Transcript
Here is the timestamped transcript, broken down into chapters based on the discussion topics.
Chapter 1: Introduction & Technical Difficulties (00:00 – 01:50)
Matt: G’day, this is Matt Cornell, and I really apologise. We’ve just started our video, and I got 14 minutes in to discover that you couldn’t hear a thing I was saying, and really sorry about that. So, I think we might have another crack. We’re streaming again. It’s a different link, so apologies for that false start, and hopefully, this will work this time.
Matt: So sorry, Sayla! We were doing such a good job, too, but now that we’ve—we were on a roll. Now that we’re really experienced with this, we’ll have another go. So we do have a series of questions. We haven’t received any comments or questions yet, so we’ll go through the questions that we had generated earlier. They’re in that other live link, and I’ll add them to the description of this video, too, after we’ve finished.
Matt: We’ll work through them. It’s about a one-hour cast. Later on, I’ll put the questions in or the time stamps in for the questions, but for now, without further ado, since we’ve had some good practice with the other one without sound, we will cut straight into answering the questions. My name is Matt Cornell, I’m from Cornell Engineers here in Brisbane, Australia, and this is Sayla.
Sayla: Hi!
Matt: She’s a structural engineer, and um, this is actually her last day before she takes some maternity leave, so congratulations, Sayla, we’re very pleased for you. Thanks very much for joining us. I’ll hand over to you, Sayla, and we’ll go start with question one.
Chapter 2: Wall Cracks: What’s Serious? (01:50 – 04:20)
Sayla: Right, so we’ve got 35 questions in total. The first one pertains mostly to worried homeowners. So, these are questions that we get a lot over the phone, usually with a nervous tone behind them. So, first question is: “How do I know if a crack in my wall is serious?”
Sayla: Most of the cracks that we see in homes—specifically wall cracks—are usually around openings such as windows or doors, or along trimmings. So, once again, windows and doors, but also along the tops and bottoms of walls, so maybe where a corner of a corner would come together. These types of cracks are not totally uncommon. How do you know if it’s serious?
Sayla: So, a couple of things: First, we like to refer to Australian Standards, which tell us a lot about if a—there’s a standard actually in AS 2870 that talks a lot about minimum widths of cracks that somebody might look at to understand once they want to take it to the next level. So, 5 millimetres—I’ve understood it to be 5 millimetres—is the maximum width of a crack across the width of a crack that you can measure in a wall, such as plasterboards or finishings, to understand if it’s something that we want to address immediately. So, after 5 millimetres immediately. If it’s less than 5 millimetres, it comes a little bit more down to: Is the crack stabilised, or is it continuing to move?
Sayla: So, you can do this by taking a good record of what the cracks look like to date. So, maybe you step back, take a nice photo, maybe throw a tape measure in there to understand the length and the width of the crack to date. And then you come back and visit it, maybe six months or a year in time, after you’ve seen a couple of seasons, which homes tend to react to. So, humidity, changes in moisture outside, these things all can affect cracks. So, take another visit in six months or a year. If you see a lot of progression in a crack, then maybe it’s time to get a professional, such as a structural engineer, involved.
Matt: The 5mm limit is a Queensland thing, it also comes from Victoria. The Queensland government QBCC only start getting serious when a crack’s wider than 5 millimetres in general, or there’s a series of cracks maybe slightly smaller, but a series of 5 millimetric cracks throughout the home or in a vicinity. And that’s when someone starts—the government, for example, for a new home less than six and a half years—starts getting serious about investigating the damage. If it’s an older home, and the cracks have been there for 20 years, that’s a totally different sort of scenario to something that’s occurred and opened up in the last three to six months. A live crack is something that we’re more likely to investigate or need to investigate than something that cracked 20 years ago, stayed like that until now, and hasn’t changed. Pretty much, if it hasn’t changed at all in the last 20 years, go ahead and get it repaired. Question two.
Chapter 3: Seasonal Movement & Slab Heave (04:20 – 09:30)
Sayla: Number two: “My house has cracks that open in the summer and close after rain. Is that normal?” So, Southeast Queensland, we see a lot of—well, specifically a lot of clay, but other reactive soils that are in the ground that we’re trying to build our homes on and around. These soils react highly to moisture conditions. So, if you have seasonal changes—wet season, dry season—you might see your home reflect that.
