When it Comes to Air Tightness in Buildings – Don’t Forget the Garage

 
 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Many of our houses have attached garages which are, for the most part, unconditioned space within our habitat.  It is the interface of these two spaces which so often fails in our attempts to conserve energy and have superior indoor air quality. 

For starters, you have to make sure that the garage is air sealed from the rest of the structure because of what you store in that space. You store things in your garage because you want them out of the weather but you don’t want them “indoors.” Very often negative pressure is generated in the home by exhaust fans and dryers. In your home’s attempt to reach a neutral pressure with the exterior, it will often pull air from the garage into the home.  Now all of the gaseous and particulate contamination which is associated with what you are storing and doing in your garage is coming into your home. Think about what is on the other side of these “interior” walls – typically they are the rooms where we spend the most of our waking hours; kitchen and family room. If the separation plane between these spaces is not made air-tight we might as well move into the garage.

One small detail which is best addressed during the time of construction is breaking the continuity of framing chases between the garage and the house typically found in the garage ceiling. As the second floor framing runs continuously across one of the garage interior walls, air-tight blocking needs to be installed between floor framing to close this avenue of air migration. This is obviously easier to achieve with dimensional floor framing or “TJI” (Trus Joist I) than it is with modern trusses. Also ensure that any doors leading from the garage to the living space are properly sealed and air tight. Get a new door sweep if the old one is worn out. One great indicator of an air leaky passage door is a dirt “shadow” in the carpet just inside the sweep. Carpet fibers make excellent air filters and atypical soiling patterns are great indicators of air flows.

Once you’ve decreased uncontrolled air flow between the home and the garage is there added value by adding an insulated exterior garage door?  Absolutely! Any way that you can tighten or insulate the envelop will improve the efficiency. When you are making any changes with regard to air tightness in the home don’t forget to include the garage in your decisions.

It’s Not Just Wallboard Anymore

 

Ashwin Himat

Ashwin Himat

Ashwin Himat is Director of Marketing – North America for CertainTeed Gypsum

New innovations in technology are redefining building products industry-wide. Manufacturers are improving products today based on solutions to environmental concerns and to address indoor environmental quality. Wallboard is no exception.

Historically, wallboard enabled residential and commercial construction to provide better fire protection and a flat, smooth surface that could be easily painted or wallpapered. Because of the recycled content of wallboard, it has always been considered a sustainable product but its function rather than its features were the primary selling point.

The drivers for innovation of wallboard products predominately came from the commercial build community. Earlier innovations in wallboard provided moisture resistance for areas of buildings with high moisture such as bathrooms and kitchens. With increased concerns and claims regarding mold in buildings, a technology was developed to provide mold and moisture resistance to wallboard.  Mold is a potentially serious health issue for people so the ability to include a mold resistant wallboard in a home or building susceptible to mold reduces the potential.

With the rapidly growing awareness of the importance of indoor air quality and its impact on health and productivity, recent technology innovations have led to the introduction of wallboards that clean the air.  By removing volatile organic compounds (VOC’s) such as formaldehyde and other aldehydes from the air and converting them into safe, inert compounds, these wallboards can improve indoor air quality for generations. 

In response to the growing marketplace demand for acoustic comfort, manufacturers have increased innovations in the area of noise-reducing gypsum board, specifically designed for wall systems requiring high STC ratings where acoustic management is needed.

The commercial build community is aware of these advancements in wallboard and they are including them in specifications especially in the educational and healthcare arena. But these wallboards adapt well to residential construction as well especially when designing custom homes that may include home theaters or music rooms.

Homeowners need to be educated about the options they have when either building a new home or expanding an existing one.  Decisions made about the walls and ceilings of a home should be carefully considered because ones overall comfort depends on it.

Wallboard is not a one size fits all product any longer so when it comes to improving comfort and indoor environmental quality remember to consider the best solutions for your walls and ceilings.

Quantifying the Value of Sustainability Going Forward

Lucas Hamilton

As we continue to improve energy performance, acoustics, comfort and aesthetics in our buildings, we are left with the challenge of quantifying the impact of these practices and how much they influence our quality of life.

This is a needed validation of sustainability – evaluating the effects that improving systems has on the occupants over a period of time.  While we are preaching the gospel to improve the performance of our buildings by including more natural light, better indoor air quality, improved acoustics and overall comfort are we quantifying how these changes improve employee or student performance in an improved environment?

