Wall Water Barriers 101 – 2017

Emily Wychock, P.E.,  a Penn State AE alumnus, continued the tradition of presenting a Simpson Gumpertz Heger (SGH) lecture on the topic of waterproofing and water management to students in the Building Failures and Forensic Techniques class in Architectural Engineering at Penn State.  Wall Water Barriers 101 is a revised and follow up to the traditional and highly popular Waterproofing 101 seminar presented by SGH in the past.  This is the longest running visiting practitioner seminar in the AE 537 class.  Ms. Wychock covered the fundamentals as well as showing a number of case study  examples of her projects to reinforce the various lecture points.  Ms. Wychock covered design, construction, material defects and maintenance issues in her discussion.

Students interested in information that complements the SGH lecture may also want to look into some of the resources recommended by Michael Palmer, Building Envelope Specialist with Dow Building Solutions  who has lectured and consulted with AE  537 in the past.  Mr. Palmer recommends the following links for more information on wall control layers and related topics.

Another excellent resource recommended by Professor Parfitt related to this topic and building envelope design and  failure review in general is the Whole Building Design Guide.  More specifically, it is the Building Envelope Design Guide that relates to waterproofing.  The Building Envelope Design Guide is an excellent reference for this discussion post but it does cover a lot of ground from a topic perspective so you may have to be selective.  On the flip side, adding and relating information to this discussion should be fairly easy due to the amount of information in the guide (and associated references).  Students are encouraged to incorporate information from other sources as well as long as it has a bearing on the discussion.

Another good set of references that go into detail on a number of the items mentioned in the lectures, particularly the physical construction and inspection of wall systems are the  Brick Industry Association (BIA) Tech Notes.  In particular:

BIA Tech Note 7: Water Penetration Resistance – Design and Detailing BIA Tech Note 7b: Water Penetration Restance – Construction and Workmanship BIA Tech Note 7a: Water Penetration Resistance – Materials

The BIA documents explain some of the unique issues related to cavity wall construction that were mentioned briefly in class during our discussions and campus search for mass masonry wall structures.  This reference will be revisited by MKP later in the semester during the planned lecture on masonry movement joints.

Additional Related Publications for Background and Discussion

Two publications that also relate to this discussion topic of interest are:

Fleshing Out Flashing Options,” by Derek B. McCowan, PE, The Construction Specifier, November 2011.  You need to open and use / click on the icon for the article in the table of contents to skip to Page 18 for the full article.  The author is from SGH.

Flashing from the Masonry Perspective” by David Sovinski and Patrick J. Conway, CSI, AIA (both authors from International Masonry Institute), The Construction Specifier, February, 2008.

Built-in wall flashings– through-wall systems and the like– are often modified, reduced in quality or even partially eliminated as part of the value engineering (VE) process. Although these hidden components add little to the building’s visual appearance, wall flashings are essential parts of its weather protection system. Decisions made in the name of VE often provide very modest monetary savings when compared to the resulting degradation in reliability and durability.  That said, many field problems in this area are a result of installation problems or poor detailing…sometimes all of the above.

Featured Photo for this Post:

The featured photo for this post is the IST Building (Now officially renamed Westgate) on the University Park campus of Penn State.  Investigation of brick facade problems for IST by a forensic firm in conjunction with the Penn State Office of Physical Plant (OPP) revealed primarily construction related problems.  You can easily see from the photo or simply by viewing the building facade that the cost of repair of simple items such as brick shelf angles and flashing etc. is extremely disruptive and expensive.  Although you can’t tell from this photo, I believe that in at least some areas, the waterproofing and flashing continuity was disrupted and the flashing did not extend through the brick face…all items that Ms. Wychock warned you about as typical problems in maintaining a properly functioning cavity wall.

Tags: , , ,

38 Responses to “Wall Water Barriers 101 – 2017”

  1. cstefani
    September 19, 2017 at 9:41 am #

    From Emily Wychock’s presentation on waterproofing and wall systems, the success of a waterproofing system relies on the success of many moving parts. Just like with design, the success of a waterproofing design relies on proper detail design, specification, and installation. I would also argue, based on the case studies presented, that the success of a waterproofing design is just as crucial as the success of the structural design, from a replacement cost perspective. The cost to completely replace and reinstall a whole waterproofing can be prohibitive to an owner, making it important that it is designed and installed correctly the first time.

    In response to a question, Emily touched on the importance of the correct use and placement of vapor barriers. I would really enjoy if we touched on this more in class. I feel I have a grasp on the placement of the vapor barrier in hot and cold climates, but I am interested in how facade designers select the placement of vapor barriers in middle climates, if they place a vapor barrier at all.