Sayla: So, if you’re seeing cracks that open in the summer, it might mean that you’re seeing some swelling in foundational soils due to moisture, and maybe they’re closing as they shrink in the dry seasons. And this is very common, those forces are very strong, they’re strong enough to move your house up and down. Usually, when it comes to damage of that nature, we want to make sure that—I mean, first of all, that your foundational soil around your home and underneath your home is as consistently dry as possible. And there’s lots of sources for water, you know, there’s overland flow during rains, there’s plumbing faults underneath your slab. Maybe you get a plumber involved, run a camera through there, make sure nothing’s damaged. There’s downpipes around your home coming from the roof, make sure that nothing’s cracked or leaking, especially down at the bottom.
Sayla: Another big one is garden beds that run along the side of your home. So, if you have an irrigation system or something that’s designed to add moisture or hold moisture against your footings, we usually recommend to try and remove them or add other precautions to try and keep your foundations dry. So, those are pretty common for seasonal movements and cracks. Is there anything I’m missing?
Matt: No, I think that’s pretty much it. So, say they’re small cracks—well, if they’re seasonal cracks opening and closing, and you aren’t able to manage that by addressing moisture changes or trying to stabilise moisture changes, we do have some tricks up our sleeves for improving the ability of a building to accommodate movement without unsightly cracks. And that generally involves control joints. What people know as brick control joints, or joints in the plasterboard, which are plasterboard control joints. They allow a little bit more flexibility in your home to move unevenly due to foundation movement, summer and winter crack movement, but without causing unsightly cracks. It’s hidden in the control joint, or it’s hidden in the plasterboard control joint. So, that’s your backup plan if the seasonal movement is recurring, and you’ve repaired it, and it keeps coming back. Then there are some plans; there are some ways an engineer can specify control joints to help hide that and make it less obvious, less aesthetic.
Sayla: Where are we, number five? “What is slab heave and is my house at risk?” So, heave, being the raising of the slab, once again usually occurs due to swelling in the foundational soil. So, if you’ve got an upward movement happening in your foundations due to moisture additions, which is causing that swelling, then you might see similar cracks to what we discussed before. So, slab heave damage would look like cracks around, specifically at the corners of openings. If you see vertical cracks at the edge of your foundations, then slab heave is probably considered to be getting maybe a little bit more worrisome. So, beyond that point, then we would probably step in and see what we can do for you.
Matt: Just a reminder that slab heave isn’t always the ground going up, even though it sounds like it is. It could be it’s differential. So, if some part of the house is going down and some’s going up, and some is staying the same, it still looks like one part’s going up relative to the other part. So, keep that in mind.
As engineers, when we go to investigate that, we’re looking for reasons the house is moving, not just why is it lifting. We’re looking for subsidence, uncontrolled fill that hasn’t been compacted properly, piers that haven’t been maybe extended to deep enough soil if it was fill, and the designer was already aware there was soft soil on site. Slope stability: there’s a series of reasons and things that we look for and rule out one by one that could be making the house go down.
Matt: And also, what things could be making the house go up—the other things that we spoke about already, the dog holes beside the house where water ponds next to the footings, obviously a bad thing. Gardens beside the house, not great. Dripping taps, broken pipes, all those sort of things result in slabs going up. And one of our tools is a floor level.
There are videos on our YouTube channel on how we take levels, and how we turn that into a contour plan, and then how we interpret that for addressing specifically slab heave or uneven house movement, and then using that interpretation, what you can do to sort of solve those problems.
Chapter 4: New Construction Cracking (09:30 – 13:30)
Sayla: Where are we, number three. So, also another common question: “Is it normal for a new house to develop small cracks?” So, cracks due to movement that occur during construction or immediately after construction usually have to do with just the weight of a new structure settling into its bones and into its foundation. So, if you’ve got a little bit of movement that you see sort of inconsistently across your home right after a build, specifically up until I think, the five-year point would probably be a good rule of thumb, then that might just be temporary settlement that will stabilise over time, and hopefully, you can sleep at night knowing that will occur.