For example, we have a need for connectivity. Older buildings were not built to provide ample natural light needed by people. Workers who sit in cubicles with no window tend to feel disconnected because they lack connectivity. Think about it when you enter a room, do you take a seat that enables you to look out a window?

Are we adequately documenting whether:

  • Students test scores improved because they could hear the teacher better?
  • Worker productivity increased because they had access to natural light?
  • Absenteeism decreased because of improved indoor air quality?

Some decision makers will argue that there are only two kinds of decisions: rational (based on facts) and irrational (not based on facts.) I would suggest they change these terms to fact-based and faith-based. In our private lives we make decisions based upon faith all the time and we are completely comfortable doing so. I think we need to develop more data to help less confident decision makers defend their faith- based decisions with some facts. If we are successful, eventually some of these decision makers will develop enough confidence to be truly innovative.

Are there other ‘quantifiables’ that we should consider to justify the decisions we are making now and in the future? I would like to hear your thoughts?

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Radon Mitigation Starts with Proper Home Foundations

Lucas Hamilton

The use of foundation drainage systems helps with water control, mold and moisture issues and Indoor Environmental Quality (IEQ) in a building. But, bear in mind that those same remedial efforts, if using the Form-A-Drain system, will also help with radon mitigation. In the same manner that these systems relieve head water pressure on the cold joint of the foundation / footer, they give migrating radon gas a path of least resistance away from the home.

Radon gas is a colorless, odorless, tasteless noble gas, occurring naturally as the decay product of uranium. Radon gas from natural sources can accumulate in buildings, especially in confined areas such as attics and basements.

Most regions of the U.S. encounter radon gas especially if they have basements or crawlspaces.  It is important to test for radon especially if the basement is part of the living area of the home.

Many homeowners are not aware they have a brewing radon problem until they put the house on the market.  It can, in some instances, be costly to install a radon mitigation system.

Leave in place Form-A-Drain systems pay for themselves not only in their benefits related to the forming of footings and moisture management but the added value of what they provide with regard to radon venting; making the use of Form-A- Drain product for all new construction projects the best ‘drainage’ solution for contractors, architects and builders.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Mold Awareness Month: The Five “D’s” to Controlling Mold

Lucas Hamilton

The U.S. Environmental Protection Agency (EPA) estimates that 50 percent of schools nationwide have issues linked to poor indoor air quality.  In many cases, this condition is linked to mold growth in buildings. Mold poses a serious health risk to individuals with respiratory health issues.

This has been a summer of record high temperatures and humidity across the country. This is a perfect storm for the propagation of mold.  As I discussed last year, mold is like a four legged stool.  Mold needs four things in order to grow:  food, water, oxygen and temperature between 41 and 104 degrees.  It is almost impossible to eliminate the potential for molds and mold spores to infiltrate an environment unless you control the elements that give mold it’s ‘legs.’

Controlling the moisture in and around a building is one of the best methods for maintaining a mold-free environment.  By following the five “D’s” you can protect against any opportunity for mold growth or infiltration:

De – Leak – Check for leaky roofs, walls, windows, foundations, facets and pipes regularly and repair them as soon as possible.

De – Bubble – Moisture trapped behind wallpaper paired with wallpaper glue is a perfect recipe for potential mold growth.

Dehumidify – Use dehumidifiers and air conditioners, especially in hot, humid climates to reduce moisture in the air.  Exhaust fans should be used in bathrooms and kitchens to remove moisture to the outside.

Dry – Clean and dry any damp furnishings within 24 to 48 hours to prevent mold growth.

De – Odor – Keep in mind, if you have had a leak, the first sign of mold may be musty or moldy odors. But do not sniff or touch mold.  If you suspect mold, contact a certified mold inspector.

Mold has a long history and a survival instinct that is almost unmatched in nature.  But let’s keep mold outside by making sure that moisture is managed in our buildings.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Indoor Air Quality Has A New Champion

Improving the indoor air quality of buildings is a large part of the sustainability movement and as we continue to address energy efficiency through air tightness in assemblies, the issue of indoor air quality will continue to be a focal point.

