E54. Structural Engineering with Special Guest Andrew (Part 2)

In this episode of the Building Design, Prime Time podcast Frank and Amelia delve straight into part 2 of Structural Engineering with special guest Andrew from RES Engineering who shares his experiences as a senior structural engineer.

Please watch the previous episode to listen to part 1 with Andrew from RES Engineering as this episode (part 2 of 2) follows on from the previous episode.

Frank and Amelia ask some challenging questions about the structural engineering industry, resources that are available and the types of work that requires structural engineering along with potential items that affects compliance.

About us
Prime Design is a building design company locally owned and operated in Tasmania since 2004.  Our goal is to share as much valuable information as possible about the process of building design, extensions, and more. We will talk about a different topic each week. To suggest a topic you would like us to talk about contact us at info@primedesigntas.com.au

Disclaimer
The information provided on this podcast is for educational and informational purposes only and is not intended to be a substitute for professional advice, individual circumstances, or remedy. We strongly suggest you consult a qualified professional before taking any action based on the information provided in this podcast. The views, opinions, and information provided in this podcast are those of the hosts do not necessarily reflect the official policy or position of any other agency, organisation, employer, or company. All content provided on this podcast is provided “as is” without warranty of any kind. We make no representations as to the accuracy, completeness, currentness, suitability, or validity of any information on this podcast and will not be liable for any errors, omissions, or delays in this information or any losses, or damages arising from its use. We reserve the right to change content or delete any information provided on this podcast at any time without prior notice.

Transcript

E54. Structural engineering with special guest Andrew (Part 2) 

[INTRO] (0:08 - 0:24)

Hello and welcome to the Building Design, Prime Time Podcast, focused on providing valuable information for anyone looking to undertake a new build or extension project. We'll share our tips, tricks and stories from a building designer's perspective.

[Amelia] (0:26 - 0:59)

Hello and welcome to the Building Design Prime Time Podcast. I'm your host Amelia and once again, we're joined by Frank Geskus. And we also welcome back Andrew, who is a structural engineer from Res Engineering.

And if you've been following along, we had part one of our podcast last week with Andrew. And so without further ado, we're going to dive straight into part two. Enjoy everyone.

[Frank] (0:59 - 1:23)

But the other thing you have to consider is stopping the building flopping in the breeze. You know, moving. And that's a thing a lot of people really don't understand. You know, your average person, builders get it, obviously, Hobart especially. It's in the Derwent Valley and you've got these steep sites hanging on the side of a hill. And they're really hanging out of the ground a long, long way. Get a decent wind through there. You can't afford this thing to move much.

[Andrew] (1:23 - 1:47)

Yeah, there's a whole section of the Australian Standard for structural loadings that just set out, you know, this is too much flex in a wall. This is too much sag in a floor. It's too bouncy. This is just on the limit. 

[Frank]

Yeah.

[Andrew]

So on. 

[Frank]

No one likes a bouncy floor. 

[Andrew]

It's one of the most complained about elements of a building. So it's very important to get the floor correct.

[Frank] (1:48 - 1:59)

And what's interesting about that, what is comfortable to one person is not comfortable to someone else. So structurally, it's fine. A bit bouncy. And some people think that's like vibration right through the floor. That's not the same.

[Andrew] (1:59 - 2:16)

Yeah. I had a friend ask me about a 100-year-old house where the floors were a bit tilting the other week. And I said, I don't know can you adjust to it? It's not right if it was a new building. 

[Frank]

But it’s 100 years old.

[Andrew]

Call the builder back. But it definitely changes from person to person.

[Frank] (2:17 - 2:25)

Also building to building. Because you've got something 100, 120 years old. The thing's going to creak. It's going to be a bit bouncy. It's definitely not going to be level because everything moves. 

[Andrew] (2:25 - 2:34)

Yeah. Sometimes there is a lot of out of squareness. When you're looking at old buildings and you go, gee, I wouldn't have noticed if I wasn't looking so hard.

[Frank] (2:34 - 2:48)

Yeah. Again, that's expectations too. Because in a new build, you can't afford to have too much flex in the floor if you've got a brittle finish on it. If it's all tiles, you can't afford it to move much because you're going to affect the grout. 

