Leaving a Slab Edge Un-insulated is like Leaving a Window Open

Climate zones

Improving the energy efficiency of a structure’s building envelop doesn’t end with the walls, windows and attic.  The foundation of a home whether a basement, crawl space or slab on grade needs to be insulated as well.

The International Energy Conservation Code (IECC) requires slab edge insulation and 36 states have adopted this IECC standard. The IECC code requires R-10 at the slab edge.  The requirement runs from the Canadian border (and Alaska) south, covering Climate Zones 4 and above. In California Title 24 mandates insulated edges for radiant slabs even if in Zones 1, 2, and 3, which predominate in the state.

As we have seen over the past 20 years, there has been a move to improve energy efficiency in all parts of the building envelop.  This is evidenced by the move to 2 x 6 wall construction to increase the amount of insulation in walls, the recommendation for increased amounts of attic insulation, and increased use of energy efficient windows.

Slabs have a stem wall that is similar to a foundation wall but without a basement. 60% of heat loss from the foundation occurs in the top eight inches of the un-insulated stem wall/slab edge; insulating these eight inches results in a tremendous amount of energy savings.

If your home is built on an un-insulated slab, the first 10 feet of floor from the slab edge will conduct cold because concrete has little R value (it takes 10 feet of concrete to achieve an R-10 insulation value).  Considering the overall footprint of an average home is approximately 25’ x 50’ there is a significant amount of first floor area that will remain chilled.  In fact, a properly insulated slab edge is estimated to save at least $200 a year in energy costs in addition to increasing comfort in the living space. 

There are products designed to insulate the slab edge for both current and new construction. For retrofit applications EnergyFlash® protects insulation that can be adhered to the slab edge and provides a durable decorative finish.  For new construction, EnergyEdge® forms and insulates the slab at the same time.  It provides the required R-10 value for slab on grade construction and is a great product for the contractor because once done pouring the slab no return trip to the job site is required to strip forms; also eliminated is the disposal of old wooden forms.  The builder benefits by eliminating the additional cost to insulate the slab after the pour.  

EnergyEdge saves time, money and energy. 

Moisture Management Remains Key Issue Across America

Lucas Hamilton

Lucas Hamilton

I recently spent some time in the St. Louis area and New York conducting workshops and trainings on moisture management. To my surprise the interest level in this topic remains sky high. The design community as well as contractors still have extreme need for knowledge around moisture management and design options to control this problem.

I guess because I have been dealing with the moisture and mold issues for so many years I feel that just about everyone knows how to protect against it but the truth is there are mold remediation cases from New York to California and it continues to plague the construction industry. But there are solutions to this age old problem – proper wall assembly design and product selection.

Following a training one my co-workers gave there were an hour’s worth of questions about moisture and mold issues. Questions such as:

• What is best assembly to prevent moisture?
• Higher insulation systems vs regular insulation systems?
• What about changes to the building codes regarding vapor retarders?

In a previous blog we did address the conditions that need to exist for mold to grow and we continue to develop solutions around this very critical issue.

We are in the solutions business and have crafted solutions and created balanced systems with products that can help to minimize moisture build up in wall assemblies and continue to conduct presentations and trainings to assist in the understanding of the best practices in resolving moisture issues in construction.

We will continue our efforts to help people build more robust assemblies and welcome the opportunity to respond to questions.

We need to fight the fight because this effects construction costs. The point is if you build it right to begin with you can solve half the problems that result in moisture and mold damage.

Lucas Hamilton is Manager, Building Science Applications at CertainTeed Corporation.

Creative Developers Dabble in Material Science

The Villages

The Villages

I recently visited The Villages and The Villages Construction Division in Florida.  They are lifestyle developers, creating a complete community including homes, recreation, and town centers.  The Villages is located north of Orlando and the community stretches 11 miles with 58 different neighborhoods or “villages”, dozens of golf courses and two old fashioned “downtown” areas.

One goal of their business model is to build quality homes as efficiently as possible. But they are in a climate with occasional summer showers. This can create a challenge as a developer can’t, typically, build wet houses and get away with it when moisture gets trapped. The Villages, however, meets the challenge and is succeeding against their unique environmental situation.