People spend about 90 percent of their time indoors so the quality of the air around them, where they live, work and play is very important.  Educational and health care environments draw even greater scrutiny due to the sensitivities of the young and those with potential respiratory issues.Volatile organic compounds (VOCs), formaldehyde and other aldehydes, are seen as common compromises to air quality.  VOCs are all around us, come from many sources, and often move freely in and out of building components. People, themselves, carry VOCs into buildings through the wearing of permanent-press clothing and exposure to secondhand smoke.

Fortunately, there is a first-of-its-kind wallboard, called AirRenew™.  AirRenew is designed to clean the air and remove a particular family of VOCs by drawing them into the board, trapping them, and utilizing a patented technology to break down these VOCs into inert compounds. Those inert compounds will stay in the gypsum board for the service life of the board.  These inert compounds created inside the core are not harmful and the original VOCs will never be released back into the air. 

This revolutionary gypsum board, which will be available soon, will have a positive impact on public buildings, especially when qualifying for Leadership in Energy and Environmental Design (LEED ™) or other green rating program certifications.  Indoor Air Quality (IAQ) strategies incorporating AirRenew meet the intent of the sustainability Triple Bottom Line of economic prosperity, social responsibility and environmental stewardship.

AirRenew has undergone a battery of independent testing. Preliminary tests show that AirRenew maintains its performance when painted with a permeable paint. Finishing that results in an impermeable surface, such as vinyl wallcoverings, would reduce the porosity of the board surface and are not recommended. Permeable paints currently serve over 70 percent of the interior wall coatings market. Since most sustainable and LEED models are moving away from solvent based coatings, this is not perceived as a limitation.

LEED for Schools Indoor Environmental Quality (IEQ) Credit 3.2 sets a maximum concentration of 27 parts per billion for formaldehyde, however many studies have shown that this is often exceeded. The mold resistance performance of AirRenew also contributes to LEED for Schools IEQ Credit 10 for mold prevention. The GREENGUARD® Environmental Institute has many resources documenting the issues of indoor air quality and the need for reducing VOCs especially in schools.

It has been exciting to work on a product that provides a real solution to an issue that has long needed a champion product. 

Multi-Comfort House Competition – Global Event of a Lifetime

Philadelphia University students (left to right) David Cremer, Daniel Hitchko and Christopher Anderson

I had the wonderful experience of accompanying the winning architecture students on a trip to Innsbruck, Austria to compete in the Isover/CertainTeed Multi-Comfort House competition sponsored by Saint-Gobain as the U.S sponsor and partner with Philadelphia University.

This competition started in 2005 with nine countries participating. There were now 18 countries represented, 32 universities, 46 projects submitted and 150 participants.  In some cases, submitting universities brought their top three projects. In many universities, the Multi-Comfort House competition is incorporated into the third and fourth year architectural program.

I must admit that since this was my first experience with the International Isover/CertainTeed Multi-Comfort House finals, I was concerned that it would be more like a social event than a serious competition.  I was pleasantly surprised to find I was wrong. The level of professionalism on the part of the competition organization and the high quality of the projects presented by the students was eye-opening. 

The subject of this year’s competition was the renovation of a five-story warehouse in the Parisian quarter of Pantin. Industrial building renovation to Multi-Comfort House standard was a tough challenge, but participants had the freedom to propose any function for the building. The projects ranged from a hotel, a library, a textile factory, a museum, a shopping mall, a student residence, a vocational training center, a meeting place for young people, to name a few. All were viable and of the highest quality in terms of execution, attention to detail and compliance with Passive House standards.

It was fascinating to see the range of design from both a technical as well as a romantic/creative aspect.  The work that was presented – the concepts and elaborate ideas – was surprising.  The level of knowledge and creative solutions with regard to air-tightness in buildings, increased insulation, moisture management and zero-energy applications employed in the designs were encouraging since these are the architects, designers and engineers of tomorrow.

From the students’ perspective, what an extraordinary experience to meet with global counterparts and exchange ideas, share successes and develop professional contacts.  Two of the American students had never been to Europe; this was life changing for them.

An added benefit for the students was the opportunity to meet and hear from Professor Wolfgang Feist, the founder of the Passive House movement.  He even incorporated comments about the designs that they presented and the techniques employed by the students.

The winning designs came from Austria, Finland, Serbian and Germany, but all of participants were fantastic.  The time they have invested in broadening their knowledge and practice of sustainable design principles, will certainly pay off in their professional life.