[Andrew] (2:48 - 2:50)

If it was nest eggs as well. They just go, well, is it right or is it not?

[Frank] (2:50 - 2:50)

Yeah.

[Andrew] (2:51 - 2:53)

It looks questionable to me. I want to make sure.

[Frank] (2:54 - 3:08)

Yeah, certainly. But it's making sure that it's right. It's a durability consideration in your build as well. You know, when you design something, if you know what the finishes are going to be, that actually changes how you do your design. Am I right in thinking that?

[Andrew] (3:08 - 3:37)

Yeah. Yeah, well, there's some things that might cause people to look twice. Like, say, a fine crack in a garage slab. Again, it's the current standards and systems that you follow. They're set up so that they don't add a huge amount of cost. They strike a balance between some slabs will crack and some won't at all.

And sure, it might make a difference to the end user, but we can accept to keep things so that we don't make real estate too pricey to build. We have to sort of draw the line somewhere.

[Frank] (3:37 - 3:58)

But also, when you're dealing with concrete, concrete's an interesting beast in itself. You talk about cracks. It's not unusual to have hairline cracks in a slab and it's structurally fine.

Shrinkage cracks, we call it. But again, it comes down to expectations of what you want it to look like. But concrete's concrete.

It's not a perfect product. There's so many variables in it and how it's cured.

[Andrew] (3:58 - 4:19)

Yeah, and sometimes you might get small gaps opening in brickwork around the joints and stuff. Sometimes it's a good news day because you go, well, yeah, it might catch your eye, but it's perfectly fine. It won't affect the use of the building or most people would just walk past it without noticing.

Nothing to see here. That's my job done.

[Frank] (4:20 - 4:36)

Yeah, but also, it's in a brand new home. You've polished concrete slabs. I think we've spoken about it before. They're a different beast altogether, and it's expected that that slab is absolutely perfect. No cracks. Free from cracks.

Free from any blemish. That is so hard to do.

[Andrew] (4:36 - 4:56)

Yeah, it's a conversation you want to have earlier on with the client. Sometimes there's a grey area where you go, well, depending on what finished product you want, do you want something to be blemish free or do you want it to be a bit more economical to build? Sometimes you have the freedom to sort of go the way that you feel on some of those decisions.

[Frank] (4:56 - 5:07)

Yeah, and it does come down to budget and how you prepare your concrete slab for polished, and what type of polish is cut, is burnished, whatever it may be. But it is an awful beast when it goes wrong.

[Andrew] (5:07 - 5:17)

Yeah, yeah. Concrete is sort of, if it goes well, it's fine. But if something goes wrong at the batching plant, it can be a major problem.

[Frank] (5:17 - 5:22)

Or even just the curing. That extraordinary weather day, and a whole bunch of stuff like that.

[Andrew] (5:22 - 5:29)

It's definitely a bad news day when you have to tell someone that whatever's gone wrong, that driveway's no good, rip it up.

[Frank] (5:29 - 5:56)

Yeah, no, and it's been done because the concrete mix is no good or has been poured correctly. It's just basically done incorrectly, rip it up, start again. That's an awful thing.

So, in your line of work, the way you're talking is that sometimes you get called out a fair bit on, hey, this doesn't look right, and you've got to make assessments. And you mentioned before about Australian standards, and I suppose your standards are one of your, well, the Bible is such of what you do.

[Andrew] (5:56 - 6:45)

Yeah, certain standards that you shall comply with. 

[Frank]

Yes. 

[Andrew]

But in the modern day, if you're doing a retaining wall, it has to have a certain factor of safety. It has to be stable to these guidelines. It can be quite complicated. But sometimes it's not just designing new houses and extensions.

There's a mix of the work that's out there for guys like me, people like me, is, well, this thing was built in a different time. It's currently looking like you see in front of you. Does anything need doing about this? Is it a danger? 

[Frank]

Yeah, so you're doing assessments on whether it's still reasonable or not. 

[Andrew]

That can be wall cracking in an old brick veneer building, or it can be retaining wall that's just opened up an alarming looking gap.

[Frank]

Yep. 

[Andrew]

Is it tilting too much?

[Frank] (6:46 - 6:49)

Change in circumstances behind it works around the site.

