We will be taking them out of the box and then training on the use of the Ipad.  Snippies (www.snippies.com) will be on hand to video and prepare the promotional aspect for Box.Net.  This is the other part of the program.  The part that is most important to D 7 is getting the maximum efficiency out of the Ipad for our services in the Building Envelope Consulting business.

We are getting ready to embark on a new path of work flow.  What used to take days will now take hours and in some cases minutes.  Getting information from the field to the office and into the client’s hands has always been the most difficult part of our work.  Through Box.Net we will be able to have the information in the office before the Quality Assurance Observer or Consultant is back from the field.  Having this head start on the document(s) will save time immediately.  Not to mention the processing of photos (always a time consuming task) this can be tedious and confusing.  We will now be able to have immediate access to photos from the field.

So if you are a client who wants quick turn around, look no further than D 7 Consulting.  This will be what we do best.  Combined with our technical ability, years of experience in the roofing and waterproofing business and top notch staff of experts, why would you look elsewhere?

Hot fluid-applied rubberized asphalt;
Cold Fluid-applied urethane coating;
Single Ply;
Built-up asphalt roofing;
Modified Bitumen roofing;

Obviously, some are better than others. Some offer more advantages versus others. The main thing to understand is why you would utilize this type of membrane assembly.  In most roofing system, you install the insulation over the substrate, followed by the “waterproofing” membrane, with the surfacing (as in BUR or Modified roof systems).  With a single ply, the membrane is the first and final layer or surfacing. With the two fluid-applied systems, you would not see these in the more tradition roofing systems and they only come into play with the IRMA or PRM because of the covering or protection. Lets talk about what happens after the roof system is installed over the insulation. In time the building will have foot traffic, maintenance, equipment change out, typically atmospheric degradation such as sun, wind and rain. All of these are constant and cannot be taken out of the factors that affect the service life of the membrane. With the normal roof system, the traffic on the membrane eventually affects the service life. When water is allowed to enter through the membrane from any deficiency, then the insulation can now be affected.  Finally, finding the leak becomes problematic due to the fact that where the water enters the membrane and where it shows itself in the building can be two distinct locations. Maintenance or repair to the roof system may involve extensive testing via Infrared scanning or destructive testing by opening up the roof system to determine how wet or deteriorated the insulation is located. Both of these are costly and time consuming, not to mention the affect it has on the overall system. When leaks do occur within an insulated system, we have seen a lot of repairs performed without doing the homework to find out what has happened to the materials below. The roof may still leak, the wet insulation can still be holding water and worse yet, you have lost the insulating R-value due to the wet insulation thus rendering the insulation useless. The traffic also affects the overall service life. With a building that has a high level of equipment, maintenance and foot traffic the roofing membrane can suffer and the service life is shortened sometimes drastically.

So why use a IRMA or PRM system? Going back to the definition, we want to protect the membrane. How do you do that? Simple put it on the substrate (concrete in most cases) and cover it up so that it cannot be damaged. Start by installing the membrane over the structural deck. With all of the options listed above you want to “finish” the system meaning install the flashings, surfacing or protection sheet over the roofing/waterproofing membrane. This system can be worked over, walked on, even construction can occur after the roof membrane has been placed. In new construction, this allows the building to be watertight much earlier in the construction period so that interior work can move along faster than normal. As they say in the construction trade “Time is money!” Now that the membrane is in place, what is next? Now the insulation can be placed over the membrane. Except this is where the biggest change takes place. The typical roofing insulation is Polyisocyanurate insulation. To make it simple, this type is not suppose to be exposed to the elements. So you would not use it in an exposed assembly. EPS (Expanded Polystyrene) or bead board or “Styrofoam” is another typical roof insulation. This also should not be used in an exposed manner. So what can you do? When using an exposed insulation, you would utilize an EXPS or XPS or Extruded Polystyrene. One location to learn more about this type of insulation is www.xpsa.com.  You will learn that XPS insulation has more R-value per inch than traditional insulation. It is resistant to moisture, which is why it is used in this type of assembly.
It has greater structural capacity or basically is stronger. It is and can be used in many locations on your building. I recommend reading more about it as an option for insulation when designing systems.

