< PreviousBuilding Science Specialist Board 2800-14th Ave., Suite 210 Markham, ON L3R 0E4 Tel: 416-491-2886 www.BSSB.ca Are you knowledgeable enough to become a Building Science Specialist? Do you think that you are knowledgeable enough to obtain the BSS destination? 90% of exam applicants got these questions wrong: • Briey explain the function of a “Stack Joint”. • Briey explain why the exterior of a below- grade cast-in-place concrete foundation wall is often covered with bituminous coating. • Suggest a chemical admixture which would be logical to consider for an industrial oor slab (which will be enclosed inside a build- ing) being placed outdoors in July. Explain the purpose of the admixture and justify why it would likely be required in this particular application. The BSS Designation is not a license to practice Building Science, it is a certication of a level of knowledge that those who obtain the designation are highly skilled in the practice of Building Science. The BSS® (Building Science Specialist) designation provides members of the industry, including building designers, speciers, developers, contractors, and owners, with the condence that any designation holder has a high level of education and understanding in the eld of Building Science. These individuals have written and passed an extensive set of exams covering: • Building Science Theory Exam • Building Envelope Systems Exam • Materials Exam • Mechanical Systems Exam In addition to obtaining a minimum 65% in each of the above four exams, the candidates must also have an engineering or architectural undergraduate or graduate degree and at least 2000 hours of practical experience directly related to the practice of building science. OR Have an engineering or architectural diploma from a recognized college or polytechnical institute and at least 5000 hours of practical experience directly related to the practice of building science. On our website at https://bssb.ca/bss-exam/learning-objectives the BSSB provides a list of detailed learning objectives and reference material listing everything you need to know to self-study for the exams. The exams are closed book. It is the candidate’s responsibility to ensure they are prepared to write each exam after reviewing the current Learning Objectives posted on this website. We also provide a comprehensive list of courses that may help you prepare for the exams, but these are provided for reference only. They can be found on our website at https://bssb.ca/bss-exam/exam-courses. Many of these courses are part of a degree or certicate program only so you must contact the relevant institution to determine whether you are eligible to take the course. Note that the BSSB does not endorse any of these courses and does not certify that the content covered by the courses is the same as what is covered on the exam. Do you have what it takes? Visit: www.bssb.ca Pushing the Envelope Canada 11 Building Envelope Systems Exam DATE: JUNE 26, 2020 TIME: 1:00 P.M. – 4:00 P.M. LOCATION: TO BE CONFIRMED. CHECK WWW.BSSB.CA FOR CURRENT DETAILS. Materials Exam & Mechanical Systems Exam DATE: OCTOBER 16, 2020 TIME: 1:00 P.M. – 5:00 P.M. LOCATION: TO BE CONFIRMED. CHECK WWW.BSSB.CA FOR CURRENT DETAILS. Building Science Specialist Exam Dates n n n UP FRONT . Pushing the Envelope Canada 13 A French Chateau’s cellar is the traditional place to store wine, as it remains at the accepted 55 o F naturally. I love wine. People think I must know something about the stuff because I drink a lot of it. I don’t really know much, but I do know what I like: red, French, and with a cork. Most of the questions I get, I have no clue about, so I make up stuff—I am a consultant, after all. But I know how to store the stuff. Here is the magic formula for storing wine: 55 o F at 70 per cent relative humidity. Where does that come from? Old French guys. 1 That is not the temperature you should drink it at but the temperature and relative humidity you should store bottles at. Drink- ing temperatures are more difficult to pin down. There is no consensus; it varies by type of wine and which nation produces it. 2 The colder you store wine, the longer it will last. So why not store it colder? We want it to age, which means we want chemical reac- tions to continue in the bottle for a long time. If it is too cold, these reactions don’t happen. There is a difference between “preserving” wine and “aging” wine. How did the French pick 55 o F? Tradition, mostly. Wine was stored in cellars—that is why we call them wine cellars. If you have a n n n FEATURE Blending Vintage Wine with Building Science: Reserve These Tannin-Techniques to Ensure Your Cellar’s Body Has Legs By Joe Lstiburek, B.A.Sc., M.Eng., Ph.D., P.Eng., ASHRAE Fellow, Building Science Corporation A professional at work in the wine cellar. Barrels need higher humidity conditions than bottles.14 Spring 2020 • Ontario Building Envelope Council big, old-fashioned French Chateau handy, you will find the temperature in the cellar at about 55 o F. What about relative humidity? Notice, earlier I said “bottles.” Most wine in the Chateaus starts out in barrels. Drinking out of the barrel is complicated—you can’t move them easily to the dining room so you need a guy with a “thingy” (yes, that’s the technic- al term) that extracts wine directly from the barrel into a waiting glass. The French, the innovators they are, figured bottles made from glass—small enough to carry—would be more convenient. Why not put wine into glass bottles straightaway? Not so fast. The barrels are made of wood, and the wine needs the wood to be able to taste like wine (read: good wine). 