Sto To Present at D+D Material Selection Conference

VLC odor neutralizing coatings are one of the innovative products that will be featured including StoColor™ Climasan®  an interior wall and ceiling coating that will neutralize odors in the air when exposed to a light source. 

Durability & Design (D+D), the trade magazine focused on architectural coatings for the built environment, will be hosting a one-day Material Selection Conference, September 26,  2017 in Pittsburgh, Pennsylvania. The program is designed to help owners, architects, contractors and other building industry professionals determine the best coating systems to manage moisture intrusion into exterior walls, and the best liquid-applied air barrier designs to limit heat, air, and moisture transport through walls. In each of two panel sessions, a panel of industry experts, including manufacturer representatives, will discuss how their specific brands perform in different climates and indoor environments, and on different substrates. Sto will be presenting in both sessions – one focusing on coatings and the other on liquid-applied air barriers. Attendees should leave with a better understanding of the effect of permeance on exterior wall coatings; learn how to determine the performance, cost and cost-effectiveness of liquid-applied air barriers; and understand the advantages and disadvantages of specific coating brands that are candidates for use on their buildings. Attendees will qualify for 8 AIA learning credits for full-day participation and 4 credits for a half-day.

An Award-Winning Project that Includes StoGuard®

KHS&S is an international design-assist specialty contractor with a portfolio that includes more than 5,000 casino resorts, hospitals, hotels, entertainment venues, retail facilities, theme parks, attractions and public works projects around the country and overseas. Founded in 1984, the firm is now the second largest specialty wall and ceiling contractor in the USA. At the recent Florida Wall and Ceiling Contractors Association (FWCCA) convention and trade show in Orlando, the company picked up the award for Project of the Year for the work they did on Disney Springs, an elegant shopping, dining and entertainment complex at Florida’s Walt Disney World. A key partner in the KHS&S supply chain? Sto Corp, who provided wall components for two stucco buildings, that included products from its leading air and moisture barrier system: Sto Gold Fill® and StoGuard Mesh, Sto VaporSeal®, Sto TurboStick™ and Sto DrainScreen. Sto worked with Disney’s architects on the specification details. Now that the work is done, the results speak for themselves.

Building Better Walls PART THREE: Vapor Control & Thermal Control

Nike World Headquarters in Oregon where Sto VaporSeal® was used as an air moisture barrier.

The fact that many vapor barriers also retard or eliminate airflow sometimes causes confusion about the functions of the ABS and vapor barriers. The function of a vapor barrier is to control  water/vapor diffusion and reduce the occurrence or intensity of condensation. As such, a vapor barrier has one performance requirement: it must have the specified level of vapor permeance and be installed to cover most of the area of an enclosure. That being said, vapor control systems are either vapor permeable or impermeable membranes. Determining which type you need primarily depends on climate and wall design. There are a wide range of products and systems available today that employ formulations suitable for any climate. These will protect buildings from water infiltration in high-rainfall regions, as well as from water vapor drive and unwanted air movement. (Example: STO VaporSeal®) Fluid-applied, vapor-permeable building membranes are especially versatile, and may be used under a variety of mechanically attached claddings, including cement board, wood, vinyl, brick, stone and metal panels. Providing thermal comfort without overspending on excessive space conditioning costs is also one of the primary requirements of today’s building designs.. Therefore, thermal control is an important aspect in almost all buildings. Understanding heat transfer and the temperature distribution through building materials and assemblies is critical for assessing energy use, thermal comfort, thermal movements, durability, and the potential for moisture problems. The key components for controlling heat flow in building walls requires insulation layers that aren’t penetrated by thermal bridges, an effective air barrier system, good control of solar radiation and management of interior heat generation. So, in conclusion of our three-part series, a “clever” wall (we’ll even venture to say a “smart” wall), needs resilient design components that control air, moisture, vapor and thermal conditions. Get the wall right and it can make all the difference in creature comfort, energy efficiency and economics. Whether you’re retro-fitting or building from scratch, wall systems that can provide all four key controls are what you want.

Building Better Walls PART TWO: Air Control

The second part of our series on Building Better Walls focuses on air control and the basic requirements for air barriers systems in walls.

The management of airflow is important for several reasons: It controls moisture damage, reduces energy losses, and ensures occupant comfort and health. Airflow through a building enclosure is driven by wind pressure and the stack effect – movement caused by warmer air rising and colder air falling that create pressure differences. These, in turn, can lead to air leakage, unexpected airflows, and indoor air-quality problems. Mechanical air handling equipment such as fans and furnaces also impact air flow. A continuous, strong, stiff, durable and impermeable air barrier system is required between the exterior and interior conditioned space to control airflow driven by these natural phenomenon. Wall air barriers provide critical protection in all buildings, regardless of region or climate. Controlling air leakage within the building envelope also enhances a structure’s energy efficiency. Basic Requirements of Air Barrier Systems for Walls Typically, several different materials, joints and assemblies are combined to provide an uninterrupted plane of primary airflow control. Regardless of how air control is achieved, the following five requirements should be met to achieve a proper air barrier system (ABS): Continuity.  Enclosures are 3-D systems! Continuity must be ensured through doors, windows, penetrations, around corners, at floor lines, soffits, etc. Strength.  The ABS must be designed to transfer the full design wind load (e.g., the one-in-30-year gust) to the structural system. Fastenings can be critical, especially for flexible non-adhered membrane systems. Durability. The ABS should continue to perform for its service life. Ease of repair and replacement, the imposed stresses and material resistance to movement, fatigue, ambient temperature, etc. should all be considered. Stiffness. The air barrier must reduce or eliminate deflections to control air movement into the enclosure; it must also be stiff enough that deformations do not change the air permeance (e.g., by stretching holes around fasteners) and/or distribute loads through unanticipated load paths. Impermeability.  Typical recommended air permeability values are less than about 1.3 x 10-6 m3/m2/Pa. In practice, the ability to achieve continuous insulation is more important to performance; the air permeance of joints, cracks, and penetrations outweighs the air permeance of the solid materials that make up most of the ABS. Hence, a component should have an air leakage rate of less than Q< 0.2 lps/m2 @75 Pa, and the whole building system should leak less than Q< 2.0 lps/m2 @75 Pa. It is important to note that increased airtightness must be matched by an appropriate ventilation system to dilute pollutants, provide fresh air, and control cold weather humidity levels. Good airflow control through and within the building enclosure will bring many benefits including reduced moisture damage, lower maintenance costs, energy savings, and increased health and comfort.

