E57. Using concrete and concrete products

In this episode of the Building Design, Prime Time Podcast Amelia and Frank discuss some hard truths about concrete and concrete products. 

Frank talks about his experience working with different concrete products and the pros and cons of using concrete in different ways around the home from external claddings to floor slabs, benchtops and more. 

It's an episode not to be missed, so be sure to subscribe so you don't miss an epsode! 

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

E57. Using concrete and concrete products 

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

Hello and welcome to the Building Design Primetime 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 designers perspective.

(0:28 - 0:43)

Amelia: Hello and welcome to the Building Design, Prime Time podcast, I'm your host Amelia and once again we're joined by Frank Geskes.

(0:43 - 0:45)

Frank: Hey Amelia, how are we?

(0:45 - 0:51)

Amelia: Oh look, I'm a bit upset. Why are you upset? Look, I really have to have a hard conversation with you.

(0:52 - 0:53)

Frank: Oh seriously.

(0:54 - 0:55)

Amelia: We're going to talk about concrete.

(0:56 - 0:59)

Frank: That is going to be the worst lead in ever, so come on.

(1:00 - 1:03)

Amelia: Did I have anyone worried there for a second?

(1:05 - 1:07)

Frank: Air all my dirty laundry about concrete.

(1:08 - 1:12)

Amelia: That's really hard stuff isn't it? Hard to listen to.

(1:12 - 1:25)

Frank: You're cracking me up. Okay, what do you want to know about concrete? I have a little bit of knowledge in the industry and experiences and I've seen the good, the bad, the ugly and what were you thinking?

(1:25 - 1:35)

Amelia: Yeah, I imagine you have and look, there's just so much in the way of products available on the market that are based around cement concrete.

(1:35 - 1:36)

Frank: Yes.

(1:36 - 1:46)

Amelia: And what are the pros, what are the cons, what are some options available, kind of where do you start for anyone that's looking to start a new build, extension, et cetera?

(1:47 - 2:24)

Frank: Yeah, fair enough. Well, look, at the end of the day, concrete's an essential part of what we do here in Tasmania, definitely, because your floor may be what we call a concrete slab, okay? It's all concrete.

Amelia: Yeah. 

Frank: Nice and hard, does its job, happy days. Then you can do things with that slab, but it's not just the slab, it could be just the footings and then you've got bricks and then you've got a timber floor so you don't see the concrete.

But then you've got a beautiful concrete driveway and it's been really amazing what creativity has been happening with exterior concrete finishes. I know myself, I've got a coloured concrete driveway. We put colour through it.

(2:24 - 2:26)

Amelia: Yeah, there's heaps of options.

(2:26 - 2:27)

Frank: Heaps and heaps of colours.

(2:27 - 2:30)

Amelia: You need to look at everyone's driveways, people. There's so many options.

(2:30 - 2:50)

Frank: Yeah, it's great. Exposed aggregate is very popular. So all different types of aggregates and they blow the top off and you get this pebble finish on it or in some cases, some people like using bluestone, riverstone.

I've seen glass, I've seen marbles put into concrete and ground down so you've got glass in there. All different types of coloured glass too.

(2:51 - 2:51)

Amelia: Wow.

(2:51 - 3:03)

Frank: Yes. I've seen that in a house that they did it with a colleague of mine. They had a coloured concrete plus an aggregate and they put the blue marbles as such in there.

(3:03 - 3:05)

Amelia: Wow, that would look cool.

(3:05 - 3:10)

Frank: Yeah, but there's lots of options of this stuff. Remember the old terrazos from the 60s?

(3:10 - 3:10)

Amelia: Yes.

(3:10 - 3:13)

Frank: That's coming back in different fashions as well. It looks freaking awesome.

(3:14 - 3:15)

Amelia: Oh, it looks really cool.

(3:15 - 3:39)

Frank: Yeah, and you just go round people's driveways and look at the creativity because you can stencil it, you can stain it, you can colour it, you can polish it, you can burnish it, you can put a broom finish, trowel finish, even staining it or putting all sorts of stuff in the mix to make it look interesting. Wow. And some of those things are really hard to do, to do really well because you only get one crack at this.

(3:40 - 3:40)

Amelia: Really?

(3:41 - 3:41)

Frank: Well, think about it.

(3:42 - 3:43)

Amelia: You only get one crack.