3 The type of wood the barrel is made of is a big deal. Oak is optimum. French oak is magnifique for French wine, American oak is ideal for American wine, Slovenian oak is preferable for Italian wine, etc. The barrels themselves are not imperme- able. Wood is not a vapour barrier, nor an alcohol barrier, nor an oxygen barrier. Water diffuses out, as does alcohol, while oxygen diffuses in this outward diffusion of water, and alcohol concentrates the flavours, whereas the diffusion inward of the oxygen governs the chemical reactions. For the wine-making process, it’s im- portant the vapour diffusion outward is con- trolled—slowed down, but not stopped. This is done by storing the barrels at a high rela- tive humidity. How high? Back to the French, again. A cellar in France has about 80 to 90 per cent relative humidity. You’re not going to find those conditions in a cellar in California unless you get help from an ASHRAE member. Even with help from an ASHRAE member, you’re not going to get conditions identical to France. You’ll get close, but it will not be the same. You’re going to get California conditions. Therefore, you’re going to get wine that taste differently. Now, let’s think about the consequences of temperature and relative humidity condi- tions relating to 55 o F and 80 to 90 per cent relative humidity. Great for making wine and storing wine barrels—not so great for the space. Without fail, you’ll get all kinds of mould. Is this mould good or bad? The mould on the walls doesn’t seem to be a problem; it’s how the mould is cleaned that can be the problem. Cleaning with bleach leads to some- thing called 2,4,6-trichloranisole (TCA). If FEATURE n n n Figure 1: The typical indoor conditions in both summer and winter in North America. Vapour flow occurs into the wine cellar during the summer and out of the wine cellar during the winter. Figure 2: Bi-directional vapour flow through semi-vapour impermeable extruded polystyrene. Note the back ventilated interior lining and the absence of paper-based materials.Pushing the Envelope Canada 15 n n n FEATURE TCA gets into wine, it becomes tainted. The French don’t worry about the mould on the walls in their wine cellars that store barrels. They also never use chlorine in their wineries for cleaning purposes—simply soap, water, and elbow grease. They tend to build these cellars out of rocks and wood rather than paper-faced gypsum board and engineered lumber. It’s harder to get mould on rocks and wood than what we use in North America. In the U.S., particularly California, the zeal to eliminate mould with chlorine led to tens of millions of dollars’ worth of tainted wine. I love to watch the French in Califor- nia, especially near food or a winery—their heads would explode. 4 We also put chlorine in water. It’s not a good idea to have chlorin- ated water anywhere near a winery or a wine cellar. What the French do worry about is mould in corks. This becomes more of a problem once we take the wine out of barrels and store them in bottles. Too much humidity, and we get mouldy corks. Too little humid- ity, and we get dry ones. With a dry cork, air can get into the bottle, and that will lead to spoilage and potential evaporation. That’s why wine is stored horizontally, so the wine keeps the cork wet on one side, maintaining the seal. Why not get rid of the cork and use some- thing that seals better for longer? The only reason we used cork in the first place is be- cause it was the only technology available at the time. It’s like the designated hitter rule in baseball: there will never be peace between the American League and the National League. The folks who want to get rid of the cork are American League-types—why use poor technology (e.g., corks), and why watch a lousy hitter (e.g., pitchers)? The folks who want to retain the cork are National League- types—purists and traditionalists. If we have cork-in wine bottles and want to store the wine, what do we do? Back to the answer at the beginning of this story: 55 o F at 70 per cent relative humidity. The 70 per cent relative humidity is just about the maximum we can maintain without damaging corks. It’s also a good humidity to keep the cork from drying out. What’s the rate of moisture entry into the cork on the wine side versus the rate of evaporation on the outside-seal side? We have 100 per cent relative humidity on one side and 70 per cent on the other. Seems to work. How do we know? Watching lots of bottles for lots of years. What do 55 o F and 70 per cent relative humidity mean for wine cellars? Well, for the French and their Chateaus, it means they must install dehumidifiers in their cellars if they want to store their wine in bottles with corks and paper labels. If you don’t happen to be French and have a Chateau with a cellar and a dehumidi- fier, what do you do? You construct a wine cellar using a psychometric chart and some building science (see Figure 1 on page 14). To make this work, I need an assem- bly that handles bi-directional vapour flow. I prefer materials that are semi-vapour impermeable and more-or-less homogenous. That way, flow is slow in both directions, but isn’t eliminated in either direction. Figure 2 on page 14 provides a pretty easy way to construct a wine cellar if you don’t happen to have one. Cheers! n Joe Lstiburek, B.A.Sc., M.Eng., Ph.D., P.Eng., ASHRAE Fellow, is a principal of Building Science Corporation. He is a forensic engineer who is recognized as the authority on moisture-related building problems and indoor air quality. AUTHOR’S MUSINGS 1. Yes, I know other folks also make good wine. However, it is much like asking Canadians about hockey, even though other folks play pretty good hockey. They are the “experts.” 