Building Better Walls PART ONE: Moisture Control

The key components to building better exterior walls systems are: sheathing joint treatments, rough opening protection, transition membranes and an effective air/moisture barrier.

The moisture layer in an enclosure assembly controls the passage of water even after extended exposure to any moisture. The water control layer is the continuous layer (comprised of one of several materials and formed into planes to form a three dimensional boundary) that is designed, installed, or acts to form the wall’s rainwater boundary. In face-sealed, perfect barrier systems, this is the outer-most face of the enclosure. In concealed barrier perfect systems, it is a plane concealed behind the exterior face. In drained systems, the water control layer is the drainage plane behind the drainage gap or drainage layer. In storage reservoir systems, the rain penetration control is typically part of the innermost storage mass layer. Key components for moisture control in wall systems are: sheathing joint treatments, rough opening protection, transition membranes and an effective air/moisture barrier. Pre-formed drainage mats can also help remove water, as well as promote drainage and drying in vertical wall assemblies beneath stucco, stone, siding and thin brick veneers. (Example Sto DrainScreen) Fluid-applied, waterproof air barrier membranes in wall construction have proven their worth as excellent protection against moisture intrusion and air leakage, delivering thermal value in the form of significant energy savings in hot and cold climates. (Example: StoTherm® ci XPS) These fluid-applied air/moisture and vapor barriers may be used with all types of above-grade claddings and wall substrates. Trowel-applied air/moisture barrier and adhesives may be used for above- and below-grade walls and for attaching continuous insulation. Look for wall systems that provide seamless air and moisture control as opposed to building- wrap barriers that are typically penetrated by staples and fasteners for attachment. An entire wall assembly that provides seamless protection will provide reliable control layers for air and moisture intrusion. Wall coatings can also offer protection against moisture and rain, along with UV degradation, heat, salt, wind and humidity. Coatings with permeance can help resist blisters and mold in a wall cavity, which can be caused by moisture resulting from vapor migration. In addition to repelling external water and moisture, an advanced coating system can also help resist cracking and prevent corrosion in substrates containing steel. While every building is different and coatings will vary based on cladding types and other variables (such as regional climate), wall coating formulations today are not only weatherproof, but can offer vapor permeability, crack-bridging capability, and mold resistance; some are so high-tech they create a durable surface that both beads water and sheds dirt, thus self-cleaning a wall. (Example: StoColor® Lotusan®)  

Three Part Series on Exterior Walls

The science of exterior walls has been well-documented; look for our three-part series that starts next week.

Starting next week, ARCHITRENDS is launching a three-part series on building better walls, thanks to a big assist from the Building Science Corporation (BSC) – a consulting and full-service architecture firm for commercial, institutional and residential buildings. An internationally recognized organization, BSC’s focus is preventing and resolving problems related to building design, construction and operation. Probably best known for their expertise in moisture dynamics, indoor air quality and forensic investigations into building failure, BSC advocates for sustainable design, energy efficiency and environmental responsibility in building technology. Their website  is a free online resource. Better Walls for Buildings The perfect wall is an environmental separator—it must keep the outside out and the inside in.  Therefore, in a world of perfects walls, a wall assembly must control rain, air, vapor and heat. Functional, resilient walls need four principal control layers: moisture control layer air control layer vapor control layer thermal control layer As BSC points out, if you can’t keep the rain out, don’t waste your time on the air. If you can’t keep the air out, don’t waste your time on the vapor and forget about thermal. The perfect wall includes a water control layer, with an air control layer and vapor control layer positioned directly on the structure, and a thermal control layer covering the other control layers. Expansion, contraction, corrosion, decay, ultra violet radiation (basically, most bad things!) are all functions of variations in temperature. So, control layers need to go on the outside to help the structure weather temperature extremes and protect it from water in its various forms, as well as ultra violet radiation. The “clever” wall, as BSC calls it, uses building material that combines all four controls. Thus, air moisture barrier systems (AMBs) and exterior insulation finish systems (EIFS). The most “clever” walls utilize integrated, stand-alone systems that can work together to form a waterproof air barrier for all types of vertical, above-grade wall surfaces, engineered for fast, easy application. (Example: StoGuard) These continuous-insulation (ci) wall systems can provide superior air and weather tightness, long-lasting thermal performance, durability and are available in a wide range of decorative and protective finishes. Look for PART ONE in our series next week; it will focus on Moisture Control.