(3:43 - 3:43)

Frank: Yeah.

(3:44 - 3:49)

Amelia: That was bad. 

Frank: I wonder if you're going to pick that up. I wonder if you're going to pick that up.

Amelia: I did well to pick it up for a Friday.

(3:50 - 4:29)

Frank: So you just think about it. You've got this concrete mix comes out of the back of a truck or if they're mixing it on site and it's going to go off. It's going to set hard and they've got a certain time frame to get it down, get it all level and then get the finish right and that could be after hours or a day or whatever.

They've then got to complete the finish on the roll. It could be looking at a high-pressure cleaner, blow the top off, expose the aggregate. It could be the trail finish.

It could be the polished finish later on where they've got to grind it or burnish it. What if they're going to stain it? What happens if they're going to put the stain over the top or the stenciling?

(4:29 - 4:30)

Amelia: Yeah.

(4:31 - 4:51)

Frank: So these guys in concreters, they're highly skilled at what they do, concreting. Some of these guys look like they drag their knuckles and don't have the arse in their jeans. But to be fair, some of these guys are really skilled and really passionate about what they do with concrete.

They can read the concrete and how it's going off.

(4:51 - 4:56)

Amelia: And I imagine the humidity, the moisture level, the weather.

(4:56 - 5:02)

Frank: It rains. The mix. If the mix is wrong, I've seen mixes go wrong and cause all sorts of mayhem.

(5:03 - 5:03)

Amelia: Really?

(5:03 - 5:32)

Frank: Yep. And then you're in big arguments and stuff like that. It dries out too quick.

The moisture content's wrong. Puts a thing called a plasticizer on it to get it to cure. That's not always perfect.

That curing process isn't done well. So I've seen slabs on a commercial site, one for one building. Perfect slab.

Mickey Mouse. Done as per you'd expect. Other side, looks like crazy paving.

(5:33 - 5:36)

Amelia: Really? Yep. So many variables that affect that.

(5:36 - 5:36)

Frank: Different weather.

(5:36 - 5:37)

Amelia: Yeah.

(5:37 - 5:42)

Frank: Different weather, different mix. Who knows? They said they did it exactly the same.

Can't answer.

(5:43 - 5:44)

Amelia: Yeah, that's odd.

(5:45 - 5:47)

Frank: So what do you do then when you've got cracks in it?

(5:47 - 5:48)

Amelia: I don't know. What happens?

(5:48 - 6:12)

Frank: Well, there are ways of dealing with it and micro cement filling it, pressure cleaning it, micro cement it. Or sometimes you've got to re-coat and put a coating over the top. But it depends what the end use is.

So I'll bet you if you've got a concrete slab for your house and you've got carpet everywhere, if you pull up your carpet, actually don't, but if you did, I'll guarantee you're going to see some hairline cracks in there. It's called shrinkage cracks.

(6:13 - 6:14)

Amelia: So that's completely normal?

(6:14 - 6:15)

Frank: Yeah, pretty normal.

(6:16 - 6:17)

Amelia: So when should people be worried?

(6:18 - 6:20)

Frank: When it gets past three millimetres.

(6:21 - 6:21)

Amelia: Okay.

(6:21 - 6:26)

Frank: There's an Australian standard for crack control as such for concrete.

(6:27 - 6:29)

Amelia: I'm glad you added for concrete at the end of that sentence.

(6:29 - 7:08)

Frank: Yeah, that could have been a bit. So there is an Australian standard which alludes me that you measure the size of the cracks to say, well, that's determined as a shrinkage crack. That is movement.

It's cracked through the whole thing. And then it's catastrophic. But this is where your local friendly engineer would be able to have that chat.

Yes. Whoever worked on the project would be able to give that advice. Now, great giving the advice.

What do you do afterwards? Well, you've got to determine what it is first before you know what to do. So, yeah, you could have, it's called plastic shrinking cracks, drying shrinkage cracks, settlement cracks or structural cracks.

You don't want the structural ones.

(7:09 - 7:11)

Amelia: I was going to say, they don't sound very good at all.

(7:11 - 7:18)

Frank: No, it could be excessive loads or foundation movements. But let's talk about the fun stuff. Make it look nice.

(7:18 - 7:19)

Amelia: Yes, the fun stuff.