So once you have the insulation protecting the membrane, what do you do then? Well the insulation has to be held in place. Otherwise wind can literally blow it away. As in traditional systems, you have to provide a surfacing. The surfacing of an IRMA or PRM provides two benefits. 1) Holds the insulation in place; 2) Provides a walking surface. Now there are other components such as flashing membranes and drainage board, filter fabric and insulation tape for joints, but a “Design” blog is for later. This is for bestowing the basic principle of the IRMA roof system. The two components used are typically rock or ballast and concrete as in pavers or poured. In both cases, the most important factor to consider after the membrane of course is Wind Uplift. With all roof systems, the wind uplift should be reviewed so that you meet the local requirements and do not allow a wind failure to occur. By providing the correct amount of ballast per square foot (Typically 15 pounds psf for the perimeter) you will meet or exceed FMG I-90 wind uplift rating. (FMG stands for Factory Mutual global). When using pavers, the typical paver size is 2′x 2′ x 2″, any larger and the handling of the paver becomes difficult. The paver is used in window washing locations, foot paths between access and equipment, etc. The ballast is used in the field areas where foot traffic does not occur or is not required.

Now you can see the one thing that stands out on this type of assembly. For me it is simple. If I get a leak, I don’t lose my insulation. I can remove the materials over the membrane, find the leak location due to the fact my membrane is fully adhered to the substrate, provide repairs and put the materials back into place. Finally, the wear and tear on the membrane is eliminated, thus reducing long term maintenance costs. Remember I also have a greater thermal envelope on my building due to the higher R-value per inch. There are so many advantages to this type of system I could on and on. However, it does have one thing that keeps it from become more widely used. The Cost! The ballast and pavers are costly, the insulation is typically more expensive and if you are using the hot rubberized asphalt
system, that too can be more expensive. We would recommend a Life Cycle Cost analysis for anybody considering the use of this type of assembly.

I first became interested in this type of system when working with SOM(Skidmore, Owings & Merrill) in Los Angeles, CA. Their firm has been around since 1936 and began in Chicago. The IRMA or PRM system is a staple of their designs. If you go up on a building that has ballasted insulation, membrane below and walkways of either pavers or concrete, you are most likely on a SOM designed building. Go to their website www.SOM.com and you can learn more about them.

So what do we know? If you protect the waterproofing or roofing membrane it will last longer. If you utilize an insulation that does not break down under water, you won’t have to worry about the weathering of the insulation. If you use a solid walking surface, you won’t have to worry about damage to the membrane or insulation. All of these add up to greater service life and lower maintenance costs. So protect your investment and begin protecting your roof. You can’t go wrong.

Let us start with Definitions. What is an Air Barrier?
According to the Air Barrier Association of America (ABAA) by definition, air barrier systems are a component of the building envelope systems that control the movement of air into and out of buildings. There are many types of air barriers to choose from, and there are many important factors to consider when determining the best barrier.

Different Types of Air Barriers: Fluid-Applied
One of the new systems being utilized more today is the fluid-applied waterproofing/air barrier. What is not known by most is that Fluid-applied waterproofing/air barriers have actually been manufactured in North America for more than 25 years. It is only recently that their use has increased as air leakage has become recognized as a potential source of moisture accumulation in walls, and some of their unique benefits have been realized.

Much like fluid-applied waterproofing membranes, Fluid-applied waterproofing/air barriers are rolled or sprayed onto substrates and become part of the structural wall. Because of the way they are applied, there are no fastener holes where water penetration may occur, and there is no potential for improper laps or tearing, as with many sheet goods. During construction, a fluid-applied barrier will cover the substrate completely, and does not have to be covered immediately with a cladding, as many of them are UV-resistant.

Another important distinction of a fluid-applied waterproofing/air barrier in wall assemblies is that it can mitigate one of the major forces that causes water infiltration into walls: pressure difference. A fluid-applied waterproofing/air barrier, in combination with venting and compartmentalizing, enables the pressure behind the cladding material to equalize with the pressure outside. This prevents rainwater penetration caused by pressure differentials. This pressure equalizing effect is only possible when the air barrier is structural, as is the case with fully adhered fluid-applied waterproofing/air barriers.

As discussed by Lisa Petsko, a Sto Guard Associate Market Manager, for the Sto Corp. in the Masonry Magazine, “by designing and constructing an “airtight” building envelope, the risk of moisture problems — mold growth, decay, corrosion, loss of insulation value and Indoor Air Quality (IAQ) problems — that can occur because of air leakage and condensation are minimized.” Another good reference can be located at www.buildingscience.com This is a great source for information on Air Barriers.

I know that all of these items are on the list of goals to be achieved when design and specifying the air barrier for a project. Seeking out the best fit for the project is always the challenge due to the variety of choices. None of them clear cut at first glance.

Different Types of Air Barriers: House Wraps
We all have seen the more common air barrier, House wraps, or sheet good type systems. These materials are usually applied under a home or building’s veneer and over the substrate, such as CMU, plywood, gypsum sheathing or in some cases, insulation board. It is important to consider the climate when selecting one of these types of air barriers. Some of the key characteristics include; Better weathering capability, some are more water-resistant than others, and some are more resistant to tearing. They come in a variety of sizes for different purposes. They are wrapped around the exterior of a building during construction and cut around windows and doors. Self adhesive house wrap tape can be used to seal the joints/laps, and flashing is applied at openings and penetrations. Unlike fluid-applied systems, the method of lapping, sealing and incorporating flashings become a bit more tedious, but critical to the overall performance.