[Andrew] (6:49 - 7:20)

That's where it gets a bit of a dark art rather than a cut and dry. Does it meet the Australian standards and the building code for a new build? Yeah.

It becomes more of a, well, I can see this and I think this, but you better keep an eye on it. Or build a program for an ongoing assessment. That kind of forensic stuff can be very unsatisfying because based on what you can see, it's like sometimes the conclusion is, well, we don't know.

We just do nothing. But if it changes, call us or someone else back to have a look at it.

[Frank] (7:21 - 7:28)

I've got another question for you. What's your biggest frustration in the building industry? From a structural engineer's point of view, what's your biggest frustration?

[Andrew] (7:28 - 7:44)

Well, we work collaboratively with builders on the whole. Sometimes it's conflict with the builders over the journey. Sometimes they will have something embedded in their view of this does not need doing.

[Frank] (7:44 - 7:47)

Yeah, I don't need this. Why have you put this on the drawing?

[Andrew] (7:47 - 8:14)

Yeah, I know better. Sometimes there will be a thing that is introduced like, oh, now these type of slabs, you have to…

[Frank]

do this, 

[Andrew]

change it. 

[Frank]

Yeah, because the standard has changed.

[Andrew]

And probably the most challenging thing I've found is bringing builders along with you and some of those conversations with, well, you might not think that this concrete panel needs to be done a certain way, but that's where the engineer's point of view might be different from the builders.

[Frank] (8:14 - 8:22)

But also on the flip side, who's carrying the liability? Both are to a level, but at the end of the day, from a structural assessment, it's the structural engineer.

[Andrew](8:22 - 9:30)

Yeah, years ago when I was at the graduate level and you'd be the messenger almost, you'd go out to site and the builder would go, oh, I want to do this, I want to change it up, take it back to the boss. And you'd be like, no, don't do that for this reason. You go back to the builder and say, boss said no.

[Frank]

So you were the gopher to start with?

[Andrew]

Come on, don't make my life harder than it needs to be. 

[Frank]

But there's reasons for these things.

[Andrew]

Sorry, and as part of that conversation, that's why you reminded me of it, was my boss in one of these ongoing discussions that happened from time to time. He'd say, well, what, is he going to certify it? No. Well, there's your answer, do it my way. 

[Frank]

Yep, exactly. And they have to listen.

[Andrew]

Yeah. We often have different things driving us, like the building designer will have a certain vision for a way things are built. And the engineer will go, oh, that's really pushing the limits of what's possible. Are you sure you don't want to? 

[Frank]

Look at this alternative. 

[Andrew]

It can be a satisfying and collaborative exercise, or it can be two people going, oh, I don't understand why you're telling me. I can't have that. And the other person going, gee, it'd be easier if you saw it from where I'm standing.

[Frank] (9:31 - 10:02)

Well, and that's, I suppose, the working relationship, isn't it? What about, talking about frustration, is where your design and documents might have been ignored a little bit, and they've just gone ahead and done something because they got it cheaper and they did this before. And then you've got to go back, and this is no different, you were explaining how a builder was asking to do it another way, but they've gone ahead and done it, and not understanding or even trying to understand, and then they're trying to get away with it.

[Andrew] (10:03 - 10:25)

Sometimes it can be a minor issue. You might not even be exasperated with a builder. You might just go, oh, I know you did it this way on the previous jobs, but can you put another timber stud under there? Because it might be obvious to you that something's deviated from your perfectly produced plans, or someone might just misunderstand the way that the arrow's pointing or miss a note.

[Frank] (10:25 - 10:37)

The one that I've seen recently in the last few years where they've used, when they're building a stud frame, they've got to put straps in to tie it all together, but they're now using screws to put it together. Yet some of these screws don't have Australian certification.

[Amelia] (10:37 - 10:38)

Really?

[Frank] (10:38 - 10:39)

Oh, yeah.

[Amelia] (10:39 - 10:40)

Why have they not been specified?

[Frank] (10:41 - 10:46)

Well, they're not specified on the drawing, but they haven't got Australian certification to be used. There's no testing.

[Amelia] (10:47 - 10:48)

So why are we allowed to use them?