(7:19 - 7:50)

Frank: So again, you've got to find a quality concreter who's got well-versed and well-experienced in doing concrete for you, especially when it's exposed. Because, like I said, you get one crack at this. And a lot of times it's exposed.

It's in your driveways. It's in your footpaths. It can go in your retaining walls and to your garden beds.

But you know where it gets crazy, and you would have seen this, is where people decide to do concrete benchtops for their kitchen or concrete dining tables or outdoors.

(7:50 - 7:52)

Amelia: They sound ridiculously heavy.

(7:52 - 8:18)

Frank: Yeah, or, oh, that's right. I forgot to mention this before. I remember doing a house with another designer, and we helped arrange a concrete bench for the kitchen.

And it was cast on site. So the whole house was polished and whatnot. And then they made all this formwork to make this big concrete bench.

Sink was inlaid. The bench went out through the wall of the house, and then formed the bench for the barbecue area.

(8:19 - 8:19)

Amelia: OK.

(8:19 - 8:24)

Frank: And then the window, then the glass, met top and bottom, and it looked super trick.

(8:24 - 8:25)

Amelia: I reckon.

(8:25 - 8:27)

Frank: But do you want to like it for a long time?

(8:28 - 8:30)

Amelia: Yeah. It's not easy to change, is it?

(8:30 - 8:42)

Frank: No. Well, especially with a big solid lump of concrete. And considering how many certain elements of our society wants to have a new kitchen every 10, 20 years, you're stuck with this concrete bench.

(8:43 - 8:45)

Amelia: Yeah. You definitely want to love it.

(8:45 - 8:48)

Frank: You want to really like it. And it also controls your whole decor.

(8:49 - 8:49)

Amelia: It does, yeah.

(8:49 - 8:54)

Frank: And if you don't like your kitchen sink, it's cast in there.

(8:55 - 8:56)

Amelia: Bit of a problem there.

(8:56 - 9:45)

Frank: It is. It is. So it can be used in so many great places and look amazing.

One thing I need to point out, if you're getting a dining table or those types of things, they are usually made in controlled conditions. So the mix is controlled, the temperature is controlled, it's cured. So it's a different process.

It's like when you order a precast panel for your house. If your precast panel is something that's made at a factory and it's a panel of concrete. You see lots of warehouses.

We've done precast panel houses before too. 

Amelia: Really? 

Frank: So all the walls are precast.

Amelia: Oh, wow. It's not a bad way of doing it. It's built like a bomb shelter.

And then you can bolt the roof off the top of it, windows in. The challenge is how do you insulate it? So then you've got to batten out in line to put the insulation inside.

(9:46 - 9:52)

Amelia: How would you make it look pretty on a house though? I don't see that as a very pretty finish.

(9:52 - 9:59)

Frank: Well, the beauty of precast, if you just look pure trowel finish, no. But why can't you colour it?

(9:59 - 10:00)

Amelia: Well, that's true.

(10:00 - 10:09)

Frank: Put a texture in it. Because a lot of these professional precasters have got all these finishes that you can put on the outside.

(10:09 - 10:11)

Amelia: So you can make it a bit more interesting.

(10:12 - 10:38)

Frank: Oh, 100 per cent. But you design the house to be interesting in the first place with those concrete finishes. 

Amelia: Yes.

Frank: Now, there's nothing stopping you on certain areas that you don't have the concrete finish and you put another cladding over the top. Oh, that's a good point too. But I've also seen the other side where you're doing more conventional construction and you use precast panels as features like around your entry.

So you put concrete walls, concrete roofs, that type of stuff, and it forms part of the entry of the house.

(10:38 - 10:47)

Amelia: That just actually reminded me of really old houses that you probably see around Launceston and they have that panel like above the front door that's made of concrete.

(10:47 - 10:51)

Frank: Yes, the weatherboard house and you've got a concrete slab as the entry roof.

(10:51 - 10:51)

Amelia: Yes.

(10:51 - 10:52)

Frank: You're dead right.

(10:52 - 10:54)

Amelia: There's been heaps of those. There's so many of those.

Frank: (10:54 - 10:55)

And they're sitting on timber.

(10:55 - 10:56)

Amelia: Well, if they're weathered.

Frank: (10:56 - 11:08)

Yes, they're sitting on timber. 

Amelia: Really? Yes, 

Frank: Seriously. You see the ones incorporating the brickwork and they've got concrete, which is a ring beam around the top. But you see weatherboard houses with a concrete slab.