Sayla: But once you get to that five-year point, maybe beyond that, it might be something a little bit more serious that you want to get an engineer involved. So, if your soils are settling a little bit, usually that has to do with compaction of the soil, how well your builder did putting the site together before he built the foundations, and the design of the footings themselves. So, did your engineer take into account what types of soils are on the lot? Do the footings reach good bearing soil so that that’ll help minimise that downward settlement due to the gravity, the weight of the structure? Yeah, those are the sorts of things we’d like to look at if we see a lot of movement right after construction.
Matt: Don’t forget a lot of builders in that defect liability period, the 12 months after construction, are generally happy to come back and repair a few minor cracks, things that they consider minor, small and minor. They will happily send back a plasterer or a painter because they’re aware these things happen. They’re more than willing to—if you go around with some red dots and mark out some of the damage—some of them, yeah, maybe they won’t; some of them might be, if the damage is too big, then they’re going to refer that to their engineer to have a look at. But the minor stuff, yeah, you might get away with the builder coming back at about the 12-month period, repairing that sort of stuff. If it comes back, then yeah, maybe we’ve got to have a chat.
Sayla: Number four: “My builder says cracking is normal movement. How do I know if they’re right?” So, if you’ve got a good builder who’s done his due diligence and made sure that he’s put together a good product for you, and you know, throughout the construction phase you’ve got other professionals involved to make sure that it’s inspected thoroughly and is built in accordance with the drawings and the design that’s in place for the home, then you know that if it’s been signed off and certified, these things have been checked. Any cracks that you might be seeing might just be that settlement that we were talking about in question three.
Sayla: If we’re talking about a home that’s older—you know, older than that five-year period certainly, but beyond that—then a builder could probably comment quite a lot about what sorts of damage he sees and what’s serious or what isn’t serious, but most good builders will welcome a second opinion. So, if you just have a gut feel that maybe it’s a little more serious and you want to get a second opinion, a structural engineer is your next best call.
Matt: I haven’t got anything to add to that. That’s pretty good.
Chapter 5: Drainage & Foundation Issues (13:30 – 18:20)
Sayla: Number six kind of runs along the same theme. What causes footings to move or settle? So, this is kind of wrapping up everything we’ve talked about in the last five questions, but when you’ve got movement in your footings, there are usually three major things that can cause soil to shift or foundational soils to shift. One was the settlement that occurs immediately after construction, one is the swell and shrink that we’ve talked a little bit about when you add or remove moisture from soil, and the third one is erosion.
Sayla: So, if your footings are being quite literally undermined by soil eroding away, that’s usually storm-related, well that’s when we often see it, is when you see that overland flow, maybe it cuts up against or underneath your footings, then you’ll see erosion, which can—of course, if the footings have nothing to sit on, then they might move.
Matt touched a little bit there on some of the contour plans that lots of engineers, us included, often provide, so we do that by walking around and using a gas level to measure different elevations throughout your slab. When we do that, it’s really nice to have a point-in-time record about how your foundations are doing in one season, maybe retaking the levels and comparing it to another contour plan that we do in another season.
So, that kind of ties together everything that we’ve talked about today. If you suspect that there’s movement or settlement in your footings, we can record the current existing elevations, but we want to make sure that they’re still moving or maybe they’re settled, and that’s how we do that.
We take point-in-time records and then we come back and we do another set of plans at a different season or further on down the road and see if there’s changes, and then we can understand where is moving, how much is moving compared to other areas in the home, and that might help us understand why it’s happening.
Matt: So, that chapter was all about the worried homeowner; we’ve got those six questions under control. Moving on to foundation and drainage, which is another subject that we cover quite a lot on our website and on our YouTube.
Drainage on sloping sites is one of our popular videos, obviously. So, we’ve got a few questions here about sloping blocks and water, and we’ll start with question seven: “We’re on a sloping block and water is getting in. Is this a structural problem or a drainage problem?” Sayla!