[Frank] (10:49 - 10:51)

But there's some that are. Don't get me wrong. There's some that are.

[Amelia] (10:51 - 10:51)

OK.

[Frank] (10:52 - 11:08)

And what's really interesting, some sales guy at a hardware store says, hey, use this, this is going to save you heaps of time. Yep, puts it in, doesn't check with the engineer, doesn't check if it's suitable and been tested in Australia. And, yeah, we've had some, seen some awkward conversations there because they didn't ask.

[Andrew] (11:08 - 11:12)

Been some large-scale examples of that with aluminium cladding.

[Frank] (11:12 - 11:15)

Yeah, well, there's a good example, swapping aluminium cladding, which are flammable.

[Amelia] (11:15 - 11:16)

Yeah, right.

[Frank] (11:16 - 11:39)

Aluminium composites. Everything's shipped so easily from country to country these days. But there's other products within the building industry with wall claddings that, and it's got better over the years where some of those wall claddings is pretty rubbish or the windows aren't Australian standard. Tapware is not Australian standard. All things are installed into the house. Putting cheap shit in there.

There's no other way of putting it.

[Amelia] (11:40 - 11:40)

Yeah, yeah.

[Frank] (11:40 - 12:05)

It's got to be certified. Everything's got to be certified. There's a reason. Your drawings are certified. My drawings are certified. Every consultant we use certifies their work.

Every product goes into your house, has to be certified. And it's the only way to do it reliably. As soon as you step out of that, ie by stepping away from the engineer's drawings or change something on the building drawings, that may have a detrimental effect on the house and its longevity, but could make it a sick house too.

[Amelia] (12:05 - 12:06)

Yeah.

[Frank] (12:06 - 12:09)

It may not fall to pieces, but it might make you sick.

[Amelia] (12:10 - 12:16)

It could be a massive domino effect. It doesn't just affect one area, multiple areas.

[Frank] (12:16 - 12:24)

And that's where builders, there's quite a few builders just following it. There's no problem. They're doing all the right things. But you get the occasional ones that just seem to go, no, I can do this my way.

[Andrew] (12:24 - 12:48)

Yeah. We're pretty, pretty lucky as an industry. There's a lot of, I guess, a timber framing code that covers a lot of stuff that we can't show on all our plans and drawings.

There is a fair bit of protection for, we show the important bits and specify beam sizes, but some things are sort of trusted that practitioners, that, well, the builders and suppliers aren't going outside the...

[Frank] (12:48 - 12:50)

Most builders know that stuff well. They should do anyway.

[Andrew] (12:50 - 13:02)

Yeah. That's why trends sort of come up if everyone's using this kind of sisalation under the wall panels, because it's cheapest and it does the job and everyone sort of...

[Frank] (13:02 - 13:29)

But there's the problem. It depends what's been supplied by suppliers. Suppliers aren't controlled or regulated because talking to a building surveyor, we have to have a breathable wrap around a house. Years ago, we used to use a sisaltion product. This is only last year. I was talking to a building surveyor he says, you're not going to believe what I had to do. I had to tell them to pull off all the external cladding of a house that's been built because they put the old sisalation on it and it's illegal now. And the excuse was, well, this is what was supplied from the hardware store or the hardware supplier.

[Andrew] (13:30 - 13:34)

Stuff like that where you hope the same mistake doesn't happen over and over.

[Frank] (13:35 - 13:36)

But think of that.

[Amelia] (13:36 - 13:38)

I mean, it could have happened lots of times.

[Frank] (13:38 - 13:41)

But he did... It was twice within a couple of months.

[Amelia] (13:41 - 13:41)

Wow.

[Frank] (13:41 - 13:51)

Two different projects, different builders. One, he caught it early. He was there for a framing and they were just putting it on. He saw it and says, no, you're not putting that stuff on. It's illegal. Another one, they already started putting the cladding on.

[Amelia] (13:51 - 13:51)

Oh, wow.

[Frank] (13:52 - 13:52)

Yeah.

[Andrew] (13:52 - 13:56)

One of the challenges that we face, things changing and...

[Frank] (13:56 - 14:00)

Yeah, but if hardware stores aren't regulated or suppliers aren't regulated...