(11:08 - 11:10)

Amelia: How is that even holding it up?

(11:11 - 11:13)

Frank: Been there for 70-plus years.

(11:13 - 11:14)

Amelia: So it must be all right.

(11:14 - 11:15)

Frank: There's a lot of those post-World War II houses.

(11:15 - 11:16)

Amelia: Yes.

(11:16 - 11:17)

Frank: And they're still there.

(11:17 - 11:19)

Amelia: Yeah, a bit crazy, isn't it?

(11:19 - 11:21)

Frank: Well, do it once, do it right.

(11:21 - 11:22)

Amelia: Yeah, true, true.

(11:22 - 11:47)

Frank: I know it sounds odd, but it's very doable. And you've got to remember the timber they used back then was a lot stronger. They used ancient Tasmanian hardwoods compared to we use, predominantly we use radiata pine, to be fair, is the greatest product in the world.

But it's done for a price purpose, price point for a build. Whereas Tasmanian hardwood, beautiful stuff.

(11:47 - 11:48)

Amelia: Oh, so good.

(11:48 - 11:52)

Frank: But the stuff that we get now is like virtually furniture grade. It's magnificent.

(11:52 - 11:53)

Amelia: Yeah.

(11:53 - 12:02)

Frank: Still not as good as the really old stuff they had. It was from old growth forests. 

Amelia: Yes.

So that has other problems, getting old growth forests. We can't do that anymore.

(12:02 - 12:03)

Amelia: No, no, there's definitely limitations.

(12:03 - 12:05)

Frank: Nor should we do it anymore.

(12:05 - 12:06)

Amelia: Yeah, I agree.

(12:08 - 12:14)

Frank: So concrete's used in so many crazy ways. And I actually love it in backyard barbecues or alfrescos.

(12:14 - 12:15)

Amelia: As a slab or?

(12:16 - 12:18)

Frank: No, as the bench and put your barbecue in it.

(12:18 - 12:19)

Amelia: Well, that's a good point.

(12:19 - 12:25)

Frank: And tables. It looks really good. And two, it's easy to wash.It handles the outside really well.

(12:26 - 12:31)

Amelia: Yeah, well, that's a good point. There's very little maintenance on concrete really, is there?

(12:31 - 12:35)

Frank: Other than you don't want to get the fat spattered from your barbecue on it.

(12:35 - 12:36)

Amelia: That's no good for it?

(12:36 - 12:39)

Frank: Well, think of it, it's like oil, oil on concrete stains.

(12:39 - 12:40)

Amelia: Oh, yeah, it would.

(12:40 - 12:51)

Frank: So you've got to put a sealer on it. Yes. One thing I do recommend, I've got to share this story with you, and I might have already, I can't remember, but don't ever do a polished concrete driveway.

(12:51 - 12:54)

Amelia: I think maybe you've mentioned this before, but I can't remember the reason why.

(12:54 - 12:57)

Frank: So think of a driveway going from the street.

(12:57 - 12:57)

Amelia: Oh, slippery.

(12:58 - 13:00)

Frank: Yeah, a little bit of water on polished concrete.

(13:00 - 13:01)

Amelia: Slippery.

(13:01 - 13:05)

Frank: You know, walking your thongs, you'll be flat on your tail really quick.

(13:05 - 13:22)

Amelia: Yeah, I was actually surprised. One of the houses that we went to visit probably late last year, inside the garage had polished concrete, and I can imagine you drive in with a car that's been raining outside, it's wet, and you step out.

(13:23 - 13:25)

Frank: Step out, you'd be lucky to stop the car.

(13:25 - 13:26)

Amelia: Yeah, true, yeah.

(13:26 - 13:30)

Frank: That's my experience when I went on this driveway. I nearly lost my car into the brand-new lawn.

(13:30 - 13:31)

Amelia: Oh, my goodness.

(13:32 - 13:56)

Frank: But I don't have my own house. I go into my garage. I've just got troweled concrete.

I walk in there with thongs, a little bit of water after washing the car, and whoo-hoo. Yeah, a bit slippery. It's like an ice skating rink.

So you've got to be careful with concrete in a lot of ways, and you've got to get the right surface. You've still got to put protective coatings on it at times as well. The popular thing we have, though, people love the polished concrete in their house.