    • mkev
      September 22, 2017 at 9:43 am #

      The PSU Alums at Dow have a good presentation on this. I will see if we can find a way to work them in prior to the end of the semester. Thanks for the suggestion.

  2. Perry H.
    September 19, 2017 at 12:32 am #

    Two summers ago I interned at a commercial roofing and waterproofing company and once a week I would go out into the field with a project manager to see what work had been completed and to make sure it was done properly. Some of the biggest problems that we ran into were simply a lack of care for the completed work by other trades. Once the waterproofing is set in place it could be some time before the final finishes are installed, so to help protect the barrier protection sheets or insulation board are placed on top of the water proofing. During inspections we found cases were the protection sheet had been knocked out of place and the water proofing membrane damaged. Even though we were able to catch some of these issues the seal losses some integrity and it can be hard to properly patch the breaks in the barrier depending on the material used. These sorts of problems are very simple but can cause serious problems later on in the buildings life.

    Other issues that we had on site were coordination with other trades. I remember one situation in particular where we had placed the water proofing membrane down on a roof and then in the next week or so a hole was punched through the roof and membrane for mechanical reasons. The entire area around the penetration then needs to be reworked. This shows the importance of sequencing.

    • benP
      September 20, 2017 at 9:05 pm #

      I too have experienced trouble with flat roofs and other trades not properly protecting the roof surface. We have a paper mill we service with about 1,000,000 sq ft of EPDM and TPO hat is in constant neglect. One of the biggest problems is walking mats were never installed for maintenance workers to properly access the rooftops. On the repair side, finding the leak in a membrane system can be a challenge. The holes can be very small and not easily found. Typically to find these small holes, we will have 4 or 5 guys crawling a small grid on there knees with rags and cleaner. Because of this, these little patches can be very expensive to the customer.

      • benP
        September 20, 2017 at 9:16 pm #

        The above posted before I wanted it to:

        For this same customer, we have an area above the manufacturing line that the metal decking has deteriorated from the steam made in the factory. The new decking that has been specked is stainless to help prevent rust. The logistics of this project will be challenging as to not shut the plant down while not letting debris fall into the assembly line. This will only add to the cost to the customer. These waterproofing problems cost the customers large amounts of money, I am curious to know what the one case study that Emily presented cost to repair where the brick had to be tore off the building, waterproofing properly done and the brick re-installed.

    • Shubham K.
      September 21, 2017 at 8:11 am #

      Perry,

      I completely agree with you that all trades need to work together in order to avoid failures. I think this is a common trend that we have seen across the board with building failures. Communication between trades is a critical concept that can prevent failures and ultimately save millions of dollars in repair.

  3. David K
    September 14, 2017 at 7:19 pm #

    Ms. Emily Wychock’s lecture brought about important points in workmanship. It is important for building owners to spend during the construction of their building’s facade examining the construction process. Many building envelope failures shown in the presentation were a result of poor workmanship. Many times, this included simply not following the details included in the construction documents. This in combination with Mr. Paul Parfitt’s lecture, amplifies the need for a watchful eye on the construction of a building’s facade.
    The next major point presented in Ms. Wychock’s presentation was understanding the possible responses of owners to a building enclosure failure. For example, in the presentation, one particular owner was told that the quality of the construction was low and many details, including that of flashing and vapor barriers, were not installed according to the details provided by the engineer/architect. The owner’s response in this case was only to repair the major problem areas to stop leaks, as opposed to a full repair or filing lawsuits. This decision could be made as a result of overall cost, and time since the building was constructed. If a problem with the enclosure presents its self many years after the building was completed, perhaps the owner is more likely to want to just have the problem fixed rather than to identify the party at fault.

    • Jeremy S
      September 17, 2017 at 7:32 pm #

      Dave,

      I completely agree that building owners should spend more time on quality assurance and the like. Even though we both know from personal experience that the job can be boring we also know that contractors and laborers can mess up. I dont think that building owners should be required to spend money and time in inspections but I do think that engineers and contractors should persuade the owner to.

      • David K
        September 20, 2017 at 10:12 pm #

        Jeremy,

        What contractors sometimes do, instead of hiring 3rd part inspectors, is assign “in-house” quality assurance professionals to their jobs. Some general contractors prefer to use this route if the owner does not specify the party performing the QA. I can imagine that this would cost the GC less than hiring a 3rd party QA entity but I cannot verify this as a reason without doing further research. Using an in-house QA technician raises the question of how many non-compliances are overlooked such to purposely avoid schedule and cost issues. The quality of the quality assurance may be put into question.

