Is OSB an Air Barrier?

In a sharp exposé of the current use of OBS in high performance houses, GBA Editor Martin Holladay brings to light a number of important details on what is and what isn’t an air barrier by Canadian Standards. The OBC states in (1) [that an air barrier  has an] air leakage not greater than 0.02 liters/sec-m² measured at an air pressure differential of @75 Pa, which according to the article is based on the permeance of drywall.

In an earlier study published by Building Science Corp on permeance and sorbtion tests done to OBS samples by P. Christopher Timusk of George Brown College, that suggested the sample’s moisture content increased non-linearly as relative humidity increased. In a recent news letter form Building Science Corp, BSI-038, some cautionary notes were issued about the use of OSB in “Things get very risky if you use a high-density spray foam on the inside of OSB sheathing. There is no way that any appreciable moisture in the OSB can dry inwards. The only drying possible is outwards. We need the gap.”

If you use OSB as sheathing and plan on using it as your air barrier for a high performance project – caveat emptor! Click on the link above to learn more!


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Time to Redifine the ’100 Year Storm’?

The statistics on changing climate are stark; where a hundred year storm used to happen every hundred years, we’re now seeing 3 ‘hundred year storms’ take place every 25 years. Yet our building codes are based on, and assume a 100 year storm every 100 years. Our changing climate is pushing the boundary of acceptable building resiliency. With more localized and exaggerated storms, building resiliently should be a municipal and provincial priority with a national strategy in place.

Ontario Premier Kathleen Wynn recently emphasised that increasingly severe weather is putting pressure on aging infrastructure adding that “When infrastructure fails the costs are catastrophic,” she said. “Public infrastructure‎ in Canada has been neglected by all levels of government for too long,” Wynne told a special inter-provincial summit this past Wednesday. “And I would argue that now — time is up,” she said, adding progress can only be made when the provinces and the federal governments work together.

With Insurance companies washing their hands of coverage when “overland flooding” occurs, homeowners need to seriously assess and protect their interests when renovating or building new. “Building to Code” minimums won’t protect you and especially in a climate emergency or grid failure, having the resilience and self sufficiency to ride out a storm depends greatly on how successful your planning is now.


“These [once in] 50-year floods are occurring every 10 years, because our climate has changed,” said Environment Canada’s senior climatologist Dave Philips and adds that planning for weather based on the past 100 years “masks” recent events that have dramatically changed how much rain falls. He said in the aftermath of the Toronto floods of August 2013, a look into the last 25 years of rainfall showed that there were three 100-year storms, and six 50-year storms.How to buid


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Is Building Durability Linked to Love and Beauty?

Buildings last as long as we care for them and to do that, we have to love them. Can we maintain ugly buildings; yes, but its easier to mistreat an ugly building and give it short shrift. Humans are drawn to beauty, what else can be said?

And so it is, in 1962 a plaza was built on a large parcel of land just off Dundas St. West, south of Bloor Street in Toronto. After the Zellers closed a few years back, this nondescript parking lot was given a new lease on life with an LCBO opening a store. But for how long?



This plaza south of Bloor Street West at Roncesvalles and Dundas Streets won’t be around to fulfill the promise made below.

When I pick up groceries, I often walk across this beautiful, heavy brass plaque entombed in part of the sheltered walk way. It’s a time capsule, not to be opened till 2062. We’re not talking Ghiza, we’re talking a plaza that’s run down with a leaky roof over the vacant, flagship unit.


Will the time capsule have to be moved as the areas gets increasingly gentrified? Only 48 years left before we can open it, a bit more than halfway done its time.

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Window Testing for Air Leakage and Water Intrusion

As part of our envelope commissioning services, BGG is going to be offering window air leakage as well as rain water intrusion testing for installed windows and for the proactive; mock-up window testing. By 2016, the trusty CSA Standard A440-00 and the American AAMA/NWWDA 101/I.S.2-97 will be officially replaced with one North American Fenestration Standard, the AAMA/WDMA/CSA 101/I.S.2/A440-11, simply known as “NAFS”. The NAFS is used for testing and rating new windows, doors and skylights.

Joined by the esteemed gentlemen of ThermalWise based in Halifax NS,  Jordan MacDonald and Tom Kendell, we made our way to “The Cities” (colloquial for the proximal cities of Minneapolis and St. Paul), then by car west through deep freezing temperatures to Watertown, South Dakota. We were here for 5 days of intensive training on testing windows guided by Mike Sovell of Sovell Investigative Testing & Consulting.

