Is It Really a Leak? - Feature Article - Walls and Ceilings

Is It Really a Leak?
by Vicente Montes-Amoros LEED AP BD+C
October 28, 2010
This and the next two pictures show condensation accumulation on the glass’ inside surface.  This is very common in monolithic glass applications used in the past.

When it comes to thermal insulation and weatherproofing there are many factors involved, and it is not easy to point fingers to see who is going to pay for the bill in a leaky building. Sometimes, the waterproofing system has been blamed for any type of leak related issues. But the fact that water is manifested in the interior of the building is not always due to a lack of detail or design in the waterproofing system.

Water can manifest in the interior walls when the temperature drops below dew point or when vapor pressure rises above saturated vapor pressure at a given temperature. When this process is visible to building occupants, it is called condensation.

This and the following two pictures show condensation accumulation on the glass’ inside surface.  This is very common in monolithic glass applications used in the past.Surface condensation is the process whereby water is deposited from air containing water vapor. For this to occur, factors like temperature and moisture content need to occur at the same moment. Surface condensation is not only associated with cold or humid climates, it can manifest at room temperatures as high as 60 degrees Fahrenheit (if the room temperature drops from 80 degrees Fahrenheit at 50 percent relative humidity, for example). Therefore, it may happen in any project when the wall’s thermal behavior has been overlooked or not designed properly. On other occasions, the thermal behavior has been addressed but interfaces between adjacent systems were not analyzed.

Another area to look closely at are systems transitions. The transitions’ response to a bad design will be condensation in the first place; but problems related to severe heat loss can also occur. This phenomenon receives the name of thermal bridge.

Thermal bridges occur when two different materials with relatively high thermal conductivity differential are installed next to each other, or when a single member is exposed to a high temperature differential (single curtain wall framing members that are exposed to the exterior and interior of the building with no thermal break or treatment, are a good example of this).

Condensation Consequences

Consequences from condensation are well known within the industry such as: mold growth, dampness, wall paper peeling, insulation decay, corrosion, pattern staining, etc. The good news is that these issues can be minimized if the system’s thermal behavior is checked or modeled. This way, any potential problem can be addressed. The technology now exists, where with accuracy and precision the condensation issues and thermal bridging can be predicted and avoided. And generally, this engineering cost cannot even be compared with the cost of having to repair a problem caused by these factors.

If there is a potential issue, surface condensation is going to be visually evident during the building’s service life. But there is another type of condensation that generally is not so evident and can occur between the wall layers. I am referring to interstitial condensation. This type of condensation works on the same principle of material temperature and dew point (but it involves many more factors since it depends on materials resistance and interfaces behavior between them). 

Interstitial condensation can become a problem if the wall’s air cavity is too small to allow some air movement or if thermal insulation is insufficient to prevent heat loss. The problem is that it can take several years before we notice the problem. Draining the cavity is also very important, as well as moving this drained water, in a controlled manner away from the building.

Determining if you need to check the thermal behavior of your project is not complicated. Remember that all projects and building functions are very different from each other. It can be said that if your project is in a relatively stable climate with a constant temperature all day long, with a relatively low humidity, little or no artificial-ventilation or no vegetation around, and with the perfect cladding system, then and only then your project could behave fine, thermally speaking. Even if all these factors are met, there is a chance that in the near future, the building use or the climate will vary, and then the problems could arise.

What Needs to Be Done?

A good start is always to define the wall construction, the wall elements and the arrangement of the elements within, and then run a thermal analysis. After this analysis, and depending on the results, thermal bridging must be eliminated. An optimum size and efficiency should be chosen for the insulation, and perhaps, lower the vapor pressure inside the building. Each of these solutions has several options and they are system dependant.

The illustrations in this feature show some thermal analyses performed on several types of cladding systems. All of the images shown are for illustration purposes only and do not represent any particular solution.

The detail shown in Illustration 1 is the transition between a curtain wall sill and a terracotta (masonry) system. This model was built to determine the surface temperature on the materials and investigate the potential for surface condensation. Right below the curtain wall frame, the temperature is 45.2 degrees Fahrenheit. If the interior dew point temperature was equal or higher than this value, then, condensation will occur. On the other hand, if the interior dew point temperature is 37 degrees Fahrenheit, for example, then there is no condensation problem.    

Even with the temperature gradient shown in the illustrations, some of the wall elements can appear to be below dew point. It does not mean that condensation will occur since the scope of these models is to show surface temperature only. For interstitial condensation, there is another type of calculation.