    • Jeremy S
      September 17, 2017 at 7:59 pm #

      The presentation given by Ms. Wychock provided me with more knowledge of building enclosure. It was useful knowing the advantages and disadvantages of typical wall systems. Even more interesting was learning different ways in which water can penetrate through the water barrier. In one example a masonry wall experienced excessive efflorescence due to salt being used in the mortar between bricks. The interesting part about this example was the amount of efflorescence which made the building look as if it was painted white. Another unique example that Ms. Wychock went over was the deterioration of a private homes exterior stucco. This was surprisingly caused by water penetration from the inside due to a high level of internal humidity.

      Ms. Wychock also answered questions that I have had since my internship over the summer. On one project I inspected the wall expansion joints and backer rods behind them. While knowing what a good or bad backer rod looked like I didnt know the function or purpose of a backer rod. Ms. Wychock also discussed the different advantages of different waterproofing systems. I thought that a sprayed on waterproofing layer was usually the best however it can be easily damaged and poorly installed.

      Overall the presentation provided more in depth information on the possible reasons that a facade fails. She also showed on site pictures of what each failure looks like. Such pictures were broken flashing, improperly sloped flashing, tears in the water barrier or improper overlapping of a stuck on membrane. Given the amount of information presented I am glad that this lecture has been such a tradition.

  4. Jared P
    September 14, 2017 at 8:54 am #

    In her talk on September 12th, Emily Wylock of Simpsom Gumpertz & Heger Inc spoke about the importance of proper instillation of wall membranes with in cavity wall systems. She referred to three membrane application methods in particular to discuss which were: Self-Adhered, Fluid-applied, & Loose-laid sheet. All of these methods have different factors for how well they preform as well as different advantages for use.

    Self-adhered, also known as “Peel and stick” is a sheet of membrane that sticks to the surface of the substrate. This membrane is effective at shedding water when constructed by the shingle method. The membrane needs to be fully adhered to the substrate and must have penetrations detailed otherwise water will find its way through the barrier.

    Fluid-applied membrane is applied as a spray or a rolled on material that forms a continuous water barrier on the substrate. The substrate needs to be properly prepped in order for the fluid to adhere. It beneficial to consider the sequencing of this process in order to construct the enclosure correctly.

    Loose-Laid sheets are the most commonly used product for residential construction. It is essentially a loose piece of plastic that is anchored with spacers and punched out around openings. The difficult part of application is creating a water tight barrier around the openings which is why overhangs or sunk-in windows/doors are typical in residential construction.

    Emily Wychock discussed briefly about each of these methods and mentioned that different buildings can perform differently for the same product. It is never a no-brainer how to keep the water out but it is understandable that water in the wall is bad. The water membrane is a critical part to water remediation and understand what methods are available is important.

    • Shangmi X.
      September 21, 2017 at 6:33 am #

      Jared,
      I agree that the methods are important part of waterproofing. Although there are these three backup wall membrane typical application methods, the workmanship of the application will be the key to success. However, the workmanship by people can’t be perfect which then need quality control to ensure the membrane is perfectly sealed and attached. Quality assurance is also required that if the applied product is under quality, then the perfect workmanship will be in vain.

  5. benP
    September 14, 2017 at 8:18 am #

    In my time spent in the field as a tradesperson, I believe a system similar to the tyvek housewrap type system to work the best. This system can be used up to 5 stories tall. A link to their install instructions can be found at http://www.dupont.com/content/dam/dupont/products-and-services/construction-materials/building-envelope-systems/documents/K16282-Residential-WRB-Install.pdf . I am a fan of this system mainly because it relies minimally on adhesives and tapes. This system relies on everything being shingle lapped. Shingle lapping is how people have been staying dry for thousands of years. Adhesives and tapes are a very new concept if we think of it from this perspective. When the tapes are used in this process, the adhesion is minimally relied on, as all protrusions are flashed starting at the bottom creating a shingle lap. Also, this system comes in long rolls, 150 ft long. This helps to cut down on the vertical seems that are needed. Horizontal seems are easier to waterproof as gravity helps us, vertical seems are trickier because water can follow a wrinkle right between the 2 layers.

    The one picture of the peel n stick Carlisle system that was showed in class pointed out this problem. Most sheets of the peel n stick are much smaller in size creating more of these seams. Also, anyone who has worked with material of that type knows that it stretches. This stretching is what then creates wrinkles. Wrinkles then create leaks when in a vertical seem, my opinion is that it is almost impossible to be 100% waterproof when lapping on top of a wrinkle in a vertical seem. This concept holds true in many facets of waterproofing whether it be on walls or roofs, wrinkles and bubbles are the enemy.

