Saint-Gobain’s Expert “Throw Down” at the AIA 2012 Convention and Design Expo

 
 
The excitement for this year’s American Institute of Architects (AIA) Convention and Design Expo is growing for Saint-Gobain and its family of businesses! We will be heading down to the nation’s capital from May 17 – 19 to help architects and designers solve problems they are having on specific projects and introduce them to the expertise within Saint-Gobain.

You might ask yourself—who is Saint-Gobain and what do they have to do with CertainTeed?  Well, Saint-Gobain is CertainTeed’s parent company and also the largest building materials company in the world.

You already know Saint-Gobain, it may not be that obvious though—our roots start in France where 350 years ago, we made the glass that adorns the Hall of Mirrors in Versalles.  Today, we make beer bottles for Budweiser, manufactured the new roof on the Dallas Cowboys stadium and through CertainTeed, manufactured the ceiling tiles in the Denver airport and made the roof that adorns Henry Ford’s home.  This is a mere, and I mean mere glimpse into this massive company, but, also a glimpse into the possibilities.

That’s why Saint-Gobain is bringing all of its businesses to the AIA show this week, and not just to show off products.  Saint-Gobain features the largest and smartest collection of building scientists and technical experts in North America from its trusted North American companies:  CertainTeed, ADFORS, Grenite, Norton, SAGE, Saint-Gobain Glass, Saint-Gobain Solar, Saint-Gobain Performance Plastics and SolarGard to help architects “solve the unsolvable problem.” We urge design professionals to bring your unsolvable problems to our booth and try to stump out experts!

This year, we’re talking moisture, indoor environmental quality, aesthetics, thermal efficiency and solar and our experts are ready to talk.  If you can’t make the show, check us out virtually Trade Show page that will share show updates through Twitter so that non-attendees can feel part of the action.  Through this page you can also ask questions or present unsolvable problems that our experts can tackle. If you submit an unsolvable problem you will be entered into a prize drawing.

During AIA 2012, we will be blogging here about show events and observations from guest bloggers.  Should be fun and entertaining!

Please join the conversation at AIA from your desk by bookmarking the Trade Show page. We want to help you feel part of the AIA Convention and to help solve your design challenges.

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.

Rainscreen Technology Featured at 2011 Solar Decathlon

 
 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

The 2011 Solar Decathlon held in Washington, DC in October featured homes designed and constructed by architecture and engineering students from universities worldwide that employ sustainable building solutions and powered by solar energy.

To my surprise, several of the designs, including Team Massachusetts, whom we partnered with, chose to include rainscreen technology in their designs. (Pictured is the fiber cement siding that was cut to accommodate the screen system designed by Team Massachusetts.

Rainscreens are a system which assumes that water will get beyond the outer surface to underlying layers and be managed and evacuated from the building.

It is not a barrier system – it is a water management system and they are great!

However, the market share in terms of the number of applications in the U.S. of rainscreen technology, the last time I checked, was approximately 10 percent. It is not a large part of the market but we are very familiar with versions of the rainscreen in our every day lives.  The brick cavity wall – the space behind the brick that drains the water out is a version of the rainscreen. This is the technique the students utilized with the siding.

Another example is the open rainscreen where panels are suspended off the building with clear passage around the panel.  There are no caulk joints, there’s nothing tight, you can see the underlying layers around the panels.

Rainscreen technology ranges from a drained assembly – to a drain and vented assembly – to a pressure equalized rainscreen which uses compartmentalization to prevent excessive positive or negative pressures from developing due to building orientation and exposure to wind and other elements.

This is an extremely durable system because the outer surface of the building repels the majority of the incident rain, deals with the majority of the solar radiation issues like ultra violet light and weathering.  It protects the underlying waterproofing and working layers of the building and enables them to hold up longer.

Rainscreens are great systems which are easier for a building owner because they are much easier to maintain. Perhaps the increased use of these systems in competitions like the Solar Decathlon will take hold as we continue to adopt new technologies for building assemblies.

Tools for Flashing Rough Openings – Not Windows and Doors

 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

I am struggling with an issue that keeps coming up with regard to the practice of flashing in building construction.  This is one of the most critical issues for ensuring that moisture will not permeate the building envelope. Earlier this year I wrote about the need to return to the construction techniques that our fathers and grandfathers adopted, especially, with regard to flashing

When I am conducting trainings and webinars on moisture management, which I do on a monthly basis, I am continually asked about flashing windows and doors.  I need to set the record straight – we do not flash windows and we do not flash doors –  we flash rough opens.  This is an important distinction.

Windows and doors are stuck onto a building so how can they be flashed?  They are accessories. The flashing is part of the rough opening in the wall assembly in addition to whatever features the window itself may have.

