Kirk Moore, CEO of Vermont based bpEnnovations, recently sat down with building materials sales & marketing consultants D R Sales & Marketing to discuss the many issues surrounding proper attic ventilation and their new Aerix Attic Ventilation System.

D R Sales & Marketing: Kirk, proper ventilation and protection of insulation in roof structures is one of several important components that affect a building’s performance in regards to energy conservation and air quality. What are the key factors that make this true?

Kirk Moore:  First, I think it is important to point out that roof ventilation and protection of the insulation is often overlooked by builders today. The concept of roof ventilation is not new – in fact it has been required by building codes for many years.  Today we are building structures much tighter than ever before to meet new standards for energy efficiency. This has changed the dynamics of the building envelope – most notably the ventilation and insulation component. Before this change, moisture control was not a big issue because, for the most part, our buildings leaked so much air, the moisture had plenty of ways to get out. Because the building envelopes are so much tighter than two decades ago – it is now more critical to correctly ventilate attics to prevent moisture build-up which can cause structural damage and mold.

Integral to the ventilation of the attic space is the protection of the insulation against wind washing caused by air currents introduced to the attic space through the soffit vents. The air entering the soffit needs to be directed to a vent channel installed at the underside of the roof deck and isolated from the insulation. This is accomplished be installing a wind block at the outside face of the exterior wall which also creates a dam that prevents blown –in insulation from filling the soffit and blocking off the soffit vents. This is the most often overlooked detail in attic ventilation.  Air movement, or wind washing, through insulation reduces its thermal resistance and thus its energy efficiency. Wind washing will also move blown-in fiber insulation away from the attic perimeter leaving substantial areas of the attic un-insulated – resulting in significant additional energy consumption.

DRSM: Over the past decade, the “green” movement has been gaining momentum across the globe. How does the design and construction of building envelopes play into “being green”?

KM: As an architect, I believe that improving the building envelope is the biggest contributor to sustainability – or being green. Reducing the demand for heating and cooling, which is the lion share of energy consumption, by building high performing envelopes -simply makes sense.

DRSM: In part, the recent emphasis on building envelope construction has also been driven by new energy codes and changes in building codes that are setting new requirements for insulation methods, ventilation, and moisture control. What are some examples of these code changes and how exactly does the Aerix Attic Ventilation System fit in with these changing requirements?

KM: Several states in the northeast have already adopted energy codes that require a wind block in every framing bay at the roof eave, as well as ventilation. We expect that most of the other states will soon follow. Aerix has been engineered to meet the current code requirements as well as some other changes we anticipate will be coming. The Aerix eave baffle vent provides an integral wind block and vent channel which isolates the soffit delivered air movement from the insulation at the eave – protecting it from the effects of wind washing.  The Aerix system can be used with all types of insulation – spray foam, batt, and blown-in fiber.

DRSM: Are there currently any manufactured products on the market that creates both the ventilation channel to provide air flow, and a baffle required to hold back the insulation from the soffit cavity? How does the Aerix Attic Ventilation System differ from these products?

KM: There are several products on the market – none of which do a very good job in terms of performance. The cardboard versions, although the cheapest in price, are difficult to install, do not provide for adequate insulation at the outside wall face where it is most needed and are prone to moisture and mold. The one styrene version that has a wind block and vent channel is brittle, not adaptable to roof variations, and very difficult to install. The one other pvc plastic version installs a bit easier than the others in new construction, although it too is a thin material that can be brittle and often will not hold a staple. Like all the others it also must be cut to fit around ceiling joist and is limited to steep pitched roofs. None of these products can be used with dense pack insulation. All of them require fastening at the eave – which in most cases is difficult if not impossible to reach – especially in retrofit applications. Individually, these other products have limited applications where they work at all.