Mike cut his teeth on the myriad standards that guide the testing and installation of windows with behemoth Architectural Testing and now runs his own shop testing all manner of windows and training people. Its not an easy task and Mike does a good job of prepping you for what one might expect in the field. We really appreciated Mike’s insights on the industry and he did a great job shedding light on the dozen or so standards that shepherd durable window selection, installation ASTM E2112-07 and field testing ASTM standards E1105-00, E783-02 and a few forensics standards for good measure. You get the picture, standards were waded through at a brisk pace.

We were treated well in South Dakota, stayed at a great place outside of town overlooking a small lake. Mike urged us to go out for prime rib in tiny Kranzburg – population 172, we’re going back for the 4th of July – at Jeffrey’s Super Club where the slabs of prime rib were the size of a goat’s head! It was the highlight of our trip food-wise.

I was happy that no one or nothing was defenestrated during our training and sadly, no one made any defenestration jokes; a great word that gets short shrift in the English language.

The Wind Maker Plus test kit looked like a robust testing apparatus for doing both air leakage and rain water intrusion testing.

The Wind Maker Plus test kit looked like a robust testing apparatus for doing both air leakage and rain water intrusion testing.

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Shervin prepares his window frame enclosure on the ‘conditioned’ side of the envelope.

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The German engineer inspecting the ASTM calibration apparatus for ensuring low air flow readings of testing equipment are within allowable specification of the standard.

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L-R: Trainer Mike Sovell takes Jordan MacDonald, Shervin Akhavi and Tom Kendell through 5 days of grueling training at his testing lab in Watertown, SD.

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Mike masking off the window to prepare for a ‘tare reading’ of window air leakage.

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Mike Sovell taking us through the paces on how to set up and use the testing equipment for air and rain water intrusion testing.

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Shervin having selectively masked his window to test for water intrusion through the window only. With the spray apparatus set up, he was ready to drop 8″ of rain per hour’s worth of water on that poor window.

SD House

This lovely century Arts and Crafts house was furnished to the nines, all original wood with such generously sized rooms. A lovely stay overlooking a small lake amidst farm country.

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The reading of ASTM, CSA, AAMA standards for 5 days on-end can have a depraving effect on its readers. Buffeted by copious amounts of good local and not so local German beers, we made it through the 5 day ordeal thanks to this powerful antidote. It had nothing to do with the fact that 2 east coasters and one German were part of the Canadian contingent.



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Xmas Comes Early to BGG

I came in this morning to find our work mail box stuffed with packages from Minneapolis!

We bought a Duct Blaster that will allow us to quantify air leakage in duct work. Further, if the duct work runs outside the building envelope (ie in cold attic or crawl space), we can now quantify how much air leakage these “exterior” ducts leak. This kind of data will serve anyone with attic duct work well when trying to decide if the duct work is responsible for ice damming or condensation generation in the attic. It will also be more portable than the Model 3 fan when doing High Performance houses or doing LEED ETS tests in highrise buildings.

We bought the True Flow meter too and now we can measure how much air flow the air handler is moving. This can help on the diagnostic front when matching AC size, it can also help us do air flow accounting of cumulative air flows to see what’s happening in those cold rooms!

We also got WiFi controls so that we can control out machines remotely and collect our test results directly on the computer. For specialised tests, we can control the fan and test remotely using Android or Apple platforms! So exciting!

We’re also ready for larger industrial, institutional or commercial depressurisations  air test with our new 3 fan in one man-door opening for the times when you need to move lots of air!

I also have an old fan that is in desperate need of new rings and they came in! Speaking of rings we have a “D” and “E” ring for those super tight rooms – though our duct blaster can also serve the purpose. If you’re house is the first to need a “D” ring, I’ll eat the cost of the test!

Here’s hoping Santa is as generous with you!

New rings for an old blower door! Plus a Duct Blaster and a TrueFlow meter! Thanks Santa!

New rings for an old blower door! Plus a Duct Blaster and a TrueFlow meter! Thanks Santa!






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Touring The Energy Conservatory in Minneapolis

We were recently in “The Cities,” as Minneapolis and proximal St.Paul are known locally, so we did what any self respecting building science buff does before heading to the pub; take a tour of The Energy Conservatory’s facility! Paul Morin, a guy we’ve been dealing with for nearly 15 years, gave us the tour.


TEC Logo

The link on the logo above brings you to TEC’s new web site – which is under construction – and the about section wasn’t up at the time of publishing.