Vapor Barriers are not to be confused with an air barrier. A vapor barrier is designed to restrict the flow of water vapor through a material, just the same as an air barrier material restricts the flow of air through a material. Vapor barriers or vapor retarders are intended to control the rate of diffusion into a building assembly. A vapor barrier will control the rate of moisture flow where they are placed. Therefore the vapor barrier does not have to be continuous, does not have to be free of holes, does not have to be lapped, does not have to be sealed, etc. A hole for example in a vapor barrier will simply mean that there will be more vapor diffusion in that area compared to the other areas where the vapor barrier exists.

Selecting an Air Barrier:
Which one should you choose? That is the big question. In today’s world cost is the ruling factor. However, with the competitive nature of the systems and the similarity of all the systems it is still important to identify the one that will work best for you regardless of cost. As a designer it is critical that you review all the components and choose one that addresses all the potential issues for the project. Code compliance is critical to understand. Cities and or government requirements dictate the use of Air Barriers in many cases. Make sure to check with the local building officials and verify what is required prior to writing or specifying a material.

Checking to see whether the Air Barrier has been tested and approved for the area where the project is located is important. Reviewing systems that have been approved by the Air Barrier Association of America would be a good place to start. Listed below are the materials which have been through the evaluation process as performed by the ABAA. Note, this is not a complete list of Air Barrier products by any means. Just an example of the number of systems that you can start with. The chart is taken from the ABAA website www.airbarrier.org for use in understanding what they have done to evaluate the systems.

ABAA Listed Materials
Air Barrier Materials which have Completed the ABAA Evaluation Process can be found on this page.

To continue the thought, some of the following key design aspects should be considered when choosing the system for your project as offered by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Journal:

• Design the exterior envelope and its components to withstand the combined design wind, stack and fan pressures in an airtight manner.
• Design an air-barrier system into the building envelope that can take this pressure, both positive and negative, without displacement or failure. For areas within a building with significantly varying climates, include an air-barrier system into the separation between the two areas, such as between pools and offices, or humidity-controlled areas and adjacent uncontrolled areas.
• Separate shafts—elevators, stairs, ducts and atria—from the floors they serve by airtight assemblies. Provide vestibules and gasket doors and access panels to control transfer of stack pressure.
• Separate pollutant areas such as photocopy rooms, chemical or cleaning storage areas, toilets and garages with gasket doors, and make the surrounding partitions airtight at the deck and floor.

In addition, Wagdy Anis, AIA , LEE D AP, principal of Boston’s Shepley Bulfinch Richardson and Abbott, was quoted in the March 2005 issue of the ASHRAE Journal, recommending that the air-barrier system should be:

• Constructed of relatively air-impermeable materials and assemblies, interconnected with flexible joints.
• Continuous throughout the enclosure.
• Structurally supported to withstand positive and negative air pressures (including design wind pressures and gusts, as well as persistent low pressures such as stack effect and fan pressurization) without displacement or failure.
• Durable to last the life of the enclosure if inaccessible, or maintainable if it can be accessed.

In addition, Anis, who also chairs the Building Enclosure Technology and Environmental Council (BETEC ) of the National Institute of Building Sciences (NIBS), points out that the air-barrier system should be clearly identified by the architect in the construction documents on the building-enclosure details, with a strong focus on intersections of different enclosure systems and transitions. “You have to be able to trace through from one identified plane of airtightness in the first assembly through a sealed joint to the plane of airtightness in the adjacent assembly,” Anis explains.

In general, it’s important to emphasize the fact that the building envelope is part of the mechanical system, even though it is designed by architects (who may not be aware of this) and built by contractors (who may not be particularly focused on airtightness). That being said, we still need more education, greater knowledge and much more informed collaboration about this critical function of the building envelope to the continue to expand on the best practices principles.

Conclusion:
As you can imagine, having just read through this information, there are a myriad of thoughts, recommendations, guidelines and even code requirements that need to be understood. Do not choose lightly. Be diligent in verifying which system will be best for your project. Seek out the experts. As I indicated above, nobody got out of bed this morning with all the answers. What we do know is that with the properly designed and installed Air Barrier system for a project, it will provide significant benefits including energy savings, moisture control, HVAC efficiency to name a few. In today’s market using the proper system will save dollars in the long run. So don’t be afraid to spend a few on the upfront cost of design and installation in order to save long term cost in the building maintenance and management.