Designing and Building High Performance Homes, and Building "the Perfect Wall" using Stone Wool Insulation - A Video Series in 8 Parts

Posted by: Rate It Green Team

In this 8-part series hosted by Rockwool, Chris Laumer-Giddens of LG Squared, Inc. walks us through some of the high performance homes he’s built, the basics of well-built wall assemblies, and the top reasons he builds with stone wool.  Watch the videos one at a time, or watch them all through.  We also highlight the key concepts covered below, so you can preview the content addressed in each video.    

Video 1: Introduction: 

Kick off an 8 part videos series on designing and building with stone wool insulation with a history of LG Squared and Chris’ experience, and an overview of control laters, air tightness, and 7 reasons to design with stone wool.   

Growing Interest and experience in high performance homes since 2010, fueled by stimulus funds for new construction and major renovations.  As the economy got better, there was more interest in whole homes that used less energy and were also more comfortable, required lower maintenance, durable, and could look great as well.  
 

Video 2: Discovering High Performance Homes:

Video 2 kicks off with a case study of a beautiful historic renovation in the Atlanta, Georgia area, as well as a new construction show home and a high performance net-zero bungalow, also in Georgia.  Chris walks through the wall and roof assemblies of each home, and he describes some of the lessons learned along the way.  

Video 3: Understanding the 2nd Law of Thermodynamics and Hygrothermics 

Here, Chris reviews the 2nd law of thermodynamics…  high pressure to low pressure, hot to cold.  The principal explains why a lot of insulation started moving to the exterior - to keep occupants warm but also to protect the structure and materials of the home.  Additionally, hygrothermics explains drying potential, that water is also going to find its way to the lowest pressure.  It’s critical to understand hygrothermics to keep water out of our buildings.  

Video 4:  Designing the “Perfect Wall”:

What is the perfect wall?  The perfect wall assembly contains 4 Control layers:

• Water
• Air
• Vapor
• Heat

Chris and other students of building science prefer to keep the control layers outside of the structure, for continuity of the insulation, simplicity of installation, and moisture control, among other factors.  

Chris works mostly in Georgia, Florida, and North Carolina, but the principles hold anywhere in the world.  

Video 5: Continuity is King - Uninterrupted Control Layers and Absolute Airtightness:

The key to protecting the perfect wall is to continue the control layers up to the roof and down to the floor. Anywhere there is a potential break in that layer, you must address it and make sure that everything stays continuous.  

In addition to water management, airtightness is absolutely critical.  You want to keep the conditioned air inside, and you don’t want to let the bad/polluted air in either.  With air comes moisture.  Keeping air under control is essential for humidity management, which is particularly critical in the Southern 3A climate zone, where Chris does much of his work.  It’s impressive that homes built this way do not even need dehumidifiers due to proper air tightness and system sizing.  Moisture also carries heat, so keeping out moisture will help with heat loss and gain.  Tightness also keeps out “critters!” 

Benefits of airtight construction include:

• Keep conditioned air in
• Kee polluted air out
• Control humidity
• Control moisture
• Control heat loss and gain

Video 6:  7 Reasons to Design and Build with Stone Wool: 

In this video, Chris explains the top reasons he uses stone wool as an exterior insulation. 

• Fire resistance
• Drying potential
• Resistance to expansion and contraction
• UV Resistance
• Pest Control (“Critters don’t seem to care for it”) 
• Durability (Rocks have been around for ages; we know they hold up to all conditions)
• Ease of installation 

Video 7: Case studies - Tips, tricks, best practices, and lessons learned:

In this video, Chris describes some of the path to where he is today, in terms of some practices and lessons learned along the way. He starts with a Florida tiny home/cabin and explains how he designed the walls and experimented some with the floor to keep continuity. Chris’ efforts to attack every potential leak source certainly went above and beyond. 

Next up is a North Carolina Blue Ridge Mountain home where the owners pay an average of $50 a month for energy, with a maximum of $100 at times, for  3500 sf home.  Apparently, the occupants don’t need the gas fireplace they installed, as the home is just so well insulated.    

Chris also shares an off-grid Western North Carolina home where the owners wanted to be completed disconnected and independent.  This home used 6 inches of exterior insulation on the walls and 8 inches on the roof, the most Chris has used on a project.  He also mentions briefly a set of off-grid cottages in North Carolina that are very similar to this home.  

Chris continues with a project he’s currently working on, where the attention to detail and durability is truly impressive.  We note the effort to keep termites out with tightness, as opposed to needing to use chemicals in the future.  The idea of really testing materials and techniques with a practice mock up wall (on every project) is also noteworthy. 

Chris includes a high-performance home in Marietta, Georgia.  This home used a liquid applied membrane. Chris and his team were able to achieve a great air exchange rate between this material and testing penetrations to find and address any possible leaks pre penetrations, and then sealing those up tight as well.     

Video 8. Q & A:

The final video in the 8-part building with stone wool series provides an opportunity for Dan Edelman to present the Rockwool Elite Builder program, of which Chris Laumer-Giddens is a participating builder.  Dan reviews program benefits and introduces the idea of rebates, which will vary depending on the location and time (so its best to check back in with him regarding incentives).

The two address questions that came up during the full presentation, starting with a question about a termite barrier.  Chris also addresses his preferred cladding, which van vary depending on the particular project. He uses fiber cement, a composite, or a metal on all projects, though there are some options for treating wood. Key is low maintenance and avoiding the need for caulking (which can fail) or sealants.  They minimize these practices with rain screen systems that already allow for water and air movement.  Chris also shares tips and his experience working with windows and exterior insulation.  The idea of protecting every element of the structure from exposure  for the life of the building makes a return appearance during a conversation about continuity, as a key part of both high performance and durability.