(13:57 - 14:00)

Amelia: That's been really popular for flooring, hasn't it?

(14:00 - 14:01)

Frank: Yeah, and some people think it's really cheap.

(14:02 - 14:03)

Amelia: Oh, it's not cheap.

(14:03 - 14:04)

Frank: It's not cheap at all.

(14:04 - 14:04)

Amelia: No.

(14:04 - 14:13)

Frank: No, no. And you've got different types. You've got pure, where you cut the concrete, and you've got the other ones that you actually burnish the concrete, so you're literally polishing the top to buffing it to a gloss.

(14:13 - 14:13)

Amelia: Yes.

(14:14 - 14:16)

Frank: I love that finish. It's so good.

(14:16 - 14:17)

Amelia: That does look nice.

(14:17 - 14:41)

Frank: A lot of work, and you need some real experts doing that as well. But the expectations, I've got to share expectations of all this too. Concrete is one of those products that if, like I was saying, it's a wet product, it's curing into something, and if you lose control of the curing, it will potentially have plastic shrinkage cracks or drying shrinkage cracks in there, and you don't want them.

Bad luck, you can't help it.

(14:42 - 14:48)

Amelia: I've got another question for you. What about concrete in a corrosive environment, like if you were at the beach?

(14:49 - 15:43)

Frank: Yeah, you're out near the beach, so it has to be – there's a specification for that. For one thing, you use a higher grade concrete, so normally with houses, 25 MPa. It's classes by strength, MPa.

So you've got to start looking at minimum 32 MPa or even greater because there's a denser concrete, so the salt can't get through. But also how the reinforcement that's put in there is actually encased further inside the concrete. There's greater cover to the concrete to protect the steel because it is just basically…

Amelia: Because it would rust, wouldn't it? 

Frank: Yeah, that's what we commonly call is concrete cancer, and you'll see that on old buildings around the water. There's a good chance they may get concrete cancer.

That's where concrete spalls, splits, and you'll see all this rusty stuff. The salt as such can get in there. Nowadays, we look at stainless or fibreglass reinforcement.

(15:43 - 15:45)

Amelia: Yeah, there's other options now, isn't there?

(15:45 - 15:57)

Frank: Yeah, so if I'm going near the coast, I'd definitely be looking at fibreglass, and there is structural fibreglass reinforcement available to be able to do that, so you're not going to have that corrosive challenge.

(15:57 - 15:58)

Amelia: Yeah, that's cool.

(15:59 - 16:10)

Frank: Yeah, but that's a great question. It has to be considered. Now, I'm saying that's every part of your house when you're in a corrosive environment. It always has to be considered on what you use, how you coat things. Definitely. Very important.

(16:11 - 16:16)

Amelia: You can refer back to our hazardous conditions podcast. 

Frank: Oh, wow.

(16:16 - 16:17)

How long ago was that?

(16:17 - 16:19)

Amelia: It was only a couple of podcasts ago.

(16:19 - 17:01)

Frank: Was it really? Okay. Yeah, building near the coast. There you go. So with concrete, do your research on what you like for your finish. It could be inside your house.

It could be your paths. It could be your driveway. It could be inside your garage.

You might have a feature wall. It is utterly amazing the variety of things that can be done in concrete. One of the best examples, concrete is used a lot in commercial buildings, so your public buildings.

So if you go out to, well, I could say any city anywhere, there's concrete or stone, but you use a lot of concrete. It's really – I love some of the creative way they use it in landscaping, public spaces, buildings, especially in the foyers and things like that.

(17:01 - 17:08)

Amelia: So when is it important that a concreter consult a structural engineer?

(17:09 - 17:11)

Frank: Or when it's actually a structural application?

(17:11 - 17:19)

Amelia: Because I can imagine sometimes obviously for the obvious things like flooring, that's all done beforehand.

(17:19 - 17:21)

Frank: It's designed. It has to be designed.

(17:21 - 17:30)

Amelia: But what if you're a landscaper and you're organising a base for a sculpture or something weird like that? There you go.

(17:30 - 17:41)

Frank: Well, then you'd be talking to a structural engineer about, well, what's it holding? Same with a retaining wall. It's holding back the earth and any moisture behind there.

It's got to hold all that back.

(17:41 - 17:44)

Amelia: I wonder whether actually landscapers would do that.