  6. HarryB
    September 14, 2017 at 8:09 am #

    During wall water barriers 101 one thing that struck me was that as the walls got more complex, from mass masonry, to barrier wall to cavity wall, there was more opportunity for the wall to be miss installed. For example, in order for a mass masonry wall to be water proof it only needs to be thick uncracked and the joints need to be properly done, while the water barrier in a cavity wall requires much more careful installation. Although, when installed correctly the cavity wall is a much more sophisticated and effective water barrier due to higher redundancy.

    • Richard T.
      September 20, 2017 at 7:14 pm #

      Harry,

      I agree with you that a mass masonry wall is simpler than that of a cavity wall in terms of waterproofing. In order to have an successful system for cavity walls it needs to be installed correctly.

      One thing that wasn’t brought up was if mass masonry walls had an advantage over that of cavity walls. Now that I think more about it the popularity of cavity walls may not all be due to their performance. Although there are performance perks, I think the popularity of these new wall systems is that it allows for Architects to be more flexible in their design. With the use of more glass in our enclosures, a load bearing wall becomes less effective.

    • Perry H.
      September 20, 2017 at 9:04 pm #

      Harry,

      This is an interesting point that you bring up. It seems as if the building enclosures technology is advancing much faster than the actual construction side of things and without both parts of the industry on the same level then the technology is all for nothing. The new systems that are being created are more complicated and have the potential to be more efficient but are much harder to install properly and the results of improper installation are exactly the opposite of what the new technology is set out to accomplish. On top of this the cost to fix the problems that occur due to improper installation are enormous.

    • Shubham K.
      September 21, 2017 at 8:06 am #

      Harry,

      I completely agree with you. With more complex technology, comes complex enclosures. I wasn’t aware that such complicated details go into detailing walls before being introduced to this topic. The cost and results of building a complex wall can be rewarding, but if it fails, then the cost to repair can be very expensive.

  7. Shangmi X.
    September 14, 2017 at 1:16 am #

    The lecture Emily Wychock gave us on Tuesday was very informative and gave me a very clear understanding about the wall water barriers. She covered three different types of the waterproofing systems which all have their own way of preventing water from the building and are designed to be very effective. However, the couple examples she showed us seems the water damage is a very common problem happened to be made over and over again.

    As we all know that water can very easily coming into the building So every building must having a very good waterproofing system. Some example she showed us was impressed me that even a little gap can cause a big damage to the building. In this presentation I noticed that most failure by water were caused by the improper installment. Simply applying water barrier or flashing doesn’t mean the building are complete safe from the water damage. As the couple examples in pictures, there are so many cases that the flashings were installed incorrectly which is not helping to let water out but leading water into the building which make the situation even worse.

    Walls as the most part of the building enclosure which should be paid more attention to it during both designing and construction. Detailing and understanding the wall system is very important which should leads to a perfect waterproofing. Therefore, testing is always needed to check if everything are installed correctly and to check if the system techniques are really doing their job to prevent the building from the water. I think a good waterproofing measure is a key to the long life of a building.

    • mkev
      September 14, 2017 at 10:57 pm #

      Good points Shangmi, especially about testing. Even when not required by the owner, some good contractors hire the forensic / facade firms to field test their work. This often starts with a mock up but in situ testing of a wall constructed during the normal course of work early on in the project can save the contractor a lot of money and catch problems before they get multiplied all over the building.

    • WangjaeY
      September 18, 2017 at 10:01 pm #

      Shangmi,

      I agree with your point in the importance of waterproofing. As Prof. Parfitt and most of guest speakers mentioned, the failures related to improper waterproofing causes catastrophic problems to the building and even the structure of the buildings. Architects and engineers should have proper understanding of waterproofing in enclosure.

      To Prof. Parfitt, how much do the forensic / facade engineers charge to field test?

  8. WangjaeY
    September 14, 2017 at 12:27 am #

    It was very informative lecture by Emily Wychock. I want to say thank to Ms. Wychock to provide valuable lesson on waterproofing systems. Water related problems are always stinky and bring many other problems together.

    The case study was very helpful that we can actually applied some stuff learned from her lecture. I have a question about the building in case study we looked at. Since there were a lot of places where waterproofing designs/systems were incorrectly constructed, how were the details on the drawing looked like? How can we say whom is more responsible if the details in the drawings are correctly drawn? or miscommunication between architects, engineers, and contractors? If drawings were correct, is contractor more responsible than engineers or architects? Who was responsible for taking care of the flashing details on drawing? Who was responsible to have an inspection on waterproofing detail?