Constant condensation might damage adjacent materials, and depending on the frequency, it might even cause corrosion of metal.For Illustration 2, it can be seen that the inside temperature is relatively low due to the lack of protection from the outside environment. There is only a thin metal cap at the underside of the framing member. Due to this, cold temperature is drawn towards the inside of the building. It is most likely that surface condensation will form along this entire framing member, unless the detail is modified or thermally improved.

Making changes to a wall in order to improve its thermal behavior is sometimes inexpensive and can save thousands of dollars in repairs, if detected and addressed before construction. Hence, it is greatly encouraged to review the thermal behavior of walls for every project and if possible for every detail in the building envelope system.

The next time you see water inside your building, think twice before tearing off your interior finishes trying to find the source of the leak; there is a chance its source is not water infiltration and you will end up paying to repair your finishes. Also, before looking for the contact information of the “responsible” contractor and calling them for a repair, there are many factors related to thermal behavior that need to be evaluated to confirm the cause. The problem sometimes lies in the design. There are many inexpensive alternatives to resolve this problem without having to completely refurbish your building. So next time, ask yourself the following: Is it really a leak?

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2010's Most Requested Products - Feature Article - Walls and Ceilings

2010’s Most Requested Products

December 1, 2010

For the past 12 months, the readers of Walls & Ceilings have told us what products and literature were of interest to them by filling out the reader action cards. Tallied from hundreds of entries, the following have appeared in the Product Focus and Toolbox departments. In no particular order, here’s what you told us you found of interest. 

VOC Reducing Wallboard

CertainTeed Gypsum

AirRenew gypsum board is a patent-pending product that provides strong protection against mold and moisture. The wallboard actively helps clean the air by capturing VOCs—formaldehyde and other aldehydes—by converting them into inert compounds that safely remain within the board. The product also features M2Tech technology, which is specially engineered to provide enhanced protection against moisture and mold. In addition to improving indoor air quality, the board is designed for fire resistance. It will help meet the VOC concentration limits, mold resistance, and recycled content criteria recognized by the U.S. Green Building Council’s LEED certification program. The board will soon be available for sale across the U.S. and Canada.

Spiral Saw Technology

RotoZip

The RZ2000 uses Constant Speed Control circuitry to maintain speed under load. For more accurate cuts, the tool’s electronic feedback control and low vibration combine to make accessories cut more smoothly at an even speed. To increase user intuitiveness and streamline use, the company developed the RotoZip Connect attachment interface. This feature provides a quicker, more secure connection than previous designs and ensures that heavier duty attachments, which could potentially damage older tools, are only used with the RZ2000. The company updated the “bump” switch to a front-mounted slide switch. The product’s repositioned on-off switch, which works like the switch on a typical angle grinder, creates more comfortable ergonomics for easier use and increased precision. An adjustable handle strap allows users to maintain a comfortable, steady pace for cleaner cuts while Soft Start reduces initial torque for enhanced control.

Miterless Molding Systems

Fypon

Miterless Molding Systems eliminate the need to make time-consuming mitering calculations and cuts. Fast end-to-end installation of urethane moldings require no seam match-ups and no special cuts. Decorative divider blocks enhance the overall room design while eliminating the need to seam molding lengths together. And, for corner areas, pre-mitered inside and outside corner pieces add style to the room while requiring only a straight-cut, butt-edge fit. The one-piece moldings are lightweight, come in a wide variety of styles and in lengths up to 16 feet for faster installation. The systems can be installed with premium adhesive and nails. Pieces can be painted after installation and resist humidity, warping and splintering.

Close-cell Spray Foam Insulation

Johns Manville

JM Corbond III is a premium high-yield, closed-cell spray foam building insulation. The product can be installed alone or in combination with JM Formaldehyde-free fiberglass building insulation as a hybrid “system” to create custom insulation solutions that meet high demands. The products benefits include: The insulation provides an R-19 (R-18.6 aged value) when installed at a thickness of 3 inches, and offers up to an R-38 (R-37.2 aged value) when installed at 6 inches.
It offers the highest yield of any closed-cell foam building insulation, providing 5,000 to 5,200 board feet of coverage per set.
Due to the reaction temperature of the product’s two primary components, it sprays at 3 inches per pass, allowing for greater productivity.
Offers outstanding cold-temperature installation performance and can be applied in temperatures as cool as 25 degrees Fahrenheit. 
Because the material is a solid cellular plastic, it achieves complete climate isolation between outside and indoor environments.