Sayla: Well, if you’re on a sloping block, the first thing you want to understand is where the water is coming from. So, if you have—maybe there’s a home further up the block from you that might be directing overland flow into your allotment, that’s quite common for sloping blocks. The other thing is, sometimes with sloping blocks we have water retained around the foundations of our home, sometimes, for example, if you cut and build.
So, if your home is sitting with a retaining wall supporting soil up against your exterior walls, those are common areas where if we’re going to see structural damage or drainage issues that involve entry into your home, that it can get a little bit tricky, and it’s important that they’re constructed correctly.
Sayla: So, back to the question there where we were saying, is it a structural problem or a drainage problem? So, I guess the answer is it could be both. So, if you have a structural retaining wall that is retaining soil outside of your home, obviously it wants to be—it has to be built such that water can’t get in, so the builder will construct the wall, it’ll have waterproof layers, but then there should be a drainage layer behind it that helps direct any moisture that’s maybe underground water or overland flow around your home instead of pooling up against the face of the retaining wall. So, I suppose that’s—
Matt: Yeah, I guess the answer, my two cents is, that it’s both. Water landing or heading towards your home can cause structural issues, and if it’s caused by water, then it should be solved as a drainage issue first. Then, if it can be, the structure can be upgraded or changed later, but it’s going to be cheaper to try and solve it as a drainage issue rather than a structural problem first.
Improve your drainage, find where the water’s coming from, solve those issues, get the water around the house instead of through it, and then we can talk about solving the structural issues if there are any issues left in six months after the ground around your home dries out.
Chapter 6: Soil Classifications & Slab Types (18:20 – 23:00)
Sayla: Right. Number eight, more soil questions. So, this one is: “My soil test said H2—or Class H2, as they say in Australia—what does that mean for my house?” So, H2, your soil tester will give a site classification that talks about how reactive your soils are.
So, we’ve kind of beat this drum a little bit quite a bit during this conversation, we’ve talked about how moisture can affect your foundations, but specifically what type of soil is in the ground and what your house is sitting on, and how reactive it is, is going to talk about how much movement you really need to build your foundations to withstand.
So, you can have slightly reactive soils, you can have moderately reactive soils, or you can have highly reactive, and that’s where that H for H2 comes in. So, if you have H2 soils, that means you have highly reactive soils on your lot, and your footings should be built in accordance with that.
Matt: There’s also a H1. In the old days, previous versions of the Australian Standard AS 2870, there was only a H class site. The latest and maybe the second latest versions of the Australian Standard have separated that high and low region of the highly reactive soils out.
I guess they were getting too many houses being over-designed, too strong, when it only needed to be a little bit stronger than an M class, a moderately reactive soil. So, they’ve divvied that up, made H1 and H2. H2, therefore, means that you’re on the higher end of the H class soil, a little bit more care and attention required for site drainage, a little bit more strength and stiffness required in your footing and slab system.
Sayla: Right. Number nine: “What’s the difference between a waffle slab and a raft slab, and does it matter?” So, waffle slabs—waffle slabs are typically a little bit cheaper to construct, but they do have their demons. So, with a waffle slab, you’re looking at, you know, like a basically a big block that’s filled in with filler blocks, so usually styrofoam or something of that nature, that will give you that sort of classic waffle look. So, it’ll look like strips with your concrete slab poured on top of it. This is usually sits quite high on the ground.
Sayla: I think waffle slabs do sometimes inlet into the ground a little bit, not in the way though that a raft slab would. So, a raft slab is one where we’re actually cutting down into the earth to a depth specified by your engineer to get those strip footings which act as sort of concrete beams, and then your slab—your slab is cast over top of that. So, in this case, your slab would be sitting on soil in between the beams instead of that styrofoam or similar filler. So, that’s the main difference.
Matt: That’s great. On our YouTube, we do have some videos on watching a waffle slab come together, and inspection on a waffle slab inspection where I videoed it and told you what we were looking for, so don’t forget to check that out. We, Cornell Engineers, we don’t design waffle slabs. It’s a long-standing agreement that we’ve had with waffle slabs that we don’t interact with them. We’ll inspect them at construction stage if someone else has designed them, if we need to, but generally, we prefer raft slabs, we think they’re—they might be old school, but in my opinion, anyway, they’re a little bit stronger. I can feel a lot more confidence specifying raft slabs than a waffle slab, it’s just a personal preference. There’s plenty of engineers out there that are happy to do waffle slabs and they’re more than competent and able to certify them, that’s up to them, that’s good.