[Andrew] (14:00 - 14:07)

No, there's no one at the border or in the postal services checking what they're bringing in and out.

[Frank] (14:07 - 14:28)

Yeah, exactly. But also what they're supplying. They're just trying to get rid of the product. And that's no different with, I've seen trust manufacturers or timber merchants replace steel with timber as well that's based off the engineering drawings and they've done a substitute without permission. And that has a big effect on the building potential. So that's the thing we're battling that should never happen.

[Amelia] (14:28 - 14:33)

And I'm guessing building surveyors will pick up on this stuff when they do their checks. Is that right?

[Frank] (14:33 - 15:00)

Should do. When they do the framing inspection. Yes. You'd think they do. But sad to say, it's not 100% foolproof. 

[Amelia]

Well, I guess if you can't see it...

[Frank]

If you can't see it, 

[Amelia]

It’s a problem. 

[Frank]

Yeah, exactly. But I've seen other surveyors and they're like absolute hawks. I remember one job in particular, high wind, the battens, the pieces of timbers that go on top of your trusses or rafters before you put your roof sheeting or tiles on. They didn't put the right nail sequence in there.

[Amelia] (15:00 - 15:01)

Really?

[Frank] (15:01 - 15:19)

Yep. So instead of one nail, it was specified two skew nails due to the wind. And this was many, many years ago. They already had the sheeting on and partly on and they said, well, you haven't put the right nails in. So then it's got the potential of pulling the roof off. So we had to help them come up with a solution by putting a screw in from underneath to tie it together.

[Amelia] (15:19 - 15:20)

Oh, wow.

[Frank] (15:20 - 15:29)

Rather than pull the sheeting off. And that was just a mistake they made. They just missed it on the drawings.

That's all it was. They weren't trying to do the wrong thing. But this is where you've got to study the drawings, isn't it?

[Andrew] (15:30 - 15:43)

Yeah, and it's an argument for the continued professional development we have to do because when problems arise, where you go, well, whoever the powers that be go, this is a problem we don't really want duplicated. 

[Frank]

Of course.

[Andrew]

Better put the information out there.

[Frank] (15:44 - 15:58)

But also it's usually just one-off problems like that. I bet that builder never make that mistake again. It's when things are supplied, they don't think, you know. So what suggestions can you give someone choosing or wanting to engage a structural engineer? What should they be looking for, Andrew?

[Andrew] (15:58 - 17:03)

If you have access to word-of-mouth kind of anecdotal information, same as if someone was going to look at a new house build, they'd go and have a look at the portfolio of what a building designer had done before, saying, I think I need engineering advice on my retaining wall or my extension, or, you know, I want to see what's possible. If you know any building designers or builders that are engaged in or that are in the construction industry at present, just go, who do you know? Do you know a company or a person?

[Frank]

Reputable person. 

[Andrew]

That you can say, I'll do what all professionals are signed up to do, which is perform ethically and be easy to deal with. 

[Frank]

Yeah, so word of mouth.

[Andrew]

Yeah, yeah. Ask your builder mate. 

[Frank]

Because they're also a good judge of, you know, people are any good, any engineers that are good at what they do.

[Andrew]

Got any engineers you trust to do a good job is the easiest way. We have to be accredited through the Department of Justice's building accreditation list. So you can also do a Google search on any trades.

[Frank] (17:03 - 17:07)

But they've got to be licensed. But they've got to be licensed. Like I've got to have a license. You've got to have a license.

[Andrew] (17:07 - 17:32)

Yeah, if I was getting a bathroom done, and I was getting quotes or whatever, I'd definitely be considering, are they a registered builder or are they not? Same with engineers. If you're talking to one about doing a quote for a new house certification or, I don't know.

[Frank]

Insurance.

[Andrew]

Getting a kit home. Well, that follows the accreditation.

[Frank]

It does. 

[Andrew]

You can't operate without insurance.

[Frank] (17:32 - 17:35)

No, you can't. But are they licensed to do your area?

[Andrew] (17:35 - 17:46)

I think, as with anything that's ever been done, where people are involved, it's gone wrong before. 

[Frank]

True, true.

[Andrew]

If you're being super diligent, you could say, you're not operating illegally, are you?