Standard Wood Grille System

Armstrong Ceilings

The WoodWorks family of ceilings now includes the WoodWorks Grille. The new addition provides architects and interior designers with the opportunity to define the look of a space while enhancing both design and acoustics with the look of solid wood. The product is available in two standard blade heights, 1³/8 and 2¼ inch, and four finishes of Maple, Light Cherry, Dark Cherry and Walnut. The standard blade width is 5/8 inch. In addition, the new ceiling system is offered in 1-foot-by-8-foot panels with either 6 or 8 blades per foot. Custom options include blade height and/or width, finish and number of blades per foot. Finish trim accessories and a faceted curved system are also available. In addition to its aesthetics, when backed with a 1-inch thick acoustical infill, the system has a Noise Reduction Coefficient of 0.90, meaning it absorbs 90 percent of the sound that strikes it.

Decorative Moldings

NMC America Inc.

This line of wainscoting tongue-and-groove moldings are part of the Wallstyle collection and are made out of a patented, high-density polymer system, which is humidity- and impact-resistant. It is an environmentally friendly, microcellular foam that is recyclable and contains no formaldehydes or PVC, according to the manufacturer. All profiles are lightweight and pre-primed. They consist of two different profiles and vary in style, finish and width.

Spray Adhesive

Phillips Manufacturing

The new gripSTIK spray adhesive is a high-tack, multipurpose web-based spray adhesive ideal for adhering vinyl cornerbead and trim to drywall. This web-based spray adhesive features an adjustable nozzle for desired spray strength and width, making any job easy and precise. The spray adhesive works great with vinyl cornerbead and trim product lines. This product is available in 17-ounce cans and is shipped in cases of 12.

Rasping Jab Saw

Milwaukee Electric Tool Corp.

The company’s Rasping Jab Saw is part of its new line of hand tool products. Eliminating the need for separate rasping and reaming tools, the new saw utilizes grating holes along the side of the blade to rapidly expand holes or smooth rough edges of drywall after a cut has been made. To combat the likelihood of the blade bending or breaking, the tool features a durable 6-inch plaster/drywall blade available on the market. The saw also features rubber over the mold to increase comfort and prevent hand slippage. The tool is backed by a limited lifetime warranty.

Texture Sprayer

Titan

The PowerTex Texture Sprayer allows contractors to make easy work of touch up work or small projects such as a closet or bathroom. The tool doesn’t need a compressor—it’s powered by a high-speed air turbine and plugs into a standard 15-amp wall socket. It comes equipped with three spray nozzles, allowing homeowners to choose the right spray nozzle cartridge for the job and achieve optimal results such as popcorn, knockdown or orange peel. The nozzles are part of the Lock ‘N Go Assembly and are easy to remove or change. With its patented Lock ‘N Go technology, a simple twist releases all “wet” parts from the texture sprayer. The used parts can simply be disposed, or rinsed for re-use. The tool offers variable flow and sprays standard texture materials including: aggregated, unaggregated texture and diluted joint compound for a textured, high-quality finish. The two-position, 1-gallon hopper can be configured to spray walls or ceilings without the use of adapters. 

Continuous Insulated System

InSoFast

The company’s panels are engineered to provide continuous insulation with built-in attachment for a variety of building applications. The panels include a drain and dry surface on the backside, an integrated grid of wiring chases, and a fully insulated stud. These integrated studs maintain continuous insulation without creating a thermal short circuit. They also provide two options for attachment, adhesive or mechanical fastening. The design allows for a more controlled cost on labor and materials with typical installation rates four times faster than traditional framing alone. The thin profile offers a valuable space saving alternative.

FSC-certified Wood Ceiling Panels

USG

The FSC-certified True Wood Ceiling Panels portfolio consists of more than 200 products. The panels feature a natural wood veneer laminated to a medium density fiber board. This provides the warmth true wood with a Class A fire-rating and durable panel that remains dimensionally stable and crack resistant over time. The portfolio includes perforated options with the company’s AcoustiBond backer for high performing sound absorption. The company also offers a FSC Chain of Custody dealer certification program for securing FSC-related LEED points. 

Compound Mixer and Stirrer

Prazi USA

The StirWhip Mixer and Stirrer allows the user to quickly mix or stir liquids, paints, glues, epoxies, compounds and concrete smoothly and evenly. Durable and flexible it will even fit through a 5-gallon pouring spout. The design reduces strain on the drill’s motor. The product comes in two models: the 8-inch, 1 gallon model PR-9808 and the PR-9818 18-inch, 5-gallon model.