Nestled in a light industrial area of Minneapolis, TEC shares a large building covered in solar panels with a coffee roaster and many other small businesses. The wafting smells of freshly roasted coffee along with the patented “new blower door smell” were enough to send us over the top! But Paul kept us focused and showed us the myriad cavernous rooms that included an office, a calibration room, a creative R&D space, shipping and receiving/storage room, training facility and a product assembly room.

We were particularly impressed with the R&D room. Having just come from training in South Dakota on fenestration water and air testing, we were particularly interested in measuring really low air flows precisely and as luck would have it, TEC were developing a product for the French market. Thanks for the tour Paul!

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L-R: Paul Morin gives a tour of the Minneapolis facility’s calibration lab to BGG’s Shervin Akhavi and Haligonians Jordan MacDonald and Tom Kendall of ThermalWise. Tom is holding the control fixed by Paul’s mere touch! It was a miracle to behold, we all witnessed it and perhaps one for the canonization of St. Paul Morin of Minneapolis…

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Wow, a picture where we’re together – thanks Jordan! Shervin and I checking out the R&D lab. This place would be my dream job; a creative lab where all manner of testing equipment is designed, prototyped and refined. In the background you can see a large fan used to produce steady air flows. Shervin recalls from his days at engineering school in Darmstadt using “Minneapolis” equipment, a brand widely revered throughout the EU.

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Theoretical Knowledge + Hands-On = Awesome!

In his latest blog entry, Heat Transfer When Cooking a Turkey, Martin Holladay muses on cooking the perfect turkey just in time for US Thanksgiving. If you take the time to read it, not only will you get some amazing tips on how to cook the big bird, but you’ll learn to appreciate why a blend of theoretical and hands on experience helps produce better results.

We at BGG feel the same; our nerdy computer energy modeling experience blended together with practical, hands-on experience gives us the edge over stuffy, overpriced engineering firms stuck behind a desk doing finite element analysis. Not only can we apply the Ponofsky equation, but we can cook too! Happy belated thanksgiving and do have a read on the link above!

Source: Wikipedia.

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Pitot meet Android

Using a Pitot tube to balance a typical residential HRV install is like making sausages; you don’t want to know what kind of assumptions went in to making that number and yes, as discussed in our previous blog, we at BGG are trying our best to produce more robust numbers than what this simple device invented in 1732 by Henri Pitot.

When in the field, sometimes life throws you lemons and all you can produce is  sausage! As unpleasant as using a Pitot tube in a confined space can be, I made a pleasant discovery the other day when I stumbled across Dwyer ‘s Android App (click on link below). This simple app with no baggage (and it’s free) takes the tediousness out of converting pressure in a multi-step calculation to determine air flow through a given diameter duct.

Thank you Dwyer!

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BGG published in Home Energy Magazine: ACIN Balometer Review

As you know, BGG has just invested in what the world-over sees as the pinnacle in air flow measuring tools; the ACIN Flow Finder Mk 2. As we dive headlong into the commissioning of ventilation systems, we felt there had to be a better way to measure air flow and with this tool we’re developing a more sophisticated process for not only balancing air flows in and out of the house but also adjust flows room by room so the intended design gets realized for optimal health and comfort.


“It is the mark of an instructed mind to rest satisfied

with the degree of precision which the nature of the subject permits

and not to seek exactness where only an approximation of the truth is possible.”



We were the first to review the device and publish the article in the venerable Home Energy Magazine’s November 2014 issue (see link below) and so far so good on the instrument front, but as Aristotle points out above, sometimes, extreme accuracy comes with extreme frustration as the accounting of precise air flows doesn’t add up. Needless to say, we’re leaving no stone unturned and using all manner of testing apparatus to measure air flows. Keep posted to find out if we crack this nut or if we throw our hands up and admit the nature of the subject only need the humble garbage bag test and a Pitot tube!


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CBC’s Anna Maria Tremonti Tackles Modern Architecture

Big thanks to Anna for getting the ball rolling on ‘Starchitects’ and the buildings they saddle society with. Guest architects Don Schmitt and Lloyd Alter suggest that good architecture fits in the community and the climate where the buildings get built in – something Starchitect like Gehry throw under the bus in favour of flare. Whereas guest Elsa Lam seems to think there’s more room for experimentation in architecture – clearly, she didn’t read Faulty Tower, Adele Weder’s stinging review for the Museum of Human Rights being built in Manitoba. All agreed that in 40 years or less, the high rises being built will have to be re-built (Lloyd suggests in 15 years) for either efficiency or because they aren’t beautiful.

Have a listen to this important piece on The Current.


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