    • Pete Pitilis Jr.
      September 20, 2017 at 9:47 pm #

      Wangjae,

      There were a lot of building failures related to improper construction of waterproofing systems. Improper construction can be caused by poor details, however, even in the event of a poor detail I’d like to think the contractor should be knowledgeable enough to understand the system they are constructing. For example, flashing being installed incorrectly. If the contractor would understand the purpose and function of flashing then I’d like to say they’d install it correctly even with a poor detail from the architect.

      To give some feedback on your question regarding who is responsible to schedule an inspection of a waterproofing system. In my experience, our CM had a quality control representative who would schedule a third party inspector who would then come out to the site and inspect the system prior to construction (a mock-up) and during. I was on a larger government project when this occurred so I’m unsure of when this process is required throughout all types of projects.

    • Geoffrey T.
      September 20, 2017 at 10:05 pm #

      Hi, Wangjae

      Technically, the details in the drawings are architect’s responsibility. However, that is why sometimes architect hires a firm like SGH to help them draw those details due to their expertise in building enclosures.

      Complete drawings do not mean that it will be constructed properly. Sometimes, engineers draw details that are impossible to be built. Thus, understanding of the system and how it should be constructed are very important. Thus, I think to help solve this problem, constant communication with contractors is important. Send them the drawings and coordinate with them through either simple mock-ups or ask their opinions about the constructability of the system.

  9. Keunhyoung Park
    September 13, 2017 at 11:41 pm #

    Through the lecture on Tuesday we witnessed type of walls and various possible problems by moisture’s infiltration. Ms. Emily Wychock gave a lot of visual examples and following explanation of the cases.

    As we know water proofing of building is very important for building because moisture is harmful to most structural frame and interior components. High humidity inside wall or floor cause outbreak of mold, leading to deterioration of indoor environment quality. Furthermore, most of building structure were built by using concrete and steel. And concrete can be suffer Alkali-Silicate Reaction or Carbonation due to ions in pervaded water. And steel will be corroded by oxidization with water. That means that building structure will lose their safety capacity due to infiltrated water will corrode core structure.

    For these reasons there are various wall types and techniques to achieve successful water proofing. Ms. Emily Wychock shows us typical type of wall such as mass masonry, barrier, cavity walls.

    Mass masonry wall is common type for low-rise building because the framing system does not need more complex techniques to build than other types. The masonry wall endure all load and take a roll of water barrier at the same time. By the way, as pointed at the lecture, masonry wall should secure enough wall thickness to perform as water barrier. If the wall is too thin, moisture will penetrate the wall by diffusing through the porosity of masonry. We learned the limitation of masonry wall due to its characteristic and keys to success to overcome the limitation. Surface Sealed Barrier Walls are more enclosed concept to repel the water at its outside. However, the wall have no backup water barrier. They often should rely on sealant. As my opinion, it look like that Cavity walls is designed to complement Surface Sealed Barrier Walls by including inner waterproofing layer. Although Cavity wall can be consider as advanced technique, there are also many possible problems.
    Backup wall membrane typical application method such as Self-adhered, Fluid-applied, and Loose-laid sheet have its own limitation and requiring procedures.

    Through the lecture I felt that water proofing techniques requires highly taking notice on them, especially the details of the system such as tilting angle, order of sheet’s application, or repair of punched site. Because water from outside will find even a tiny opening to infiltrate into the wall. So
    all workers from designer to field constructor should consider the detail of water proof system. If they do not, we may see the tear drops of the building over its wall.

  10. Tyler J
    September 13, 2017 at 7:52 pm #

    The presentation by Emily Wychock was informative and interesting. Water barriers is a topic not often discussed but one that can cause significant problems both structurally and in terms of cost. Mass masonry systems, surface sealed barrier walls, and cavity walls were all explained in great detail. In a mass masonry system, the structure is meant to be the water barrier. In a surface sealed barrier wall, the waterproofing membrane is completely separate from the structure and is designed to keep water out. Cavity walls are designed to allow water into the wall but are also designed to shed the water equally as fast.

    Some of the oldest buildings on Penn State’s campus contain mass masonry walls. Looking at these buildings, the majority have aged incredibly well. At the same time, many houses and buildings around town can be seen that have significant water damage, thought they are much newer. This makes me wonder the longevity of the surface barrier wall and cavity wall in comparison to the mass masonry systems.

    It seems that proper installation of these systems is key to their success. As others have mentioned, the industry as a whole needs to realize the damage that can be caused by improper construction of these types of walls. As mentioned by Emily, there is a procedure that needs to be followed during construction for a given system to work. If holes are drilled into a barrier after installation and not properly sealed, water will easily be able to find its way into the interior of the wall. Similarly, if flashing is not installed with the proper slope, or if it isn’t positioned to send water outside of a wall, it is not doing any good.