The homes are constructed with techniques ranging from stick-built wood frame to concrete masonry unit (CMU) to cast-in-place concrete. The CMU structures and cast-in-place structures have a cementitious finishing system on the exterior. People familiar with the chemistry of concrete know that new concrete is very alkaline.  On the scale of acid to base, basic materials are alkaline and they actually burn like acids do. The scale ranges from zero to 14.  At seven, a product is neutral and is safe.  If material registers too low it’s acidic and if it’s too high it’s too alkaline.  Either creates its own unique challenges.

If anyone has tried to paint fresh concrete they know what alkalinity does to coatings; it actually burns them up.  For The Villages to construct the quality product they do, they need to dry-in the structures as quickly as possible.  As a result, they have worked with paint and coatings manufacturers to develop special primers that can be put on green concrete or mortar without burning the paint and thereby preventing failure within the year.  To meet the needs of their unique climate and construction schedule, this developer has sought out manufacturers who can work with them.

In order to succeed, The Villages went to science to create a solution and based on my observation, they have an exceptional product. And they are on track to sell over 2,000 homes again this year. 

In this economic climate, that is extraordinary.

Lucas Hamilton

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications at CertainTeed Corporation. 








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

It’s About Systems Not Just Products at Greenbuild

Lucas Hamilton

Lucas Hamilton

I’ve noticed a trend in trade show booth design incorporating computers that show visitors products via websites. This technique cuts down on the amount of materials being shipped to and from show sites.  CertainTeed has tried that as well.

But as I watch and talk to people at trade shows, I’ve noticed that they want to see and more importantly, touch products.  So CertainTeed has decided to go in a different direction with our booth (921) at Greenbuild, November 11-13, in Phoenix, AZ.

In our booth, we are constructing wall and roof systems from our materials, and instead of just having a panel that shows insulation systems or a panel that shows roofing systems, we are building the walls and roof to show those materials from the inside out and the outside in. We want visitors to see how high performing, very green materials can be used to assemble sustainable systems. CertainTeed is unique because we manufacture everything in these constructions but the 2 x 4 framing.

We’ve always had sustainable materials in construction but we were not using them to their maximum potential because we viewed them as individual components.  It’s not about materials alone.  It’s about creating systems and assemblies that not only come from sustainable resources but that perform in a manner which both reduces the energy consumption of a building and extends its life-cycle.  As a manufacturer, we are conducting our research on performance and product interaction. We think about products in terms of systems and want to help design professionals and builders to put together products in a green or sustainable way?

That’s what I like about our booth at Greenbuild: we enable visitors to not only feel the difference between an insulated backed vinyl siding product compared to a fiber cement siding but then show how they perform within an assembly. 

 Another aspect of sustainable systems is the indoor environmental issues like acoustics, ventilation/air quality, and durability.  Depending upon where you live, you want to create systems with appropriate products to meet your maximum goals for R-value, moisture management, ventilation and other variables. Properly designed ceiling products are critical to controlling the acoustics and light reflectance which also contribute to indoor environmental quality, comfort, and visually pleasing aesthetics.

As I have mentioned in previous blogs, retrofitting existing structures to make them more energy efficient is a major challenge.  How do we go back and fix them and make them last longer and perform better?  Dennis Wilde from Gerding Edlen Development Company will share the success they are having with their Sustainable Solutions program at our CertainTeed-sponsored luncheon at Greenbuild. They are mastering the process.  The challenge with green and sustainable building is that everyone is afraid of the learning curve. Everybody wants to be on the leading edge but they don’t want to be on the bleeding edge.  Gerding Edlen has bled the blood and figured out how to do it. They have paid the price in pain and it is a great gift that they are willing to educate the rest of us. 

The room is filling up fast so if you want to attend the luncheon at Greenbuild, email Kristen Harter, Kristen.M.Harter@saint-gobain.com.

Remember: a building that lasts twice as long is twice as green. Stop by and see us at Greenbuild Booth 921!

Lucas Hamilton is Manager, Building Science Applications, for CertainTeed Corporation

Green at work—At Greenbuild

Copy of Michael low res picWow, thanks for your very insightful thoughts regarding the promotion of green these days.  It seems, as we suspected, that overdone Green promotion does in fact ruin it for those who are trying to be responsible in their portrayal of green and sustainable products.

We’re headed for what I believe may be the one trade show that matters to people this year—Greenbuild, being held in Phoenix in November.  I don’t know whether it’s the promise of a keynote speech from Al Gore, the Sheryl Crow concert or the beautiful weather, but if my fruitless hotel search is any indication, it’s going to be well-attended.