Building Envelope System

Henry Company

The Blueskin VP combines the technical performance of a commercial air barrier system with the ease of application of a traditional housewrap without the need for mechanical fastening. The product is a fully integrated, self-adhered, vapor permeable air and water barrier membrane. This product provides a method to completely seal the building enclosure to control air leakage while maintaining a continuous drainage plane with excellent breathability. Meeting ASTM E2357 for Air Barrier Assemblies, the system is a water resistive, vapor permeable, air barrier membrane backed with a patented permeable adhesive layer. It is easily applied to walls, transitions and around wall openings. It is applied in a “weatherboard” fashion using simple hand tools and without the need for mechanical attachment. Owners will benefit by increasing the thermal performance of their buildings and by eliminating the risk of air leakage attributed to the likelihood of mold formation. 

Interior Fiberglass-faced Panel

National Gypsum Co.

As a fiberglass-faced mold- and moisture-resistant gypsum panel, e2XP Interior Extreme can be used in a variety of interior applications that have the potential for extreme conditions. The product is well-suited for use in pre-rock applications, interior perimeter applications, owner or architect specified interiors and higher humidity areas. The product is comprised of coated glass mat facers and an enhanced core and can be used in both commercial and residential settings. The panel is lightweight, scores and cuts easily and is specially coated on the front, back and sides for easy handling. It is produced in 1/2-inch regular and 5/8-inch Fire-Shield Type X, 4 feet wide in standard lengths. The product has achieved GreenGuard Children & Schools certification for meeting emissions limits for indoor air quality. The product features a 12-month, weather-exposure limited warranty and is backed by the company’s customer service.

Insulated Acoustic Fabric Membrane

Birdair, Cabot Corporation and Geiger Engineers

Tensotherm is ideal where significant acoustic dampening is desired or required. The product can block out the sound of a jet taking off, or hold the sound of rock concert inside. The product’s sound attenuation ability is due to its Nanogel aerogel core and interior PTFE-coated acoustical membrane liner. It consists of Cabot’s Nanogel aerogel sandwiched between two layers of structural PTFE fiberglass membrane. This creates an insulated, energy-efficient inner layer that maintains translucency and promotes natural daylighting. The fabric is less than 50 mm thick, yet it more than quadruples the thermal insulation performance with a value of R-12 and natural light transmission value of 3.5 percent. This fade resistant material also offers maximum moisture control and superior sound insulation.

Textured Acrylic Surfacing Systems

BASF Wall Systems

These surfacing systems are designed as a complement to insulated concrete forms. Using the same basecoats, mesh and finishes that work over EPS boards, these systems provide the look of stucco in a wide variety of colors and textures. These systems can also be custom made to replicate the looks of natural stone, brick and even metal panels. They are designed to deliver crack-resistant flexibility and dirt resistance. According to the manufacturer, they don’t peel, flake or chip and are fade and abrasion resistant. 

Bullnose Cornerbead

Trim-Tex

The new Mud Lock Technology is revealed with the new Mud Set Bead Product Line. These cornerbeads feature patented Mud Lock Technology with 350 percent more bonding surface at a lower cost. Mud Set Beads will not dent or blister and absorbs extreme impact. The engineered hole pattern allows excess mud to flow through and quickly self level the bead, saving time and money. All beads are rust proof and do not promote mold growth. Mud Set Bullnose Corner Bead perfectly matches all 3/4 inch R. Bullnose Archways, accessories and tools. Mud Lock Technology ensures no cracks or callbacks and is compatible with most hoppers and roller tools.

Hot Knife Kit

Demand Products Inc.

The Craftsman Hot Knife kit includes the Hot Knife, which has a variable control with 16 heat presets, an on/off trigger, two sizes of blades (4 inch and 6 inch), a hex wrench, wire cleaning bush and padded carrying case. Many first time users who buy Hot Knifes don’t realize that several extras are necessary for production. The Craftsman kit eliminates having to order a second time just to have the right accessories. Several creative shape wire accessories are available. This complete kit has everything the contractor needs including the case, plus it has 150 watts.

Drywall Patch

Wikaru

The Wikaru Drywall Patch puts a brace behind the repair, making it stronger than the original drywall. For all intents and purposes, this becomes a permanent repair. The product is flush to the wall being repaired rather than on top of the wall. This drastically reduces the need to feather joint compound and texture to make the repair blend in. The patch also minimizes feathering, allowing amateurs to create professional looking repairs. The Wikaru braces and packaging are made in the U.S. out of 100-percent recycled materials.