There are significant documents which clarify window installation practices such as ASTM E2112 which shows how to execute proper installation along with the proper flashing.  One of my favorite resources regarding flashing techniques in general is through SMACNA (Sheet Metal and Air Conditioning Contractors’ National Association). Their manuals give clear step by step instructions for folding materials to make various flashing shapes with minimal cutting.

Do not depend on glues and adhesives to prevent water intrusion.  Chances are they will not be permanently maintained by a building owner.

Stick to solid pieces of material that are installed in a shingle-like manner to continuously shed the water to the exterior and allow gravity an surface tension to drain the water from the building.

Excessive Wet Weather Can Lead to Mold

Lucas Hamilton

The historic rain that the United States has endured in 2011 has increased moisture levels in places where moisture has never been a problem. I have heard from many people around the country who have never had water in their homes but have recently sustained water damage and are now concerned about potential mold.

As I have mentioned in a previous blog, mold needs four things to grow:  moisture (liquid water), food (typically starch or sugar), temperature between 41° and 104° and oxygen.  When water is trapped behind walls or paneling, the other elements will most likely be present and the potential for mold growth will exist. Try to clean and dry areas subjected to water within 48 hours to help prevent mold growth. After cleaning and drying, continue to be sensitive to musty odors in the affected area.

Check the exterior of homes and building regularly for accumulating ground water.  Many parts of the country have far exceeded saturation and mold can begin for form outside and find its way inside. If water is accumulating against your foundation, take measures to drain the water away from your building. Keeping things dry is the key to preventing mold growth.

There are many products available today to help protect the home or building from moisture infiltration and mold growth.  There are coating products that can be applied to dry materials to mitigate any mold growth potentials for that surface in the future. If materials are wet and can’t be cleaned or completely dried, remove them from the building and replace them with new materials which may be more mold resistant. Fiber glass doesn’t have the food needed for mold growth but often when insulation gets wet, the water which intruded into the cavity was dirty and brought food along with it. If you have wet insulation, replace it with new fiber glass.  If replacing drywall, consider selecting a board that that contains mold and moisture inhibitors.

Many people have sensitivities to mold and it can be a health concern.  Make sure that you take extra care to check for mold especially if this is the first time you are dealing with water inside your home or building. Use a mixture of common sense and caution- if it smells or looks bad assume that it is bad and take appropriate measures.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Traditional Flashing Techniques Still Rule

Tom Silva from This Old House at CertainTeed's IBS booth

At the International Builders’ Show in Orlando, January 12 – 15, Tom Silva, general contractor for This Old House answered questions in the CertainTeed booth. One of the recurring issues that Tom discussed was flashing and the importance of proper flashing as a water barrier.  He really believes that barriers need to be constructed and maintained. 

At one point, he was talking about Fiber Cement siding and was asked what he does with the butt joints.  He said that you have to flash with physical materials and use traditional flashing techniques at all times.  He said that he flashes behind the butt joints and back caulks the boards to the flashing to prevent water from running laterally at the butt joints.

He obvious believes in traditional methods and good solid construction practices and flashing is one that is critical.  It occurs to me that we are at a low point in our cyclical knowledge process with regard to flashing. We are seeing more moisture issues because of incorrect flashing that has enabled water to penetrate. Often, we depend on newer materials to get the job done rather than using the time tested practices.  It’s funny because at one point during our discussions with Tom I mentioned SMACNA (Sheet Metal and Air Conditioning Contractors’ Association) and you could immediately tell who the seasoned builders were in the audience.  The SMACNA Manual is the sheet metal workers bible. It illustrates how to fold any piece of metal into any shape so that you don’t have to cut it. It is like origami for sheet metal. It seams that buildings constructed using the types of flashing shown in that manual have fewer moisture issues than their newer neighbors.

There are many traditional building practices that we forget and flashing is one of them. When all the failures to keep moisture out of the wall assembly point back to that simple interface between two dissimilar systems and how they should have been closed with a piece of good flashing, it becomes obvious that the basics will still work. You can’t ignore them! For example, why continuous nailing fins on a window is considered self flashing is beyond me.  You haven’t flashed anything. You have just sealed the eventual window leak into the wall.  You have not flashed and redirected to the outside. After all, it’s not the window that needs to be flashed, it’s the rough opening!

 

Lucas Hamilton

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

Not all Building Wraps are Created Equal – Technology and Common Sense Must Go Hand-in-Hand

Building wraps are now required behind all cladding by the International Residential Code. If you are building over a wood frame you must use a secondary water resistive barrier (WRB). Recent research has shown that as much as 10 percent of the wind driven rain is getting past the cladding onto the back-up layer. Intruding water must be redirected toward the exterior and not allowed to accumulate within the wall assemblies. This is the function of the water resistive barrier.