(17:44 - 17:46)

Frank: The quality landscapers do.

(17:46 - 17:46)

Amelia: Yeah.

(17:48 - 18:14)

Frank: The real quality ones definitely do. I know that because they want the stuff to last. So it's for them to – see, that's also down to who designs – is it a landscape architect designing it?

Now if it is, they do do the right thing and get retaining walls designed and certified. Because retaining walls, just as a tip there, if you've got a retaining wall, it has to have a level of certification. How do you know it's going to hold?

(18:15 - 18:16)

Amelia: Yeah, that's a good point.

(18:16 - 18:53)

Frank: But there's certain manufacturers and block manufacturers, so digressing here, and I'll make a shout out to one of our local manufacturers who's done really cool things and cool products, is Island Block and Pavings. They have a magnificent range of products, including recycled glass in their concrete block products. Looks amazing.

They have retaining walls, call it buy-off-the-shelf, that already are pre-engineered, and they have conditions in there and they tell you how to build a retaining wall up to a maximum height. I think it's about 1.1 metres. And they are generally quite suitable for a lot of applications.

(18:54 - 18:54)

Amelia: Okay.

(18:54 - 19:15)

Frank: Okay. But when you're building something from scratch, like out of, hey, I want a concrete-finished retaining wall, it has to have a level of engineering because you've got to put the reinforcement in. Same with concrete block walls, you know, just straight blocks that are stacked on top of each other and you fill it with concrete, well, they're going to have reinforcement in there.

But that reinforcement all has to tie into a footing.

(19:15 - 19:19)

Amelia: Yeah, that's true. It's all the footings, the foundation of it all.

(19:19 - 19:28)

Frank: Yeah, so whatever's pushing on the back, it's going to hold whatever it's being pushed by. Then it's just as critical to get the drainage right on those as well.

(19:29 - 19:29)

Amelia: Sure.

(19:29 - 19:33)

Frank: So, again, concrete's involved in all of those things.

(19:33 - 19:36)

Amelia: Yeah. What about the different types of concrete?

(19:37 - 19:37)

Frank: Yep.

(19:37 - 19:44)

Amelia: Like I know there's products out there that are a little bit more environmentally friendly, like you've got, I think it's called Hempcrete.

(19:45 - 19:46)

Frank: Oh, that's a very different product.

(19:46 - 19:48)

Amelia: It doesn't have concrete in it?

(19:49 - 20:07)

Frank: You're catching me on the hop there. I've seen a couple of buildings put together where they've done Hempcrete and it looks utterly amazing. The formula and stuff they use eludes me.

Tell you what, there is a big push for that in Tasmania. There's the Hempcrete guys in Tasmania. We need to get them on the show.

(20:08 - 20:09)

Amelia: We need to get them on here, don't we?

(20:09 - 20:14)

Frank: Yeah. It would be fascinating. I've seen a couple of their builds.

Yeah, it's a very cool product.

(20:15 - 20:20)

Amelia: And there are other types of concrete you can get too, isn't there? Or am I wrong in saying that?

(20:21 - 20:59)

Frank: Well, like what in particular? What are you thinking? You've got the concrete you can order from your batch plant, the back of a concrete truck.

You've got all these different mixers with colours and stuff you can order with aggregate. It usually comes from a batching plant and there's multiple manufacturers. There's plenty of guys that make it themselves.

Everyone seems a bit lazy compared to, you know, 40 years ago, have the concrete mixer in a barra. Yeah. Yet, I've got to say though, back in, you know, Depression, between the World Wars, people come out, the amount of places I've seen where people mix their own concrete by hand in a barra and they've built the most amazing structures.

(20:59 - 20:59)

Amelia: Oh, yeah.

(21:00 - 21:05)

Frank: Remember a place down the Tamar River here? And there was a jetty and it was all concrete.

(21:06 - 21:06)

Amelia: Oh, that's crazy.

(21:07 - 21:11)

Frank: But it wasn't a little thing. It was huge. But it was all out of the river pebble out of the Tamar.

(21:11 - 21:12)

Amelia: Oh, that would look awesome.

(21:13 - 21:25)

Frank: Well, I suppose it kind of does but it looked really rough. It wasn't well finished. But then we end up working on the house and the house was all built out of concrete, all the walls.

Amelia: Oh, really? 

Frank: Subfloor walls, everything. It was all hand mixed.