Chapter 7: Retaining Walls & Timber Rot (23:00 – 28:10)
Sayla: Number ten: “Can retaining walls fail, and how would I know?” So, different types of retaining walls that we see commonly around here is concrete masonry retaining walls, which are made out of cinder blocks with reinforcement inside them. Those are probably the strongest option. There’s also sleeper retaining walls, so that would look like either concrete or timber. Concrete is supported by steel posts intermittently filled with concrete sleepers, or timber posts with timber sleepers.
Sayla: Most of the failures that I’ve seen in my short time has been pertaining to timber sleeper retaining walls, which we see a lot around here, especially in Brisbane. These timber walls, they don’t usually stand too high, usually maybe, you know, 1 to 1.2 metres, sometimes taller, but they’re often used in garden beds or trying to just landscaping elements around your home. And, of course, you might guess that the main issue with them is rot and degradation due to moisture. Specifically, when you see these walls fail, it’s because the posts, or the bottom of the posts where it meets the soil, is usually where you see the damage, and once those posts fail, then the weight of the soil and the water and everything behind it tends to just push the wall forward. In the other types of walls, you know, like if you’ve got a concrete masonry wall that’s on the brink of failure, that would start with warning signs such as cracks—often step cracks, probably between the blocks or vertical cracks. You might see them in the foundations, though those might not be exposed, and the weakest point of the wall is right at the base. So, if you’re going to see something fail, you might see it deflect forward or lean sort of away from the soil face, those are sort of the warning signs that something needs to be done.
Matt: Yeah, as far as investigating, how would you know if the retaining wall is in danger of failing? For timber, you can probe it with a screwdriver. If you can stick a screwdriver all the way through where it should be solid timber, that’s a good sign that the timber’s degraded. It’s time to speak to, if it’s less than a metre, a landscape gardener, or a structural engineer if you need a report on it. They also turn up—the timber retaining walls were used a lot between, along boundary lines in subdivisions, so a lot of the older developments have timber retaining walls on the boundary. We’re investigating a few at the moment and commenting on them. The timber rot, yes, occurs down where the timber’s always wet.
Matt: Timber these days can be specified to be treated for in-ground conditions, it’s a lot different to the timber that might have been used 20 or 30 years ago where it was good solid timber, but it wouldn’t necessarily have been treated for protection against moisture being present against the timber all the time. So, timber retaining walls, even concrete sleeper retaining walls, have a timeline, an end-of-life period, they are different depending on how the wall’s been built, sooner or later, yeah, walls will degrade, and even the steel posts that get buried in the ground, eventually they’re going to corrode and start to get towards end of life.
Matt: So, the trouble is for a lot of these retaining walls, the damage is against the earth on the side where you can’t see it, so it is tricky. That’s why we probe timber, that’s why you might even probe steel, because you need to get into the area where you can’t necessarily see. So, give it a get a skinny screwdriver and go around and try poking it into the timber, and if it disappears, you need to have a chat to a builder or a landscape gardener for replacement, or a structural engineer if it needs a report.
Chapter 8: Older Homes & Structural Risks (28:10 – 32:40)
Sayla: Number eleven: “Do older Queenslanders have particular structural risks?” You know what, these homes are usually pretty well built and have been standing for a long time. They’re usually built using good old hardwood, and often you see them on stumps, so you’ll see them raised, and and that’s obviously helpful for overland flow or some of the drainage issues that we’ve talked about earlier today.
Sayla: Particular structural risks, well, because they are on stumps, one of the big issues that we see with a lot of these old homes is those stumps are often concrete stumps that you’ll see—maybe get infected with a version of concrete cancer or spalling or corrosion of the reinforcement that’s within the stumps. This is really easy to spot underneath your home where you may have storage or you park your car, these stumps are easily visible, so that’s the main issue. Also, because the structure of course is sitting on these stumps that are well-spaced out, if you have one, you know, maybe settle a little bit or raise a little bit, the height differences in your floor might be a little bit obvious. The one thing with these old Queenslanders though is they don’t often have plasterboard walls, we see a lot when we come into them, they’ll have these really forgiving slat walls that allow for a little bit of movement without seeing obvious damage, and nobody wants to look at cracks in their walls, so perhaps they have a little breathing room in that particular area.