    • mkev
      September 14, 2017 at 11:02 pm #

      You are right Wangjae. It is possible that there is a lot of blame to go around on some of these cases. Even when a detail is show correctly, it may be only the most common and typical case. Drawings need to show the complex details like some of the examples shown by our last two speakers.

    • EllenW
      September 20, 2017 at 6:58 pm #

      Tyler,

      I also wonder at how the newer curtain and sealed surface barrier walls will hold up compared to mass masonry structures. Mass masonry buildings have stood the test of time, performing both structurally and in preventing water infiltration. The newer systems show wear and water damage after just a few years. This may be due to the fact that the shear bulk of the masonry wall provided redundancy in the water barrier and eliminated bridges for the water to follow into the building. As Ms. Wychock said, in newer construction there is no redundancy provided in the waterproofing design, so as soon as one small problem occurs, the entire system is compromised. Bridges are created when small tears are not patched or sealed and water can quickly pass through this unintended opening into the building. Perhaps a solution to the water barrier problem is to install two barrier layers with the joints staggered. This would provide redundancy, but the cost would need to be evaluated to check the feasibility of this solution.

  11. EllenW
    September 13, 2017 at 5:18 pm #

    Listening to Ms. Wychock’s lecture on Wall Water Barriers, it seems to me that there is a serious problem with waterproofing in the industry. Buildings with conditions similar to the case study presented are not uncommon. Flashing and detailing of waterproofing is a seriously overlooked component in design, detailing, and construction. These details are typically given to the architect for them to include in the construction documents. This is not the architect’s first priority and often falls by the wayside, resulting in incomplete or inadequate details. For example, the flashing drip edge is not included or does not extend through the wall far enough. Perhaps part of the problem is that the architects do not like the appearance of the flashing extending out to form a drip edge and they try to shorten the flashing to create a more pleasing final appearance.
    The next problem is, even if the waterproofing is properly detailed, showing the water barriers overlapping so the water can run over the joints and the flashing forming a drip edge, the contractors can miss these critical details. Some of the typical details, each showing a different condition on the building, can be overlooked or forgotten completely. Even with QA staff on the project, some problems are not caught in time. During my time with SK&A over the summer, I saw two projects where details were not followed during construction. One facade replacement project was installing ZIP panels. ZIP panels have a high R foam insulation interior layer with plywood siding coated with a water barrier on the exterior face. Once cut to size and installed, the joints between panels need to be taped with the proprietary flashing tape to provide continuity of the water barrier. On this project, tape was installed, however at the corners around windows the vertical tape was installed first and then the horizontal tape. This created a joint for water to run under the tape. I visited the site after a large rain storm and the tape, which had been installed the previous day, was already falling off the wall and had to be completely replaced. Luckily for this project the Superintendent knew that this was incorrect and had already instructed the workers to replace the tape, but on other jobs this may not be the case.
    Since problems with waterproofing are common, one of the first steps towards fixing the problem is to make all members of the industry aware of the problem and its consequences. Next, the correct practices should be explained as part of a standard or included as part of a design code so they are mandatory for every project.

    • Megan F.
      September 14, 2017 at 5:50 pm #

      Ellen,
      I agree members of the industry need to be aware of water infiltration problems and its consequences. Most, if not all water leaking problems can be avoided with proper waterproofing and construction techniques. This is why waterproofing details are crucial. Design companies should describe these details thoroughly and draw them in a simple and clear manner in order for the contractor to understand the construction of the wall. It is also important for the contractor to ask questions if confusion arises and to construct the walls exactly like the details. The Brick Industry Association Tech Notes provided information on construction practices to assure water resistant walls. The mortar plays a big role in preventing water penetration. Improper mortar joints can lead to leaks and loss of wall capacity. The mortar should be spread evenly and excess mortar should be cut off. If there is not an adequate amount of mortar there can be small openings that lead water into the building. During construction there is always going to be problems that arise. Sometimes flashing can tear or get pierced and it is important for the contractor to notice the problem and fix it before the exterior façade is complete. The flashing should be replaced or repaired with sealant and weeps should always be present above the flashing. If the design professionals and contractors communicate and everything is built according to the construction documents, water should not leak into the building causing problems. However, it is rare that buildings are constructed how they should be.