[Amelia] (17:48 - 17:51)

Do you think they would honestly answer that question?

[Frank] (17:52 - 17:59)

Well, I'm seeing it in other parts of the industry, though. People aren't operating without licenses. Anyway, that's a whole other discussion.

[Andrew] (18:00 - 18:06)

I think in Hobart I've yet to hear of anyone going around offering structural services.

[Frank] (18:06 - 18:13)

No, it's probably not structural. But more in so far as building and home handyman, I've seen it more in plumbing.

[Andrew] (18:14 - 18:25)

Word of mouth will hopefully weed out any of those more disturbing problems. Yeah, well, it is a disturbing problem. People misrepresenting what they can and can't do.

[Frank]

Yep, totally.

[Amelia](18:25 - 18:31)

So where can we find Res Engineering? Do you have social media or website?

[Andrew] (18:32 - 19:01)

Yes, we've got a few. I only learned yesterday we have an Instagram page. 

[Amelia]

You do? 

[Andrew]

Which I promptly followed. 

[Amelia]

Yes. 

[Andrew]

I should have noticed the camera logo. Oh, that's Instagram, right? No, we're on Facebook and LinkedIn, and we also have a website, resengco.com.au. 

[Amelia]

Well done. 

[Andrew]

It's another sign that someone's not a front for something else if they've gone to the bother of putting up who they are and what they do.

[Amelia] (19:01 - 19:01)

A website and social media.

[Andrew] (19:02 - 19:06)

On the internet, the world's most trusted provider of information.

[Frank] (19:08 - 19:12)

What are you saying? You tell me there's people that are telling untruths on the internet?

[Andrew] (19:13 - 19:15)

I hate to be the bearer of bad news on that one.

[Frank] (19:15 - 19:20)

You're breaking my heart, mate. I'm shattered. 

[Amelia]

Oh dear.

[Andrew] (19:20 - 19:27)

And elderly relatives that ask me the same question. The answer is always have an appropriate level of cynicism.

[Frank] (19:30 - 19:37)

I suppose it brings back that I just don't believe everything you read in the paper. For those people that remember what a paper is.

[Amelia] (19:38 - 19:38)

What's a paper?

[Frank] (19:39 - 19:44)

Don't go there. We used to read all our news. 

[Amelia] (19:44 - 19:58)

Exactly. All right, we might wrap it up there. We've been talking for a while now. Thank you so much for coming in, Andrew, and having a chat to us about structural engineering.

Are there any resources available for anyone that wants to learn a little bit more about how it all works?

[Andrew] (19:58 - 20:06)

The closest I could say to that is forensic engineering. You quickly know if you're interested in it or not.

[Amelia] (20:07 - 20:09)

It might not interest a lot of people.

[Andrew] (20:09 - 20:23)

It's a bit dry, but you can find some resources on there about when buildings don't behave themselves. The closest I could find to light reading, when you warned me that question might come up.

[Frank] (20:24 - 20:28)

Actually, I think Penguin had a book out, which was Why Things Don't Fall Down.

[Amelia] (20:28 - 20:30)

That sounds like a good book.

[Frank] (20:30 - 20:31)

It was. It was a fascinating book.

[Amelia] (20:33 - 20:37)

Would it be fascinating for everyone else, Frank, or just maybe you and Andrew?

[Frank] (20:38 - 20:39)

Probably not for a lot of people it’s why would you read this? If you're in the game, it's quite interesting.

[Andrew] (20:40 - 20:51)

It's a hard question, because what an engineer might find interesting, they just know deep down. Sometimes the general public won't.

[Frank] (20:51 - 20:52)

They'll look at you funny.

[Andrew] (20:53 - 20:57)

Same with us in geologists. 

[Frank]

Yes, very true.

[Amelia] (20:57 - 21:08)

All right. Thank you so much for coming in today, Andrew. And once again, Frank, thank you for joining us for another exciting episode. Thanks for listening to the Building Design, Prime Time Podcast. We'll catch you next time.

[Frank] (21:08 - 21:10)

Thanks, Amelia. See you. 

[Andrew]

No problem. Cheers. 

[OUTRO] (21:20 - 21:23)

You're listening to the Building Design, Prime Time Podcast.