Ep 125 - Latest Research in Wood Construction

34 min 28 sec

In this episode we speak with Marjan Popovski, Lead Scientist at FP Innovations. Marjan has been a major driver of some of the major developments in research in recent years. As a result, the industry is moving forward based on the hard work of senior leaders like Marjan. In this episode, we speak about the most exciting research, codes and standards, and finally where things are moving. 


Timber Talks Series 6

Series six of WoodSolutions Timber Talks, provides the latest informative and entertaining information about the best design practices, latest innovations and interesting case studies and interviews with world leading experts in timber design, specification and construction.

Episode transcript

Adam Jones (00:03):

Well, thanks so much for coming on the podcast, Marjan. It's an honor and privilege to get to speak to you with the experience you've got and the background. So can you start by telling us a little bit about yourself, your background, and then also introduce us to FB Innovations and the history there?

Marjan Popovski (00:22):

Yes. Thank you, Adam. And thank you first of all for an invitation to participate in your podcast. It'll be a pleasure. My name is Dr. Marjan Popowski. I'm lead scientist at FP Innovations in the Building Systems Group. FP Innovations is a nonprofit, Canadian nonprofit research institute that specializes in creation of solutions in support of the Canadian forest sector and its global competitiveness. So it's a Canadian public private research partnership between federal government, provincial government in Canada territories, lots of industry members, primary manufacturing, secondary manufacturing, and other members. And we have approximately 400 employees and three main locations and laboratories in Montclair in Montreal where the headquarters is in Quebec City and also in Vancouver, bc. So we have approximately 400 employees and the research budget around $60 million a year. Particularly I work in the business in the building systems group that provides holistic research approach to timber buildings and we provide research in terms of structural performance, seismic performance, fire performance, acoustical performance and other durability and other aspects related to the wood buildings. We think that we have to find an optimal solution from all aspects. We can always find a solution that works structurally that might not be the best for fire, that might not be the best for acoustics. So you always have to have that holistic approach towards the developing a new building solutions.

Adam Jones (02:11):

Yeah, it's amazing introduction.

Marjan Popovski (02:15):

Thank you. Just to say, I'm also a young professor at the University of British Columbia Department of Wood Science here in Vancouver and also in a program for integrated wood design at the University of Northern British Columbia in Prince George. So do lots of collaborative research with these two universities and also with many other universities in Canada and in the US as well.

Adam Jones (02:41):

Wonderful. And 400 researchers or 400 employees is an unbelievable team to actually get a lot of interesting work done. Can you outline some of the main research you've conducted over the years that you're most proud of and perhaps has been the most influential to help grow the market?

Marjan Popovski (03:02):

Yes, of course. I've been fortunate to be in the forefront of the research in the area of structural and seismic performance of timber buildings in Canada. And together with my colleagues at FP Innovations with Canadian wood Council colleagues and many colleagues from universities across Canada, we've done really tremendous amount of research work over the past two decades to improve and implement timber construction in the buildings, not only through research but also to code implementation. So I'm also quite involved in code implementation in Canada as well and I've served on some committees, so I'll go through some aspects that what I've done in the past, again with collaboration with many other and that will probably give the audience also kind of what has been done, what progress has been done in Canada over the years. So if I may start and go back to 2009, the limit for traditional wood frame construction at that point in British Columbia was maximum at four stories.


So in 2009 actually we were able based on FP innovations research and research from some universities with help with Canadian wood council, we were able to raise the limit from four stories to six stories for wood frame construction in British Columbia. Then we do the same with other provinces with Quebec, Ontario and so forth. And finally in 2015 we implemented the height change from four to six stories in the entire country and that was in 2015 National Building Code of Canada and that had significant ramification. Basically, since those code changes have been put in place, the market for wood frame construction really skyrocketed. So up to six stories now we have, I would say approximately 80 to 85% of the market share in addition to over 90% or 95% depends on the areas in North America where we have in the single family market. So we've done tremendous amount of work there to basically do something good for the industry for our members for innovations, but also for the society at large.


Then we also brought CLT to North America and we put our efforts into doing lots of research related to mass timber construction. So we implemented in 2016 supplement to the 2014 CSE six, which is the Canadian standard for engineering designing wood. This is where we implemented all our research and findings from how CLT performs and everything. And I'm proud to say that Canada, the first country actually that have those design provisions for cross-laminated timber, not only as a product but also as a system in our standard, as we all know, CLT of course was developed in Europe and Europe, but we actually were faster than Europeans to codify it. So I'm really proud of that I have to say. So that was a lot of work. You have to have lots of research, lots of information, and again, it was a multidisciplinary approach as well because we have to implement five performance of CLT and other aspects into the code.