Greenbuild will be a perfect time to gauge “greenspeak” among building products manufacturers. Again, it’s not about talking green; it’s about how responsibly we do so.  As I mentioned in my post the other day, I’m hearing from the architect community that we need to start integrating green into our everyday actions…by example and through the promotion of our products.

You’ll find us at booth #921 with a very different approach than in recent years.  We used to have a big chart outlining all of the LEED Credits you can potentially earn using our products.  Last year, you seemed much more interested in seeing actual product.  So, this year, we’re bringing the walls to you.  We affectionately call it the “tunnel of love,” but what we’ve got is a design that shows complete wall and roofing systems, from inside out, addressing the major sustainable issues of moisture management, sound control, energy efficiency, and recycled content.  A bit of a departure for us, but we’re excited.  Our favorite blogger, Lucas Hamilton will also be there with his tremendous knowledge of building science.

We’re also very excited to be hosting a luncheon featuring our friend Dennis Wilde from Gerding Edlen Development who will be talking about taking existing buildings and doing a comprehensive retrofit to improve energy efficiency, water and waste management and human comfort.  This is amazing since it’s easier to shoot for these things when building a new building vs. accepting someone else’s mistakes as your starting point—cutting edge stuff from a company we’re proud to be partnering with.

There are limited slots available for this luncheon.  If you would like to attend, get back to me at this address to be included in a drawing for one of these coveted tickets.  Keep the feedback coming!

 Mike Loughery is Director, Corporate Marketing Communications at CertainTeed Corporation.

Greener than Green or Green Fatigue?

Hello, my name is Mike Loughery and I am Director, Corporate Marketing Communications for CertainTeed Corporation.

Copy of Michael low res picWe’ve seen tremendous promotion by all types of companies about how “green” they are. The “greenest this” and the “most environmentally friendly that.” It’s easy to get caught up in it all.  We see consumers jumping on the bandwagon and we all follow right along, hoping to tap into what we think is an insatiable appetite for green and sustainable products.

And here we are, several years later and what have we accomplished? At CertainTeed, we have reached inside our core selves and found that a lot of what gets credit for being “green” these days already existed as very aggressive cost-savings initiatives—efforts that existed long before the green discussion started.  Our position is simple:  we strive to be the industry leader in the development of sustainable building products and the environmentally friendly operation of our facilities.

However, promoting “green” means only promoting what you can back up.  We don’t buy into the “greener than green itself” mentality which dilutes the message and impact of the overall green movement.  Unfortunately, there is so much overhyped green speak out there that the hard-working efforts of those who really want to make a difference in the world of sustainability are being hindered.  Everywhere you look there’s so much green–who knows what to believe?  Now, the focus becomes whether it’s “green washing” or the efforts are truly legitimate.

I hear it from architects and even the media—this idea of “green fatigue.”  So much so, that serious questions are being raised as to the legitimacy or believability of manufacturers’ claims in their advertising and marketing materials. 

I believe the appetite for green is still there, but maybe it’s time to do a gut check.  We all know that Green is here to stay.  Now, the challenge for all of us is to responsibly represent ourselves to preserve the integrity of what the green movement is all about.  Does it mean going low-key while letting our actions speak for themselves?  Maybe. 

We have a responsibility to promote and also educate about the true sustainable advantages of our products—energy efficiency, indoor air quality, moisture and mold resistance, recyclability, recycled content and so on.  All the other stuff is cheap window dressing.

If you’re green, great, promote it—but do so responsibly.  Back up those words with proof.  Consumers want the truth.  I’d be interested in your thoughts.  Where is this green movement going?  How can we promote green legitimately without causing distrust in the marketplace?

Mold Awareness Month – Mold is like a Four Legged Stool

Lucas Hamilton

Lucas Hamilton

Since there is a “month” for just about everything else, why not "mold awareness?"  While some may think this is a non-issue, I assure you, it is not.  Last year the governors of several major states proclaimed September of 2008 to be Indoor Mold Awareness Month.  Other states have now joined the push to raise public awareness of this potential health issue.  For people who have been exposed to mold and have had an allergic reaction, because that is what it is in most cases, it can be a serious problem. Reactions such as a rash, itchy skin, difficulty breathing or headaches have been a result of inhaling mold spores. Over the past 20 years, mold has become very well understood in buildings because of litigation, which bolstered research and conversation regarding the cause, effect and damages that result from mold.