I am looking forward to supporting next year’s competition. The finals will be held in Prague and my hope is that we can begin to reach out to other American colleges and universities to participate in this program.

The Durability Challenge of Energy Retrofits

Stan Gatland

Stan Gatland

As a member of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),  I participate in technical committees that deal with building performance from a heat, air, and moisture perspective. One committee explores best practices for building envelope design. The committee focuses on how to manage heat, air, and moisture flow through assemblies. 

At a recent forum, members discussed concern that in the rush to create air-tight building envelopes with high levels of energy efficiency, the long-term impact on durability due to these changes may be overlooked.  Energy efficient, air-tight buildings have a greater potential to accumulate moisture and have less energy to dry out.

The Department of Energy is poised to support the energy efficiency retrofit of existing homes by improving air tightness and adding thermal insulation.  This time, hopefully, the history of the 1980s and 1990s does will not repeat itself regarding the durability issues related to energy efficiency retrofits.  Moisture related damage typically takes seven to 10 years after the retrofit of an existing home or construction of a new energy efficient home if measures are not taken to address moisture.

DOE recognizes the need to control interior humidity levels, as well as address combustion safety.  If adjustments are not made to control humidity levels and circulate fresh air it could cause other problems like excess moisture which could result in mold.

Another concern is combustion safety. By making an assembly more air-tight, you have less air available for combustion events. For example, hot water heaters and furnaces that once relied on a building’s air leakage to supply enough air to the combustion process may backdraft if enough air is not available in a well sealed home.   Direct ventilation may now be required to compensate for the retrofit.   

DOE is recommending that energy retrofit contractors address moisture management issues and combustion safety by following guidelines outlined in ASHRAE Standard 62.2 as a way to insure proper indoor air quality for residential buildings and increase the durability of assemblies.

Americans have traditionally had access to inexpensive energy but that is changing. We do need to address retrofitting older buildings, but it is crucial to not create other problems while doing so.

Stan Gatland is Manager, Building Science Technologies for CertainTeed Corporation

Embracing the Passive House

Stan Gatland

Stan Gatland

If there is any reliable source to confirm that the building community in the United States is beginning to embrace the passive house concept, it was the 4th Annual North American Passive House Conference held in October at the University of Illinois at Urbana-Champaign.  In 2008, there were only 15 certified passive house consultants in the United States but by the end of this year there will be over 200.  More than 300 architects and building professionals attended the conference this year.

 The passive house concept has been incorporated into building design practice for over 10 years throughout the world.  While many countries, including the U.S, have increased energy efficiency requirements for building through regulation, a relatively small percentage of industry partners have embraced the passive house concept on a large scale. 

The primary goal of passive house technology is to reduce your heating and cooling load so that very little energy is needed to maintain comfort.  It is critical that we control energy consumption and identify ways to improve our structures to improve their efficiency. It is understood that it will take time but programs like passive house build the awareness necessary to drive lasting change in energy conservation.

The ways to achieve passive house energy levels include increasing insulation in the walls and roof, providing pre-heated and pre-cooled air by coupling it with the ground through ducts buried into the earth (more practical on new construction), orientation of the building for maximum use of sunlight along with passive shading techniques, and installing high performance windows. But with the heightened focus on air tightness in passive house construction, more attention needs to be paid to indoor air quality and ventilation.

The other critical need to achieve any of these goals is the education of building occupants.  People need to maintain the systems in order to attain the maximum benefit.

Saint-Gobain, the parent company of CertainTeed, collaborated with the Passive House Institute in Germany and developed an educational marketing program called the ISOVER Multi-Comfort House.  

At the conference, I introduced CertainTeed’s Multi-Comfort House Educational Program which is a program CertainTeed will launch in 2010 to help train architects, building professionals and design students in passive house technologies.  The key components of the CertainTeed program are comfort (thermal, indoor air quality, acoustical and visual), safety and environmental protection benefits with design recommendations for all climate zones.

Understanding how products work together in the building envelope, especially in different climate zones, is critical to achieving passive house efficiencies.  Some valuable resources regarding passive house and net-zero building include the US Passive House Institute, the US Department of Energy – Net-Zero Building Technologies Program, the National Renewable Energy Laboratory, and the US Department of Energy Building America Program.

Stan Gatland is Manager, Building Science Technologies for CertainTeed Corporation.