So it was a really a large group effort on our side of innovations, Canada Wood Council and many other universities to actually do this work. And also I've been involved in work of many committees. I'm member of the technical committee of the CSO 86, which is again the engineering design in wood in Canada. I've served on the Canadian Committee for Earthquake design for one term, and I also sit on some international ISOT 65 committees as well. So I'm well aware and fighting hard to implement as many solutions for timber in the codes because we look at the codes in some aspects like barriers to timber construction and so forth. And also we've published a lots of handbooks throughout the years, starting with the 2011 with the first CLT handbook at Ation CLT Handbook, Canadian Edition. Then we had a US edition after that. Then the second edition of the handbook was released in 2019.


We put lots of effort into creating a technical guide for design and construction of tollwood buildings with the first edition and the second edition now released in 2022. And with the lead from my colleague, Dr. Zung Chen, he led the work on the developing the modeling guide, which was really an area that we need lots of information, especially for the designers and we did that as well. So I also participate on lots of international committees. As I mentioned, I'm part of the Canada Japan US Building Experts Committee, and currently we have in Canada, we just formed a new Canadian Wood Construction Research network, which is actually a network of 13 Canadian universities, includes FP innovations as well. And there are four teams in that network team, one which I'm co-leading with Dr. Tony Yang from UBC is related to structural and seismic performance of timber buildings. So there's lots of things going on in Canada was, as I said, again, I was fortunate to be part of all of these developments and be on the forefront of implementation of mass timber and wood frame construction in North America.

Adam Jones (09:26):

And there's no doubt it's had reverberations, the hard work from your team at FP Innovations globally for those who want to read your guides. It's not just reading a 20 page little brief summary guide. It's a 1000 page dent document backed up by all the best research and it really moves the needle. One of the things on code changes, which I find interesting. So Australia's gone through the same page and you mentioned there you've got 80% market share of, or 80 plus percent I think you said on I believe light frame construction for 4, 5, 6 stories. So correct me if I'm wrong on any of that, but what was it before the code change and how influential was the code change in actually developing new market share for that sector and what was the building types before? Because where we are in Australia and for those in New Zealand, it might be basically there might be a step change on the table following the model that you did as well.

Marjan Popovski (10:28):

I mean, as you know, first of all, Canada is a big country, I mean same as Australia. So really the market acceptance varies across the country. And again, the numbers change year to year, so don't get me a hundred percent on the percentage rate of, but definitely the five and six story market was basically mostly concrete before introduction of the six story limit for wood frame construction. We had the market up to four stories, absolutely. But then since the code changed, we made to six stories, we were basically over a period of six to seven years we started to own that market. And it comes also to a cost because wood frame construction tend to be a bit cheaper than concrete construction that was most eminent prior to that. So that plays a role as well, but you have to have the code if you don't have the code procedures, if it is not a code approved solution, and of course designers will not be able to implement it, you have to go through another procedure as we say, alternative solution path, which adds to the cost of the solution. So having it codified, it really made significant impact. Again, market share can differ from province to province, but on average, I think in Canada we are around 80% if not more right now in British Columbia, probably over 90%.

Adam Jones (11:59):

Wow. Yeah, that's so impressive. We've got 3, 4, 5, 6 stories or all concrete buildings and even though everyone sort of knows it's more cost effective for light frame, but it just hasn't, the ducks haven't aligned to actually just make changes there, which I find really interesting and inspirational from your market, which we can take on here, what are some of the misperceptions about timber that probably still persist and perhaps don't necessarily need to persist based on recent research?

Marjan Popovski (12:34):

Yeah, well exactly as you mentioned, there's some misconception and some are facts, but some are actually taken out of that context. Even. I mean wood burns, yes, of course wood burns, right? Wood rods, wood is not strong enough, the three little pig story. So the wood structure is not strong enough as a stoner or if you reflect to these days, rain force, concrete construction and so forth. So some of these things we try to really put research behind it and really make sense to what really means it's true that wood burns, right? But if you look at the other materials as well, continuous exposure to higher temperature and to fire affects other building materials as well. I don't think many people know that, for example, steel structures, they at 600 degrees sales seals, they lose half of the strength, half of the yield strength of steel. So the same with concrete, approximately same percentage. You have sping of the concrete in terms of rainforest concrete elements and reduction of strength. And I mention this all the time, it's a famous picture after the 1906 earthquake in San Francisco, there was a fire after the earthquake and actually there is a big heavy timber beam sitting still in a structure and a steel beam on the top of it almost melted like a spaghetti.


After the fire, the wood member was still supporting the steel beam who was like a spaghetti over it. So that just tells you yes, wood burns. However, if you use it in a right way, if you protect it, and especially these days, of course you do encapsulation, you use other protective devices, you use sprinklers and so forth, you can overcome all of these deficiencies with the rods. Of course if you're left in the rain for years. However, we have experiences that it's not that the case, for example, the state churches in Norway that are over 800 years old, built around 1200 ad, I mean I visited some of them, they're still standing. They're in perfect condition. So if you design, do proper design, if you keep the water out and not let it in and avoid this wetting and drying cycles in the wood, you'll do fine over years.


And if you're completely underwater, you also do fine. That's why we have all of these piers in the ocean so underwater, I mean a tree can stay for thousands of years. So some of it are mixed conceptions. Some of it are related to big fires that we had in the cities in the history, big London fire, big Boston fire, every big city where you have there've been fires at the end of 18 hundreds, early 19 hundreds. And that was kind of where prior to that, of course there was lots of wood construction. Those fires kind of put a stop to use of timber in the quantities that it was used before. And this is where basically when the steel and concrete took over a structural material, and since then it's been in the code, that distinction which we don't like, combustible and non-combustible construction, and this is basically how it happened after those big fires, people said, okay, still doesn't burn concrete doesn't burn.


Let's build with non-combustible construction. So other misconception is would structure have poor seismic performance? I mean, nothing can be further from the truth. I mean if you go to Japan, you'll see these pagodas and temples like Hogie temple that I've seen myself, it's been built 670 ad, so it's over 1,300 years old and it has been over 46 magnitude, seven earthquakes or higher throughout its life, and it's still standing there. So in another way it tells you that it's properly designed. Wood is a light material, and you don't have to be earthquake expert, you just have to know the second Newton law forces must times acceleration. So if a same building as from wood and from concrete, the rainforest, concrete or steel, it's applied same acceleration, just the mass difference will give you a much lighter force that the wood structures need to basically be designed for and absorbed during an earthquake.


And structures being lighter, of course you need less foundation and other things. So there's lots of misconceptions. But we are trying, and I think if I can use the word, the truth is out that some of these misconceptions were not true. I mean, of course wood burns, but have you ever tried to light a campfire using a big heavy timber member? No. So there is something to mass timber that really inhibits fire itself, so the showering that occurs and everything. So I'm glad that over the years and supported with research data, we were able to change these misconceptions.

Adam Jones (18:01):

Yeah, that's amazing and very well articulated on all of them. That's I think listeners when they try and talk through projects. So you can always borrow phrases in the way things are articulated, which is really helpful. So that's some of the misconceptions. There's also upside potential from the things we sort of know about, but we can get research to back it up. So sustainability and biophilia, all that sort of stuff. So is there any more research on that side, even forestry embodied carbon or anything like that to actually prove the benefits?

Marjan Popovski (18:39):

Well, for biophilia it's a very interesting effect. I'm glad that you're aware of that actually. And there's some research being done, although lots of more research has to be done. But the Japanese started that I think in 2005, there were a couple of Japanese studies that they tested the effect of the environment where you live in on your physiological health. So they made a conclusion that if you are surrounded by wood, either in a school setting or in a home setting or in an office setting, you have some health benefit, your blood pressure goes down, your heart rate goes down, you feel less depressed. Even in today's hectic lifestyle. And also in Austria, some research was done about that with similar conclusions. We've done research in Canada at FP Innovations as well about seven, eight years ago with a similar conclusion. So there's something about it.


There's definitely a trend. However, I cannot say a hundred percent that wood will make you feel better. I think still more research is needed. But even those three studies that I've mentioned, I think they're significant. And there's a significant difference between the health of the subjects that were studied in all of these studies is being either living or be present in a wood construction or being present in a concrete or steel construction. So there's that biophilia effect that you're right about it, it exists. So however, as I say, probably more research is needed in that area. And we are humans. We are part of this planet. That's how I look at it. We want to be in the forest. Why do we feel good when we go for a walk in the forest and breathe the fresh air? And we want to be part of nature and wood is a nature of material. So we feel at ease when we are surrounded by natural material.

Adam Jones (20:44):

That's amazing. And sometimes it's, sometimes it's just common sense almost. It's like as you said there, just you walk through, the research will catch up, but we can just use our own judgment and what makes you feel good being in a dog box in a concrete jail cell or in out in nature. Exactly.

Marjan Popovski (21:05):

That's what I do after a stressful work. I'm blessed to live at UBC and lots of forest around the area, lots of parks, and just going for a walk and having the fresh air, it really calms you down and gets you ready for the next days.


And of course the lower carbon footprint and everybody, all of these things and speed of construction. So there's lots of advantages to wood, especially mass timber. Lately prefabrication things can be prefabricated in a factory, ships on a site and so forth. So speed of construction time is money. So speed of construction can be, for example, for the Commons 18 story building here at UBC in Vancouver, they were able to build it in 70 days. So that's four months shorter than it would've been from other construction material. So that's a lot of saving on the behalf of the owner of the building. So it can make the building make use of the building much sooner. So there are lots of positive aspects. Of course.

Adam Jones (22:13):

It's unbelievable that building. We had Carla Fraser on talking about that one a couple of years ago, and it's crazy the speed of construction achieved there. So we've spoken a bit about research and code so far. What are the next updates to the code that you're actually trying to strive for Marjan? What are the discussions you're having in those meetings at the moment to push things forward?

Marjan Popovski (22:41):

Yes. What I have to say also is that we made significant changes also to the 2020 national Building Code of Canada that came just a couple of years ago. So we basically implemented mass timber as a structural product in construction and mass timber in Canada now can be used up to 12 stories in height in buildings. However, it has to be encapsulated because we kind of created a new product called Encapsulated Mass Timber Construction, which is basically a mass timber product with either gypsum, wallboard or concrete on both sides. So encapsulated for fire performance and using encapsulated mass timber, it can be, we can build a building up to 12 stories in Canada. So that's for the gravity loads for the lateral loads. We also introduced CLT as a system for sheer walls, and that one can be also used in low and moderate seismic zones in Canada up to 10 stories or 30 meters, but in high seismic zones up to six stories such as Vancouver.


So that was a huge change to put, and I was leading that word actually to put the CLT as a seismic force resistant system in the table of the systems that are in the code with seismic design coefficients. And that was a huge thing that we did. It was a first timber system in Canada that was implemented in the code after 30 years. So I just wanted to mention those two things that we are really important, and they just happened recently, 2020 and BCC came out I think 2022, early 2022 because of Covid, it was delayed a little bit. So what we are working right now is we are working to expand the market as well in the US as probably you are aware, they had the limits up to 18 stories. So we are trying on the fire side to go up to 18 stories and also working with some solutions on the structural side to go there as well.


We are working on to codify brace timber frames as a structural system because they'll use a lot in Europe, especially for wind design and seismic design as a good system. So we are trying to develop design guidelines to be implemented in the CST six, the Canadian standard for engineering design. And we are just starting to work on different types of shear walls, what we call balloon walls. The system that we implemented is the one the originally right from Europe. So you have basically one story wall, and then you have the floor and then the wall and the floor, what we call a platform type construction. Now we're going to try a balloon type construction, which is the wall going all the way from the bottom to the top of the building, and then the floors are attached to it on a separate levels. So that balloon construction requires definitely less cutting of the CLT, less manufacturing, but then it requires bigger connection at the bottom of the wall because all the forces from the building are transferred at the bottom for the lateral loads.


So we see those walls is a next field. And that's what we are basically working on right now, again, in collaboration with Canadian Boot Council in collaboration with other universities as well. And research in this area is also part of the network. So there's a lot of research that we are doing at the moment, but it's also a lot of research that has to be done in the future. So moment existing frames is another system. So the more systems we have, again, it took concrete and steel over 120 years to develop all of that research knowledge and to have solutions and guidelines and design guidelines for all of these different systems that they have. It's a lot of work ahead of us, but I think we are making significant progress.

Adam Jones (27:04):

Absolutely. I mean, I feel like step one is to build some sort of research and then design guides, and then the final big one is to get it into codes, which it takes a long time. So for you to actually get things done, change in codes code, there's huge stakeholder management, there's a lot of people you, I'm sure there's a lot of processes you have to get through and getting that code change is a massive, massive step.

Marjan Popovski (27:31):

And that's why we actually published all of these technical guides that I mentioned, some of them, and you are of course aware of them. This is to help the designers because as you mentioned, the code change takes years. It's a five year cycle, and then you need at least five years research prior to that to implement that new system. So in the meantime, the designers can use the alternative design solution in the code, which means they have to prove the performance of the new system or the new solution, whatever it is from fire structural performance, that it has the same properties as the accepted solution in the code. And then they have to satisfy the authorities have jurisdiction and fire marshals and everything as you said it. It's a really long process and that's why we produce those guides to help engineers until the solutions are codified so that they have research information, they have the technical information to go for the alternative solutions.


And I have to mention here, the governments have been also helpful in Canada, the federal government and provisional governments as well, into helping designers, having lots of programs where the designers can get some funding to do research and to implement solutions for tollwood buildings or non-residential applications where wood is lacking right now. So the next big effort I think should be non residential applications, bridges and so forth. The market is huge just for bridges. The other day a number came to me only in British Columbia. We have, I don't know, thousands of forestry road bridges that are ready to be replaced. So there's lots of work in that area. We have to come a solution with the larger spans and so forth. So there's lots of research route ahead of us, maybe not that much for me, but ahead of younger generations as well.

Adam Jones (29:29):

Yeah. Well, it's an exciting time. So where do you see things heading in the next five to 10 years with all the things we mentioned? If you had a crystal ball, where would you say, what does things look like?

Marjan Popovski (29:40):

I would see greater acceptance in timber, in the total construction and also in non-residential applications. What I would like to say also is I think the codes are moving into performance base design with performance-based design objectives behind them probably is the same everywhere in Canada right now we have objective-based codes, and I just want to take this opportunity to explain to the audience, so objective main codes, that means it gives you two options, the acceptable solution and alternative solution. So both of the solution, one is the prescribed one, like you get a flour and you put so much grams of salt and you put water and you mix it and you bake it, and it's called bread. And that's the only way how to make bread. But then if you do your own recipe on a side, you spend some research and your mind and some innovative things and you bake it and you taste like bread, then it's probably bread.


So that's the alternative solution. You don't have to follow the recipe, but you come up with the same product at the end that satisfies the safety of the occupants and all the objectives in the code. Then that alternative solution can be approved by the authorities having jurisdiction. So what the codes are moving now into the next phase, which is performance-based design. And that will tremendously help timber, I think it'll put it on an evil level playing field with other materials, which means there'll be non-combustible and combustible materials. It'll be just performance. I really don't care if this is a three hour performance, fire rating needed. I really wouldn't care if it is a steel concrete or the wood solution that provides the three hour fire rating. So same for the structural performance. If there are certain structural and seismic performance or floor vibration performance or acoustic performance, I really don't care what my walls are made of as soon as I meet that acoustic or floor vibration performance.


And I think that will put all construction materials at the same plane level field so that we provide the same performance for the owners of the buildings. And I think that I see where the codes are going. So then again, there's lots of research needed to support that code development and when that code development is in place to do research to provide solutions, which will be innovative solution to basically make that performance and have that performance option. So there's a lot of changes coming in front of us, but I think the glory days for timber are still ahead of us, that that's my gut feeling. Definitely more work is needed in, as I mentioned in, we talked a lot about residential construction, but non residential construction is an item that we have lots of work to. And even in residential, everybody wants larger open areas right now. So structural solutions that can support longer spans, like nine by nine meter, eight by eight, nine by nine meter is very difficult now to do with that with wood and in both directions. So we have to find a way how to do that. What would you say spanning of the, there's lots of research in Canada going on as well at this point on flood plate, CLT, basically CLT floors put on a column similar like rainforest concrete. So there's research going on on that led by Fasten app. It's a local design company in collaboration with University of Prince George. So there's work on diaphragms is needed and it's going on as we speak, as well. As I mentioned, balloon walls, different types of walls. So there are lots of aspects that we have to basically still work on.

Adam Jones (33:44):

Yeah, well, it's a really exciting future. What's coming ahead, if people want to find out more about yourself, Marjan and the research done at FP Innovations, which is a whole lot of where should people go?

Marjan Popovski (33:57):

I think from FP Innovations perspective, just to visit our webpage, WebP innovations.ca and you can go to free download some of the guides that we've produced or they can contact me directly via email, Marjan dot popovski@fpinnovations.ca. I usually respond to every email I get, so I just feel free to contact me if you need anything.


And if I cannot Help, I can definitely refer to somebody else who has the knowledge for that topic.

Adam Jones (34:32):

Amazing. And for those Australians listening, it's spelled M-A-R-J-A-N because I know how much we Australia, we're probably the worst at pronouncing the different forms of J around the world.

Marjan Popovski (34:43):

Having a J in a name in English, word is terrible. So Marjan Popovski, M-A-R-J-A-N, dot P-O-P-O-V-S-K-I at FP innovation dot com.

Adam Jones (34:53):

Well, it's been absolutely amazing to get to chat to you. It's a privilege. So thank you so much Marjan, and that was amazing and we'll leave it there.

Marjan Popovski (35:01):

Thank you, Adam. Thank you again for the invitation and to be part of your podcast.

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