Amelia: Really?

(21:25 - 21:25)

Frank: Everything.

(21:26 - 21:37)

Frank: It was all hand mixed. This guy just mixed it by hand. And when you stripped away certain parts, you can see how he poured the concrete in layers.

But it's just one barrow at a time.

(21:38 - 21:38)

Amelia: Oh, man.

(21:38 - 21:44)

Frank: No concrete pumps. Here he is. He would have got the bucket, go up his scaffold, pour it in, vibrate it in.

(21:44 - 21:46)

Amelia: He's probably got a terrible back now.

(21:47 - 21:55)

Frank: Probably built like an ox. 

Amelia: Probably. 

Frank: You know, there was no such thing as a concrete pump, you know, 100 years ago.

(21:55 - 21:56)

Amelia: Yeah, that's true.

(21:57 - 22:00)

Frank: Grab a bucket, grab a shovel, get on with it. You know, they didn't have any money.

(22:01 - 22:01)

Amelia: Yeah, that's true.

(22:01 - 22:04)

Frank: But the sense, the brawn, I'm going to build my house.

(22:04 - 22:07)

Amelia: And it was probably a pretty cheap way of doing it back then.

(22:08 - 22:36)

Frank: Yeah, well, quite possibly. Could be. Yeah. It must have been because I remember when we did this renovation, yeah, because we had to cut holes for the wall and we had to get a concrete cutter in. And it was hard as nails because it was aged quite well.

And it was right next to the Tamar River, so it handled the moisture. Not so much salt on the Tamar River. It was more of an estuary. So, yeah, it handled it quite well. 

Amelia: Yeah, right. 

Frank: Very few cracks in it. It was built like, like I said, a bomb shelter.

(22:37 - 22:38)

Amelia: That's good.

(22:38 - 22:43)

Frank: Yeah, yeah. It was very cool. But all the paths, everything, it's like, oh, done by hand.

(22:43 - 22:44)

Amelia: That's so cool.

(22:45 - 22:54)

Frank: It is. And you find a lot of stuff of that age everywhere, even public works, like council, public works, government, were mixed by hand.

(22:54 - 22:55)

Amelia: Crazy.

(22:55 - 22:56)

Frank: It's just what it was.

(22:56 - 22:57)

Amelia: Not anymore.

(22:57 - 22:57)

Frank: It's what was expected.

(22:58 - 22:58)

Amelia: Not anymore.

(22:58 - 22:59)

Frank: Oh, no.

(22:59 - 23:00)

Amelia: Easy now.

Frank: (23:00 - 23:02)

Oh, no, I can't wheelbarrow that. I've got to get a concrete pump.

(23:02 - 23:07)

Amelia: Oh, look, you've probably got to have 10 certificates for safety and everything now to do it manually.

(23:07 - 23:08)

Frank: Yeah, well, fair point.

(23:09 - 23:17)

Amelia: Yes. All right. So, what are the take-home points for anyone looking to invest in some concrete products on their house, in their house?

(23:18 - 23:51)

Frank: Well, that's, yeah, what's the take-home? Well, you've got to talk to your builder and your expectations of what you want. The most normal thing is, I want this style driveway, footpaths.

I want this polished concrete in my house or burnished. I want to have a concrete bench. I want to have a concrete feature wall, concrete retaining walls, paths, whatever.

There's hoops and hoops of stuff to do out of concrete. You've got to work with the builder, and they're going to find experienced concreters that know how to do this stuff and making sure they understand they're going to meet your requirements because it's very custom, this stuff.

(23:51 - 23:54)

Amelia: Yeah. We might need a concreter to come on the show as well.

(23:55 - 23:57)

Frank: Yeah, true. Someone who's done this stuff.

(23:57 - 23:58)

Amelia: Yeah, yeah.

(23:59 - 24:01)

Frank: But I think the hempcrete one's an interesting one.

(24:01 - 24:05)

Amelia: That is a very interesting one. Stay tuned. We might be able to get someone in on that.

(24:05 - 24:06)

Frank: Yes, definitely.

(24:06 - 24:11)

Amelia: All right. We might wrap it up there, folks. Thanks for listening to the Building Design Primetime Podcast.

(24:11 - 24:11)

Frank: Catch ya’s later.

[OUTRO] (24:20 - 24:24)

You're listening to the Building Design Primetime Podcast.