.  I ran around the home with my thermal imaging camera before starting the test and thought I might be able to use this image to show thermal bridging, which it does a good job at, but if you study the pic a little closer, we see several areas where the fiberglass insulation was poorly installed.  Compressing (not fluffing) the product creates areas of cooler temperatures in the insulation batts.  The dark area (at the ceiling on the right side of the photo) shows an area of missing insulation.  What effect does this poorly installed insulation have on the overall (effective) R-value?  We can show the results mathematically.

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Winnie Pretty Good House-Working with Huber’s Zip-R Sheathing

As builders and designers, we have so many ways we can improve the performance of a wall assembly.  Deeper wall cavities will allow for more insulation, double wall construction gains you the ability to move the air and/or vapor control to the middle of the wall leaving the inner framing cavity free for mechanical/electrical/plumbing (MEP) equipment.  Then there’s Building Science Corporation and Dr. Joe Lstiburek’s perfect wall, with the right ratio of continuous exterior insulation to interior cavity insulation that lessens the worries of vapor control.  Continuous exterior insulation can be designed in several ways, foam-based products, ridged mineral wool, wood fiber insulation, or nail base products.  And then there’s Huber’s Zip System R-sheathing, what we call on the jobsite, Zip-R.

Zip-R isn’t new, I first became aware of the product back in 2014.  What makes this product unique is that the continuous insulation layer is located between the exterior wall sheathing and framing.  This location simplifies the installation of CI and wall sheathing compared to the traditional location of the insulation, which is exterior of the wall sheathing.  And to add to the advantages of the product, in most applications, it is still a structural sheathing product when installed per Huber’s manufacturer’s instructions.  (Consult a structural engineer if there are any questions or concerns on a specific design or building location.)

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How to Design a Frost Protected Shallow Foundation System

My brother has an upcoming construction project on a property he owns that he’s asked for my help in both the design and construction of the structure.  There are portions of the project that are planned to be covered by Fine HomeBuilding Magazine plus I will be writing several blog posts for Green Building Advisor, Rockwool, and for my blog, Northern Built.  One of the first tasks is to plan the foundation system, in this case it will be a frost protected shallow foundation (FPSF).  The illustration below shows both the foundation and wall construction ideas.

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How to Attach Cladding When Using Continuous Insulation

This post originally appeared on the Green Building Advisor website.

One of the challenges with continuous insulation (CI) is how to attach cladding.  The cladding type and weight along with the type and thickness of the continuous insulation can affect the cladding attachment details.  This blog post will go over a few of the code requirements and discuss how the manufacturers of both the CI and cladding can help with prescriptive code compliance.

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Where to Locate the WRB when using Continuous Insulation-Inside or Out?

This post first appeared on the Green Building Advisor Website.

Right now, there’s a lot of interest in the residential construction market around continuous insulation (CI) strategies.  CI adds a layer of complexity to a build, and with it, questions.  How much insulation do I need?  How to fasten the insulation?  How to fasten the cladding?  How to integrate windows and doors?  What about vapor control?  And, this question, should the water resistive barrier (WRB) be at the sheathing layer or outboard the insulation?  The answer, it depends, but you have a lot of choices.

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What’s the Difference Between R-Value and U-Factor?

This post first appeared on the Andersen Windows and Door Website.

We were taught in junior high that hot air rises, the key to that phrase is air.  Heat itself moves from someplace warm to someplace cool.  A good example of this happens often in cold climates.  When standing in front of an old window on a cold night, you feel a chill.  This chill is the result of heat leaving your body and moving towards the colder surface of the window glass, heat moving from hot to cold.  To slow this movement of heat, we use insulation, by putting on another layer of clothes, we reduce or resist the movement of heat, we have added R-value.

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Ice Dams-Why They Form and How to Reduce their Risk

There is a lot of confusion as to why ice dams form on roofs in cold climates.  This is understandable, some years we experience heavy ice dams, other years have little to no issues.  Changes in weather from year to year can have a major impact on their formation.  I’ve seen new homes with ice dams that are completely related to winter freeze/thaw cycles.  That being said, most ice dam issues are directly caused by certain characteristics of the home, namely insulation levels and air tightness.

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Construction Design-Problems with Attic Trusses

This post first appeared on the Green Building Advisor Website

Attic truss, also known as a room-in-attic truss are a way to create a living space without the need to add a full second story to a home.  These factory-built roof systems simplify a roof buildout and are engineered to meet the structural requirements of your local codes and conditions.  I commonly see them used for bonus rooms over garages and integrated into slab-on-grade homes to add living space without needing to add to the height of the building.

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Vapor Control in Walls with Continuous Insulation-IRC Chapter 7 vs Chapter 11

This article first appeared in the January/February 2024 issue of the Journal of Light Construction.  www.jlconline.com

The International Residential Building Code is supposed to provide clarity into how builders construct homes.  In the IRC’s own words, The IRC was created to serve as a complete, comprehensive code regulating the construction of single-family houses, two-family houses (duplexes) and buildings consisting of three or more townhouse units.”  Usually, the codes do a decent job giving us options on how we should build homes with the occupant’s safety and health as our number one priority.  Codes also address energy efficiency and building durability.  Sometimes though, codes can be quite confusing.  How we handle vapor retarders when using continuous insulation is one of those areas.

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