Mold needs four things to live:  a temperature of 41 to 104 degrees; sufficient moisture content; oxygen and food. Mold is like a four legged stool, if you knock one leg out the stool falls over. If mold does occur in buildings there are very well established guidelines for remediation. Mold does not consume building materials, it does not cause structural issues – fungus does – which occurs at a higher moisture content than mold.  Mold is more common and can be dried out, killed, and wiped away.  If you keep the area dry from that point on, you will not have further problems.  People develop issues with mold when it becomes active and releases spores into the air.  Those spores are inhaled and, like ragweed, can cause an allergic reaction.  The trick is to control the elements of the four-legged stool. But how do we control these elements?

Temperature is something we create. We know that mold’s sweet spot is 41 to 104 degrees and I guarantee that you can find that temperature range in just about any wall anywhere in any season. 

Oxygen – you’re not going to get rid of oxygen unless you build your building on the moon. 

Food – starch or sugar typically are the food sources for mold. You can try to build a building that is food free but I guarantee you food will show up. A perfect example of how a food free environment doesn’t last is your shower, which is generally ceramic, glazed tile, glass, chrome, vinyl – there are no starches or sugars in these materials – but mold will grow because food shows up in things like soap.   Starch is one of the binders for soap. That’s the problem with trying to develop buildings without food sources, because food will show up in the form of contamination through the use and occupancy of the building.

The accepted strategy among building designers and construction professionals is to control the moisture so that you do not have a17% wood moisture content in materials. This is the moisture content at which mold will appear.  

We’ve never really been able to completely keep moisture out of our building constructions. The trick is to build living, breathing, drying assemblies that keep moisture content levels low. You can live with bursts above the 17% as long as you get the water out before the mold begins to propagate. If mold does occur in your building, deal with it in a considerate and rational approach: Protect people from exposure to the airborne spores, clean it up, dry out the substrate, and prevent the surface from achieving elevated moisture contents in the future.

 Lucas Hamilton is Manager, Building Science Applications at CertainTeed Corporation.  

                                   Nolan Mug shot             

Nolan Day, Architectural Systems Manager at CertainTeed Corporation contributed to this blog.

Blogging from Building Science Summer Camp

Stan Gatland photo_1I am Stan Gatland, Manager, Building Science Technology at CertainTeed Corporation.  I am joining my colleague, Lucas Hamilton, in the Blogosphere.

Every year, I have the opportunity to attend training for Building Science professionals affectionately known as Summer Camp. Ok, we call it camp, but really, there are no tents or campfires songs, or even horseback riding.  Actually, it’s officially called the Thirteenth Annual Westford Symposium on Building Science, sponsored by Building Science Corporation.) Not only is it a great opportunity to learn about the latest and greatest  Building Science trends but for me, the most beneficial part of  ‘Camp’ is the informal meeting of the minds to share current challenges and generate new ideas, solutions and debate about best practices. The attendees include architects, engineers, physicists, designers, builders, material scientists, manufacturers and other building professionals.

 There has been significant growth in the attendance at “Camp” over the years due to increased focus on the building envelope, energy efficiency, moisture management and sustainability.

I was particularly interested in the information presented by Andreas Holm and Hartwig Kuenzel from the Fraunhofer Institute in Germany.  The interest in building science actually began with the introduction of insulation into buildings in Europe in the early 20th century and led to the establishment of the Institute for Building Physics at the Fraunhofer Institute. Historically, Europe and Canada are well ahead of the US with regard to Building Science.

 Among their topics was the discussion of how whole building performance changes with respect to moisture when adding thermal insulation. Adding insulation reduces the amount of heat that flows through an assembly. While this improves energy efficiency and thermal comfort, it also reduces the amount of energy available to dry assemblies and can cause colder surfaces to accumulate more moisture over time. The Institute is looking at ways to improve the moisture management performance of buildings that have become very energy efficient.

They also talked about indoor climate control and energy concepts for schools. Making buildings more air tight may require indoor humidity control through fresh air ventilation.

If you have participated in one of these, or have some thoughts on building science topics of interest, let me know.  I’m glad to be one of CertainTeed’s “Blog-gurus” and look forward to talking with you on occasion.