When selecting a building wrap you need to consider:

  • Install-ability – Is it tough enough to withstand exposure to the elements over a period of time?  Building wraps need to hold up to winds, not rip over staples and stay in place once installed.
  • Balanced set of physical properties – Select a material that is somewhat vapor open but not too vapor open.  There is a relatively healthy balance for a variety of cladding assemblies based on what the appropriate permeance is at that layer.  Much of the computer modeling that I have done over the years indicates a good general number for the permeance is between 10 – 20 U.S. perms for most U.S. climates.
  • Always install in accordance with the manufacturer’s recommendations –  This becomes your principle means of defense for moisture.  Moisture intrusion must stop at this line.

Building wrap needs to be installed in a shingle-like manner, so that it sheds water to the outside. It should also be installed in coordination with flashings and other accessories to ensure that any moisture that does intrude the assembly gets stopped at this layer.  It must then be redirected to the exterior and not become entrapped within the wall somewhere else.

Common sense is something that our fathers and grandfathers did far better than we do today.  Today the tendency is to rely on the silver bullet of technology to help pull us out of the fire.  The fact is, if you take these materials and install them with a great deal of common sense and construction knowledge, as older tradesmen did, then they work really well. In the best circumstances, the marriage of good technology and practical knowledge coincide and we construct durable and sustainable buildings. The correct application of a proper water resistive barrier is an example of such an installation. It’s not rocket science, it’s good building science.

 
 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Tolerance for Moisture Intrusion is a Challenge in Vancouver

Lucas Hamilton

Earlier this week I traveled to Vancouver, British Columbia, Canada to present the workshop on Mold and Moisture Control in buildings at the final [Be Certain] event.  It has been fascinating to present these workshops in different Northern climates and creating simulations to address the specific challenges faced in these areas of North America.

Previously, I blogged about polyethylene in Calgary, Alberta, Canada and the challenges faced in controlling moisture because of the use of exterior insulation. In preparation for my Vancouver workshop, I re-ran the modeling for Vancouver and the results were very interesting.

Polyamide films, like MemBrain™ because it is a breathable vapor retarder can provide additional tolerance for moisture intrusion in many climates, but in extreme climates like Vancouver there is almost no way to survive water intrusion.

In such climates, the best course is to build into the design redundant drainage planes and flash, flash, flash. Expect water to pass your principle line of defense and stop it with a secondary line of defense which will evacuate the intruding moisture to the exterior environment. This would be like a window rough opening being completely wrapped prior to window installation and this rough opening flashing draining water out and onto the face of a water resistive barrier (WRB) which leads to an egress at the base of the wall system.

While there is so much we know about moisture management, there is always more to learn and our thinking must be comprehensive. If we don’t learn from the past, our attempts to build air-tight and moisture-tight buildings will leave us looking more like Wile E. Coyote grasping for the next solution. I am not comfortable with that. Thoughts?

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Is Polyethylene Creating Potential for Mold?

Lucas Hamilton

Last week, I was in Calgary, Alberta, Canada for one of CertainTeed’s Be Certain events conducting training sessions on designing for Mold and Moisture control in buildings.  In preparation for the sessions, I ran computer simulations on typical construction models in Calgary.  This gave me a better awareness of how they build as well as scientific understanding of construction practices in the province.

In extremely cold and dry climates like Calgary, which is similar to Colorado, use of exterior insulations is very common.  This practice emphasizes the use of insulation on the outside of the building.  This cuts down the thermal connectivity of the building frame to make the building more energy efficient.

The 2009 International Energy Conservation Code (IECC) mandates the use of exterior insulation in cold climates. However, when you do this with traditional materials such as rigid foam plastics, you may reduce the potential to dry a building to the outside.  If a wall gets wet normally, dry air on the outside can act as a reservoir to dry the building. When insulations like extruded polystyrenes are used on the outside of the building, while being extremely energy efficient, they may reduce this drying potential.

Some new computer modeling tools have the ability to create window leaks and other scenarios that could occur from construction defects that would place water into the wall.  In the Calgary scenarios I ran, if a window leaks and the water is not drained to the exterior surface of the water resistive barrier, it becomes trapped between two non-breathing layers – the exterior insulation and the interior traditional vapor retarder polyethylene (which they still use in Alberta.)  The wall can not dry and this creates the risk of growing mold. 

Building scientists and manufacturers have been preaching eliminating polyethylene from our buildings here in the U.S. for quite awhile, and promoting the use of smart vapor retarders as a solution to the problem.

As construction practices change to keep more energy in the building, some of the measures taken may unfortunately alter the traditional moisture balance of the assemblies and actually reduce our tolerance of intruding moisture. We must be very mindful of this as we continue to tighten our buildings while striving for improved indoor environmental quality.

We conclude our Be Certain events in Toronto and Vancouver later this month.  Stay tuned for how mold and moisture affect the building envelope in Ontario and British Columbia.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation