Evidence of meeting #88 for Natural Resources in the 42nd Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was buildings.
A recording is available from Parliament.
NDP
Richard Cannings NDP South Okanagan—West Kootenay, BC
Right. It's my understanding from reading the results of some of your studies that they're actually done under pressure.
Director, Research and Development, Construction, National Research Council of Canada
There are loads on them.
NDP
Richard Cannings NDP South Okanagan—West Kootenay, BC
That's what I was trying to get at.
You mentioned smoke travel. Are those tests favourable in terms of smoke getting into elevator shafts and into stairwells? Are they comparable to normal readings?
Director, Research and Development, Construction, National Research Council of Canada
They're comparable to any other type of construction. Obviously, if you leave a door open, whether it's built out of wood, out of concrete, or out of steel, you're still going to get smoke in that stairwell. The structure itself is intact and will perform as well as any other structure. Other factors such as doors opening and people piercing holes in them, we can't control.
NDP
Richard Cannings NDP South Okanagan—West Kootenay, BC
I remember reading about, I think it was one of the NIST studies in the States, where they built a small mock apartment and set it on fire. It was done with mass timber construction, and it had the furnishings and everything in it. Basically, the results were that the furnishings burned and the fire went out. It didn't burn the structure at all.
Do you know about that study? Perhaps it's similar to the ones that were recently done. I'm just wondering, getting back to this encapsulated, exposed.... Was that done with exposed timber?
Director, Research and Development, Construction, National Research Council of Canada
Yes. We don't put furniture in there. We put in cribs, which simulate furniture, with the same fire load. That's exactly how we do it. We put what would be typically in a room. We know, roughly, what the fire loads are in rooms, and that's what we set on fire. In some cases, we actually have to go back and introduce more flame because it extinguishes faster than we expected it to. We are modelling based on what real life would be.
Liberal
Mary Ng Liberal Markham—Thornhill, ON
Thank you for the time.
I'm just going to ask a really brief question to both of you.
We heard earlier some testimony from the firefighters around concerns with a wood structure: that when modified it poses a different risk than construction made out of other materials like steel or concrete. Can you help us understand from the research that you have done what is being done, or whether that was also a consideration as you were doing your research? The issue was modifications after a building has been built.
Director, Research and Development, Construction, National Research Council of Canada
Obviously, any type of building, whether it's wood or concrete or steel, is going to have some modifications after the fact. Hopefully, in many cases, they'll draw a permit and do it correctly, but we know that that's not always the case. In the case of a wood building, for example, if somebody decides to tear out a wall and that wall is integral to a fire separation, it could have an impact on the way the fire is going to perform in that building, not unlike in any other type of building. We're hoping that the redundancies that are built into the building, such as the sprinkler systems and the fact that there are fire compartments between floors—hopefully they're not taking out a ceiling or something like that—are going to play into protecting that structure.
The tests that we conduct always have openings. We don't just build it, encapsulate it completely, and then do a fire test. We assume that there will be a certain percentage of openings for electrical fixtures, light fixtures, air vents. Those are all incorporated in the building, in the room, when we do the burning. That sort of mimics some of these situations, like where somebody puts a cable through a wall. It will mimic that type of assembly, yes.
Liberal
TJ Harvey Liberal Tobique—Mactaquac, NB
Thank you both for coming, of course.
I was just sitting here thinking about the testimonies that we've heard so far. One thing that we haven't heard much about is remediation. If a fire were to occur in a tall wood structure like Brock Commons.... Let's say there was a fire on the fourth or sixth floor of a laminated wood structure. Has there been any testing done or any analysis done of what the process for remediation would be to ensure that the structure is allowed to be repaired and to carry on? I'm assuming that if you have a fire in one bedroom of a 600-unit steel and concrete construction apartment building, you would have to make reparations that would allow that structure to stay in place while respecting the integrity that needs to be in place in that confined space. Has there been any testing done? What's the process if you have a fire in one portion of a tall wood structure? How does that look?
Director, Research and Development, Construction, National Research Council of Canada
That's actually a very good question because we've had discussions about this as recently as about two weeks ago. The big concern is not the fire. If you have a fire in a compartment, you remove those elements, like a box, and you replace them. The bigger concern is water. If you get water in the system and the water goes into the walls, what impact is that going to have on mould growth or any other type of concern in that building? We are now putting together a research study and some testing to actually see this. Does it dry out? Do we have mould? Is this really a concern?
We are in the process of determining what the requirements would be to ensure that we don't have mould growth. That's really the bigger concern: the water coming in through those walls. However, that's not just from fire. If somebody has a leaky washing machine, you're going to have the same concern.
With regard to fire, I don't think it's any different than any other building, whether it's wood or whether it's non-wood. You're replacing those pieces within that compartment, and the engineers will come back and certify that it's structurally sound.
Liberal
TJ Harvey Liberal Tobique—Mactaquac, NB
In the pictures that we've seen of those structures, a lot of times those laminated wood panels are, I don't know, 10 or 15 feet by 10 or 15 feet. They're massive panels, plus the supporting structure. If you have a supporting beam that's a laminated wood beam over top of that to support those individual panels and the last 15 feet of it is charred off, then how does that...? I understand what you're saying, but I don't really understand what you're saying. How do you repair that in a way that allows it to continue to be structurally sound?
Director, Research and Development, Construction, National Research Council of Canada
Well, the beams are generally built in pieces. You're not going to transport something that's 60 feet.
Director, Research and Development, Construction, National Research Council of Canada
You would take that piece out and replace it with another piece wherever it's charred.
The beauty with the CLT, the composite laminate timber, which is what we've been testing, is it just burns and creates a barrier. It acts as a protection for the wood, and then it burns and it creates another layer.
There is so much redundancy in that wood that it could probably burn for several hours before you've impacted the structural sufficiency of that beam. You come back and you replace those pieces, or you replace the entire beam. It can be done. Even in our labs, when we do burning when we build the CLT walls, we do the test and then the wall is still perfect. We take the wall and flip it around and do the test again. The wall is in great shape. We've done four hours of testing, we flip the wall, and we do another four-hour test with the same wall.
You get quite a bit of redundancy in that system.
Acting Vice-President, Engineering, National Research Council of Canada
If I may add, fundamentally, when you remediate, you fix, you repair, you have to go back to code. The engineers or builders will have to look at the code and make sure that the building is rebuilt to code.
Liberal
TJ Harvey Liberal Tobique—Mactaquac, NB
I recognize that. What I was trying to get at is whether you feel there could be a higher instance of inability to go back to the code.
Director, Research and Development, Construction, National Research Council of Canada
We don't believe so.
NDP
Richard Cannings NDP South Okanagan—West Kootenay, BC
Thanks for this unexpected opportunity.
I want to touch on seismic testing. You briefly mentioned seismic. I know it's a big concern in British Columbia where I'm from.
I wonder if you could comment on the seismic performance of these buildings and how you test that.
Director, Research and Development, Construction, National Research Council of Canada
We've just engaged in a collaboration with British Columbia and Natural Resources Canada to look at seismic, because there are a series of projects in B.C. on a fault that are running into some difficulty. How do they build these buildings completely out of wood and meet the high seismic zone requirements? We understand that.
Technically, it could be resolved. Right now they do it one-off. The engineer has to come in, look at that building, look at the seismic zone, and say how you will design it. Sometimes that will mean you're going to use a concrete base or it's not going to be all wood.
Over the next 12 months, NRC will come out with a technical guide that will address how to build completely out of wood in the high seismic zones. We have that on our radar. We're starting the work on that.