2. For example, ASHRAE legend Ollie Fanger carried around a gold therm- ometer with him wherever he went to ensure the wine he drank was at pre- cisely the correct temperature. 3. Some wine manufactures do this part of the process in large stainless-steel vessels they spike with wood chips. 4. Memo to the French: the rest of us also think the folks in California are crazy. The barrels are made of wood, and the wine needs the wood to be able to taste like wine (read: good wine). Pushing the Envelope Canada 17 T he journey in pursuing my own, hands- on approach to complete a deep energy retrofit began in 2014, when I purchased a 1904 semi-detached home in the east end of Toronto. My formal education is in civil engineering, but my real passion is build- ing science; so, what better way to learn than to get my hands dirty with my own self-build? Our first winter of 2014-2015 revealed the house’s major energy inefficiencies: the HVAC ducts were neither insulated nor air sealed, there was a large hole in the founda- tion wall for HVAC “fresh air,” and the walls were largely uninsulated—all aspects made the house perfect for a deep energy retrofit. PROJECT GOALS Like any high-performance build should aim to achieve, the goal was to improve the building’s durability, occupant comfort and health, and energy efficiencies. My goal was to improve the building with principals from the “pretty good house” movement. I fol- lowed the exterior insulation method outlined in the Mass Save Deep Energy Retrofit Builder Guide by Building Science Corp. (see Figure 1 on page 18) and the forum discussions at www.greenbuildingadvisor.com. I also worked through smart efficient details to better understand the high-per- formance systems and materials, building an architecturally aspiring green home (what’s the point of a high-performance house if it’s an ugly box destined for the landfill within a few decades?), and maximizing passive heat- ing and passive cooling systems. At the time, going off fossil fuels wasn't a goal; today, how- ever, it most certainly is. PERFORMANCE HIGHLIGHTS Super insulation was one of my main focus- es. An overview of the project’s thermal insula- tive performance is shown in Figure 2 on page 19 and is compared against code-built project and the original project prior to the deep energy retrofit. The figure also highlights how windows de-rate the effective R-value of walls, even with high-performance windows and a 20 per cent window-to-wall ratio. Continuous exterior insulation and batt insulation used within stud cavities helped achieve high performance. To provide an uninterrupted blanket of continuous insu- lation, the existing roof overhangs were cut off. Thereafter, new eave overhangs were in- stalled for good water control and to maintain architectural intent. New, high-performing windows were installed to maximize the over- all building performance. More on this, later. INSULATION SYSTEMS Four-inch-thick exterior insulation in two staggered lifts of expanded polystyrene (EPS) foam board and graphite-impregnated EPS (GPS) wrapped the exterior walls, and sev- en-inch-thick EPS and GPS insulation wrapped the warm roof. Pine strapping (one-by-three) on the walls and roof allowed the attachment of siding and roofing (see photo on page 19), and provided a vented rainscreen cavity. Long screws secured the strapping to the framing at the walls and roof. I chose EPS and GPS foam board insulations based on good insulative properties, lower costs, and lower global warm- ing blowing agent potential (see Figure 3 on page 19) and mineral wool batt insulation to fill walls and ceilings due to its excellent fireproof- ing, soundproofing, and insulating properties. Spray foam insulation was decided against based on its very high global warming blowing agent potential, toxicity, and flammability. There are also concerns with its long-term airtightness (one of its primary benefits). In considering other insulation materials, high material costs and proper airtightness also played a part. Do your research to find the best fit for your project. AIR BARRIER AND VAPOUR RETARDER The traditional poly vapour barrier was designed out to prevent the risks associated with a vapour sandwich caused by the vapour impermeable poly sheet on the interior and foil-faced EPS on the exterior. These two impermeable surfaces could trap moisture within the wall. If not allowed to dry, trapped By Grant Walkin, M.Sc., P.Eng., Building Envelope Specialist, Entuitive Corp. Lessons Learned from Self-Building a Super-Insulated House n n n FEATURE Pre-renovation: the 1904, semi-detached east Toronto house. Post-renovation: the 1904, semi-detached east Toronto house, modernized!18 Spring 2020 • Ontario Building Envelope Council retarder if installed correctly. I used red tuck tape to tape the foil-faced insulation, which was an effective, low-cost solution at the time. However, it was later found to de-bond indis- criminately on the roof and walls to the foil facer, so I replaced the tape with a high-qual- ity, acrylic adhesive tape with outstanding re- sults. I guess you get what you pay for. WINDOWS The windows were high-performance, triple glazed, double low-e coated, fiber- glass-framed windows. To deal with the thicker walls, factory installed interior jamb extensions were fitted to allow the windows to align with the exterior insulation plane, which maximizes thermal performance. The low-e coating and glazing surface were customized on each win- dow elevation to maximize solar heat gain in the winter and minimize it in the summer. MECHANICAL HEATING, VENTILATION, AND AIR CONDITIONING (HVAC) SYSTEMS High-performance heat recovery venti- lators (HRVs) are critical for high-per- formance, air-tight buildings. The HVAC systems, or as I call them, the comfort FEATURE n n n Figure 1: A thermal insulative performance comparison between my self-build, a standard code build, and pre-renovations. moisture could lead to building failure. Mois- ture could enter from the interior in the form of water vapour through an electrical recep- tacle or from liquid water penetration around a window. It’s a factor of when, not if there will be moisture penetration. The building’s vapour retarder was pro- vided by latex paint on drywall using the air- tight drywall approach, a method approved by the Ontario Building Code. Disclaimer: this method is incredibly tricky to do correctly and should only be completed by experienced pro- fessionals. A smart vapour retarder was used in the bathrooms. Although a robust design, an even more resilient design would have been to drop the foil facer on the exterior and pro- vide a smart vapour retarder on the interior behind a service cavity; out of harm's reach, from electrical, plumbing, and other service penetrations. At the building’s rear extension and over the roof structure, the air barrier was oriented strand board (OSB) sheathing with taped seams. Elsewhere, the air barrier (and water control layer), was provided by the foil-faced taped insulation seams. It’s best to provide the air barrier toward the building in- terior, which I did for the rear extension. The air barrier could also double as your vapour Pushing the Envelope Canada 19 systems, are comprised of a combined HRV and heat pump system. This spe- cialized, all-in-one unit provides fresh air with HEPA filtration, heating, cooling, and dehumidification, operating based on sensors of temperature and humidity. The unit, with a coefficient of performance (COP) of four, lives in the conditioned knee wall to optimize space. For future builds, I would prefer a standalone HRV and heat pump, as each system has its own job. These combined systems could be reserved for very small buildings, such as multi-unit residential buildings. A mid-efficiency (67 per cent) gas fire- place was selected for supplemental heat and n n n FEATURE Figure 2: Wall-to-roof interface detail; note the continuous control layers and the exterior insulation that wraps continuously from the roof to the wall. ambience. It provides a resilient heat source that operates without electricity during power outage and is sized to heat the entire house in winter, if needed. The fireplace incorporates a direct, co- axial vent to draw and preheat combustion air from the exterior. This provides three benefits: 1. Sustains an air-tight building assembly; 2. Maintains a pressure-equalized space, so not to draw in uncontrolled and uncondi- tioned exterior air; and 3. Improves efficiency. I installed a high efficiency (95 per cent) direct vent condensing tankless gas water heater. While these gas units are very efficient, there have been large leaps in electric-driven hot water technologies over the past decade. Heat pump water heaters have extremely high COP levels, with one manufacturer having a published COP of six! CLOSING While this build did not pursue any high-performance certifications, it certainly entailed a lot of high-performance systems and is leaps ahead of the standard code min- imum build. The hands-on experience taught me many lessons. For me, the project was a success, both in performance and architectur- al aesthetics. For others pursuing a high-per- formance project, the team’s experience and collaboration will be most critical for the suc- cess and cost of the build. n Grant Walkin, M.Sc., P.Eng., is a building enve- lope and structural glass engineer at Entuitive Corp. in Toronto. He specializes in commercial, institu- tional, and residential high-performance buildings.Figure 3. Comparing foam board insulations: EPS, XPS, GPS, and polyisocyanurate. Foil-faced insulation seams taped to provide a continuous water control layer, along with one- by-three wood strapping over-top and screwed to the structure. Two inches of foil-faced EPS insulation over five inches of GPS insulation with staggered seams over the roof structure were then installed.Next >