  12. Geoffrey T.
    September 13, 2017 at 4:34 pm #

    Based on the talk by Emily Wychock from SGH on 9/12/2017, we understand that there are 3 major wall systems. They are mass barrier wall, surface sealed barrier wall, and cavity wall system. The mass barrier wall is the system where the wall acts as both load bearing and water barrier to the building. It keeps the water out of the building solely due to the mass of the wall. The surface sealed barrier wall is the system where the wall is sealed at the exterior face, preventing water intrusion into the building. Both mass barrier wall and surface sealed barrier wall do not have any redundancy built into the system, meaning, if there are any cracks in the system, water can get into the building interior easily. These two systems are rarely preferred in the building industries due to the lack of secondary measures if water does get pass the first barrier. The most common wall system that they use nowadays is cavity wall system. In the cavity wall system, the water is allowed to drain through the cavity by the means of flashing.

    Even though the concept of cavity wall system is great, there are some flaws in this system. Construction details and workmanships become really crucial to make sure that the cavity wall system works well. From Emily’s presentation, we could see that the common problems that prevent this wall system to perform were the application of the water-resistive barrier and flashing installation. In one of her videos, it showed that the improper application of water-resistive barrier onto the exterior sheathing still allowed water intrusion into the building.

    Another problem that Emily mentioned in class was the poor workmanship in flashing installation. The purpose of flashing is to direct the water that manages to get into the wall cavity out to the exterior. In order to do this, flashing needs to be extended out to the wall exterior. Unfortunately, some of her photos showed that the flashings did not extend out to the exterior, preventing water to fully drained out to the wall exterior.

    Thus, even though wall cavity system may be the best possible system that we have, for now, workmanships and drawing details are very crucial for this wall system to work.

    One of the possible solutions that I think might work is to monitor the QA/QC procedure. However, it is impossible to monitor every single construction activities. So, for those who have experiences in QA/QC, is there any way that we can streamline the process so that we can avoid this problem in the future?

    • mkev
      September 15, 2017 at 6:01 pm #

      Geoffrey,
      The flashing not extending out the edge of the wall is not just an execution issue. There have been a number of documented cases where the architect visually did not want to see the flashing on the facade or have the shadow line so they intentionally showed it to be cut short. Another example of education or knowledge distribution is the key to prevention.

  13. Pete Pitilis Jr.
    September 13, 2017 at 4:06 pm #

    It was interesting to hear Ms. Wychock discuss the primary wall systems and their many modes of failure, especially in newer buildings. More often than not it seemed the failure was due to the improper construction of the building. For example, improper installation of vapor barriers, flashing, etc. I couldn’t help but wonder how these mistakes could have happened, I’ve always been under the assumption that there is quality control on a project and with that comes inspections. In some cases, it seemed that the person installing the product had no knowledge of how it’s supposed to function. So what is the main cause for these reoccurring mistakes and why are they not caught during construction, is it due to lack of knowledge, quality control, poor detailing, etc?

    • Nick S.
      September 13, 2017 at 5:53 pm #

      Pete,

      To respond to you question, I think it is hard to narrow down these reoccurring mistakes to one single issue. To me, I believe it is a combination of mistakes that eventually lead to the system failing. I know from experience that not every project can afford a full time QA/QC individual. This makes it extremely challenging to constantly monitor and enforce the proper installation methods. Poor detail is another common cause of creating issues in the building envelope and like we heard from Ms. Wychock, when there are not proper details it is up to the contractor to come to a conclusion. Leaving these details up to the contractor can lead to shortcuts and incorrect installation methods to help reduce cost and speed up the process(shorten schedule). Additionally, the lack of knowledge is another common pitfall because when contractors are not properly trained to install a system(flashing, vapor membrane, etc.) mistakes happen, creating issue that could be seen right away or down the road. One way that can combat all of these areas could be through the use of a building envelope mockup. Almost all project construct one of these and should be done for areas where the most difficult interactions between products occur. By building a mock-up each trade involved in the envelope can interact with one another and iron out all issue before being constructed in the field. To me this is the best way to ensure proper installation of the building envelope.

    • Tyler J
      September 13, 2017 at 8:16 pm #

      Pete,

      I believe the reason for these mistakes is a combination of the causes you mentioned above. However, I am inclined to think that most do not understand the impact that a small tear or hole can have in a barrier. Because many water proofing systems are redundant and overlap each other significantly, a small hole or tear may not seem like a major problem. In some cases, it may not be. However, a couple small holes can add up and become larger to a point where suddenly water is coming into a building and there is a major problem.

      To combat this, the industry as a whole needs to become better educated on this topic. Emily’s presentation just scratched the surface of water barrier walls but was a great step to help us as future engineers understand more about these systems and their importance.