Aerix was developed to address all of the shortcomings of these products.  It has been engineered to adapt to most roof variables and configurations, such as roof pitch, heal height, conventional roof framing with ceiling joist, and trussed framed roofs. It has also been developed with the installer in mind. The Aerix eave baffle vent does not require any fastening at the eave top plate – due to its friction fit design. Only two staples are required at the end of the panel that is most accessible. The Aerix system includes a continuation panel that interlocks with the preceding panel and is also fastened to the roof deck with just two staples. The continuation panel has two applications;  for low pitched attic roofs where additional clearance is needed between the top of the insulation and the roof deck to insure that blown-in insulation does not fill in the vent channel and; for cathedral ceiling applications. Aerix is the only product on the market that can withstand the pressure of dense packing cellulose in cathedral ceilings. It can also be used with all spray foams and batt insulation.

Aerix is a vacuum formed product manufactured from 15 gauge recycled PVC plastic – twice the thickness of the competitor with a similar product. The panel’s formed structure makes it rigid and easy to handle during the installation. It has been tested for dense pack cellulose up to 4.5 lbs density per cubic foot. The Aerix panel also provides over 30% more ventilation area than the other products on the market.

DRSM: The building science community has mixed opinions on the ventilation of Cathedral roof ceilings assemblies. Where do you and bpEnnovations stand on the issue?

KM: Based on my experience in the field and reading many studies and reports on this topic, it is my professional opinion that a vented roof deck is the most sound design approach.  A non-vented roof assembly requires a nearly perfect installation – which is not a realistic expectation in the construction industry. A vented roof assembly is simply safer by being more forgiving – if any moisture does get in – it can get out through the vent channel. If there is any breach in the non-vented assembly it usually ends up trapped at the underside of the roof deck – causing rapid deterioration of the deck and structure and often mold. These failures  can be costly – so why take the risk? Frankly, I believe that the non-vented roof approach came about because there was not an easy, cost effective way to build a vented cathedral ceiling. Aerix has solved that problem.

DRSM: Do you feel that there is adequate awareness on the greater issues surrounding roof ventilation, or is more education needed? If so, who requires that education (builders, architects, insulation contractors) and where can they gain it?

KM: No, I do not feel that there is adequate awareness on this issue. And yes, more education is definitely needed. For many people roof ventilation and moisture control is not a very tangible issue and therefore has not been on most people’s radar. It is equally, if not more, important than the type of insulation, windows, siding, decking, or interior finishes one chooses. I continue to be astounded by the lack of knowledge that builders and architects have on this very important component of the building envelope. The internet is full of information on this topic, and many building science professionals have written about it.

DRSM: How important is it for companies like yours to gain the endorsement from insulation manufacturers of your attic ventilation system? Are you in the process of gaining such endorsements and affiliations?

KM: We believe it is very important to us as well as the manufacturers. Aerix is a superior system that contributes to the performance of the insulation. Unlike all the other products on the market, Aerix is adaptable to most of the roof variations out there and is easily installed in new construction as well as retrofit applications. It is also the only product that can be used with every type of insulation. I think that the insulation manufacturers will appreciate these attributes and will find it to be in their interest to support the product that best insures the performance of their products. That product is Aerix. We have already started the dialogue with the major manufacturers and look forward to seeing what opportunities may develop.

DRSM: What is the Department Of Energy’s current take on roof and attic ventilation?

KM: The Energy Star program, which is administered by the Department of Energy, requires the installation of wind blocks in the attic and proper attic ventilation. The D.O.E. has published several technical papers on attic construction covering proper insulation and ventilation.

DRSM: How big a role does your National distributor Parksite play in educating dealers, builders, architects and contractors on not only the Aerix Attic Ventilation System, but on the overall issues surrounding roof and attic ventilation?

KM: The Parksite building specialists play a very large role in downstream marketing and education. We are presently developing a comprehensive presentation on attic ventilation and attic retrofits for reducing energy consumption. This will be an accredited continued education course designed for architects, builders, and code officials. This will be an important tool for the Parksite specialists in their efforts to further educate people in the industry on this overlooked topic.

bpENNOVATIONS is a Rutland, Vermont-based company with offices in Rutland and Bennington Vermont. AERIX is exclusively distributed by industry leader Parksite, servicing the building industry as a wholesale distributor offering a wide range of exterior and interior building materials.

For more information, call 1-877.475.9360 or visit www.bpennovations.com.

 D R Sales & Marketing is a full service sales and marketing company servicing a variety of industries and specializing in building material manufacturers and distributors.