2010 Product Catalog

Wind-lock

The 2010 catalog offers a comprehensive guide to the company’s product offerings in one place. Users can now locate what they need from Wind-lock in one, segmented catalog representing the primary business segments: EIFS/stucco/stone veneer, ICFs/SIPs, weatherization, Stealth Access Panels and Black Lab Apparel. The company is increasing its focus on offering a variety of weatherizing products to complement Dow products that can now be found in the Weatherization section of the catalog. In addition to new products, Wind-lock has developed “Ultimate Kits” for EIFS and ICF contractors. Accompanying product descriptions provide important technical data, benefits and application information. Products that have corresponding videos on YouTube are uniquely marked. Catalog copies can be obtained by visiting the Web site and clicking on “e-catalog” to download PDFs, or “Request a Catalog” to have a hard copy sent.

Dual-plane Line Laser

Bosch

The GLL2-80 is capable of projecting constant lines on both vertical and horizontal planes, ideal for alignment and leveling applications when installing wall tiling, drop ceilings, interior framing, decorative finish and trim work and more. For specific applications, the tool quickly switches between dual-plane, vertical-only and horizontal-only modes. The laser features Cone Mirror Technology, which reflects a laser beam to project bright laser “chalk lines” in 360 degrees, rather than using a motor to rotate the beam. By reducing the number of moving parts, the company is able to produce a laser layout tool that is more compact, lighter, easier to calibrate and simpler to use overall. Minimizing moving parts also means the GLL2-80 is significantly more rugged in typical job site use. Regardless of application, set-up is fast and simple for the self-leveling product. A secure transport lock protects the pendulum when the unit is switched off. Once leveled, the tool is accurate to within 1/4-inch over its 100-foot range (in normal mode). 

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About.com article about spray foam & allergies

Homebuilders Find Alternative Technology To Improve Indoor Air Quality
Allergies Blog

October 09, 2003
Homebuilders Find Alternative Technology To Improve Indoor Air Quality
The increased awareness of mold and other indoor pollutants has driven many homebuilders and commercial builders to find alternative technologies that can help improve indoor air quality.

There are increasing reports on mold problems with newer homes, schools and commercial buildings. The U.S. Environmental Protection Agency estimates that daily exposure to indoor air pollution can be two to five times higher than outdoor levels.

Indoor air quality can be affected by the level of ventilation and the types of building materials often used in homes, schools and office buildings. Mold growth should be considered a mishap, not an inevitable consequence of age. Such mishaps are fully preventable and entirely fixable. The more that is known about how to prevent mold growth, the more likely we are to build good buildings that stay free of microbial contamination.

The increased awareness of mold and other indoor pollutants has driven many homebuilders and commercial builders to find alternative technologies that can help improve indoor air quality. People don’t want to be in a home or building that’s polluted or moldy. If there is a way of building that will avoid indoor pollution and mold, we should be using it.

There are specific environmental conditions required for mold to propagate. A specific temperature range and source of food are the basic factors that must be in place, but the most important element is the presence of moisture. Moisture can be present within building walls, ceilings, attics, and crawlspaces via gravity, capillary action, air leakage and diffusion.

In order to minimize the potential for mold growth, a building envelope system has to meet specific criteria. Primarily, the building envelope must prevent water from penetrating. The components of the building should resist moisture and once wet should then have the potential to dry quickly (they should be hydrophobic). Therefore, the structure must be properly sealed and contain an effective drainage plane or rain screen. The building envelope must control air leakage. Uncontrolled air leakage leads to condensation and mold growth within the building envelope.

Of all the building materials used in a newly constructed building, insulation can have a major, long-term impact on the quality of the indoor air you breathe. With 40 percent of North American households having at least one family member who suffers from allergies or asthma, attaining maximum indoor air quality can be a major concern. "By sealing a building, reducing pollution sources, and controlling the air leaving it, we can greatly reduce the threat of airborne pollutants" said Bruce Small, director of the Envirodesic™ Certification Program (http://www.envirodesic.com), which independently tests and certifies building products that contribute to healthy indoor air.

One of Envirodesic™ Certification's premier products is The Icynene Insulation System®, a breakthrough spray-in-place soft foam insulation that totally seals a building with zero-emission insulation material. An Icynene Insulation System envelope is the ideal base for a healthy indoor environment, and is even suitable for construction for people who are hypersensitive.

"The Icynene Insulation System®, in tandem with mechanical ventilation, is a key to avoiding the growth of mold," said Mr. Small. More importantly, Icynene does not release any harmful emissions or fibers into the air. With the look and feel of angel food cake, the water-based foam does not emit gases known as volatile organic compounds (VOC) and contains no formaldehyde or harmful chlorofluorocarbons (CFC) or hydrochlorofluorocarbons (HCFC).

Source: PRWeb Press Release
09/29/03

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