  14. Megan F.
    September 13, 2017 at 4:05 pm #

    Emily Wychock’s presentation was very informative and engaging. Water infiltration is one of the biggest problems with building enclosures. The key is to never allow the water into the building, but other systems that Emily discussed actually let water in and provide a path for the water to escape; as long as the wall was constructed properly. Improper flashing is common when finding leaks in buildings. The flashing needs to be continuous over the surface of the wall and needs to be brought all the way to outside of the cladding. If the flashing is not applied that way, water can get into the façade and into the building and cause major damage. This is why sequencing is important when constructing the building façade. Every surface needs to lap over the next to create a continuous barrier that leads out of the building. For mass masonry walls, there is no flashing applied to the façade. The masonry walls act as the structural support and also act as the water barrier. Most mass masonry walls are thick enough that water wont absorb to the inside surface but some walls may not be thick enough and water will not stop entering the building. The mortar between the joints of the units has to be constantly maintained because these joints are the most susceptible to leakage. If the façade of the building is not constantly maintained water will leak in until it causes visual damage. Emily mentioned that the source of major water infiltration problems can end up being a small leak that continues to let water in and spreads across the façade.

    • cstefani
      September 19, 2017 at 9:49 am #

      I agree that sequencing during construction is extremely important when correctly installing waterproofing systems. The waterproofing system requires both a proper substrate, but has to be finished in time to allow for the exterior cladding to be installed. The biggest issues is when waterproofing membranes are installed wrong the first time, because typically the masonry or window installers are directly behind them. If the issues in the waterproofing are not identified and corrected in a short time frame, sometimes two or three days to a week, then it will be covered up forever. Or at least until an issue is discovered through damage of interior finishes, and costly investigating, demo, and re installation is required. It takes a large amount of QC and on site observation to properly evaluate the correct installation of the system, which is sometimes not feasible.

  15. mkev
    September 13, 2017 at 11:54 am #

    Nick,
    I will add that it can happen anywhere. We will see some examples of the same kinds of issues Ms. Wychock mentioned on our next “Campus is our Lab” field trip / walk around.

  16. Nick S.
    September 13, 2017 at 11:39 am #

    On Tuesday, September 12th, the AE 537 Building Failures class had the pleasure to hear a presentation by Ms. Emily Wychock. Ms. Wychock is a 2013 Penn State graduate from the Architectural Engineering (AE) program. Currently, Ms. Wychock is working for Simpsom Gumpertz & Heger Inc. (SGH). Ms. Wychock gave a brief introduction on SGH and explained how they are a national engineering firm that designs, investigates, and rehabilitates structures, building enclosures, and materials. SGH is broken into two practice groups; SE and BT. Ms. Wychock works primarily in the BT or building enclosures group.

    The presentation was focused on discussing three (3) types of wall systems (mass masonry, barrier, & cavity), waterproofing, and water management. During the discussion, all three types of walls were analyzed by limitations and keys to success. The discussion was then wrapped up with a case study of a project where water infiltration was a problem throughout the building. Ms. Wychock went through how they performed their investigation, their findings, and how to correct these issues.

    This presentation was extremely informative on how properly enclosing a building will greatly affect its performance. Like we have learned in lectures, case studies, and readings, water infiltration is one of the top causes for building failures. Some of the reasons why building envelopes fail, as stated in “Exploring the Building Envelope” PDF by Keith Moore, is because of poor design, poor construction practices, lack of maintenance, lack of resources, improper maintenance, and lack of understanding. To me the poor design and construction practices should never be the issue. I make this statement because of the purpose of a building’s envelope mock-up. A mock-up is done on every project involving the envelope. This is where the more complicated details can be investigated and is a time that all the trades involved can bring there issues to the table. Technology has also become an increasingly important aspect to the building enveloped development because modeling every detail can show how the system interacts.

    Unfortunately, the building’s envelope is an area that I see continually being an issue now, and in the future. I say this based of what I have seen as a construction student and a current employee with a construction management firm.
    We too often see poor details in the drawings not properly showing flashing, air/vapor barrier, insulation, etc. and like Ms. Wychock stated, many of these detail are left up to the contractor to determine. This allows for corners to be cut to meet schedule and save money. Sadly, most of these incorrect installation go unnoticed until a failure occurs and by that point, you are now paying more to fix the issue than it would of cost to properly install it.

    Overall, it needs to be our responsibility as young engineers, to learn from the past mistakes and ensure that proper understanding, installation, and performance of the building’s envelope occurs or nothing will change.

    URL of PDF: http://c.ymcdn.com/sites/www.rfmaonline.com/resource/resmgr/resource_library/session_20_-_exploring_the_b.pdf

Leave a Reply