Matt: Right up to the minute where you start renovating one of these older Queenslanders, pull all those beautiful slat walls out, make the bathroom bigger, build an ensuite or whatever, and the builder comes in and builds all new plasterboard walls. The risk then is that plasterboard walls are fairly inflexible, intolerant to movement compared to the old style walls. You’ve got a footing system that does move around season to season, and you’ve got an increased risk of things happening to those brand new plasterboard walls. Once again, we’ve got a video about that: “Old Houses Move,” and it happens. You need to be aware if you’re buying an old home or renovating an older home and you’re turning all those flexible walls into inflexible walls, there’s an increased risk that you’re going to get a little bit of movement and cracking in them. It doesn’t necessarily mean the house is falling down or the roof’s falling down, but it is something to be aware of, there’s an increased risk of cracking.
Chapter 9: Renovation vs. Demolition Decisions (32:40 – end)
Sayla: Moving on to a new section here: Buying and Renovating. “What should I look at before buying an older house?” So, older homes, I mean, we’ve got a lot of variations in types of construction that you can come across in older homes. A lot of the time you’ll see an older home that maybe has had some work done to it, so if you want to understand how strong your home is, maybe the first step is: Are you looking at a house that has been maybe renovated or maintained and kept up to date with current standards, or are you looking at a home that’s just sort of been sitting since the day it was built and hasn’t been touched?
Sayla: So, things—I mean, obvious signs- is there obvious cracks in the walls or maybe you see differentiation in the floor, you know, like if there’s a big slope in the floor in the kitchen, you know, what’s going on with that? Is there maybe issues with the foundations, or is it something we need to address, or is it something that’s been there for 20 years, like we’ve talked about earlier today? Other things to look at: If you do have additions added onto the home, it’s nice to know if they’ve been done correctly, so maybe you—
Matt: Are they approved?
Sayla: Yeah, are they approved? And you can obtain all those, especially if they’re recent, those kinds of documents and approvals from the council. And usually, there’s a building and pest involved, that’s a little outside of our scope, but—
Matt: It’s a great place to start, certainly. Structural engineers are really good at solving problems that have already been identified, but for finding the problems in the first place, even my wife and I will use a building and pest inspector to go through a home that we’re considering purchasing because they are experienced, they know what sort of things happen, they’re aware of old-style houses. The reports come with a lot of disclaimers, but the people doing the reports, they’re worth a chat, pull them aside on-site while they’re doing the inspection, ask their opinion, they can tell you a lot more in person than they’re allowed to write down, and um, they’ll point out the things that you might need to be concerned about or you might need further investigation about.
Sayla: On that note: “Do renovations need engineering sign-off?” So, this is usually where your certifier comes in. Usually, they require—especially for major renovations, but even just as something as small as a wall removal—you get it permitted or maybe you don’t, but if you have a certifier involved, they’re going to ask that you have an engineer take a look and sign it off. So, what does that look like? You know, if it’s something as small as a wall removal, maybe we issue just like a detail or a letter or something sort of semi-official that we can—you can point out and say, “Yes, I’ve had an engineer take a look at this, and I’ve done my due diligence, and I’m not affecting the structure as a whole.” For major renovations, of course, obviously, you usually need to have an architect involved or a designer, that’s the first step. The second step is a structural engineer, which can certify the structure, and then your builder has what he needs to do the job in accordance with current standards.
Matt: So, minor stuff that—it also depends on the age of the home. So, an older home, a lot of those internal walls that you’re thinking about removing, opening up between the kitchen and the lounge room, for example, good chance that wall’s load-bearing, it’s carrying part of the roof load, and an engineer is going to specify a roof beam to carry that load to the adjacent walls so that you can do it. It also means that you either get used to having a roof beam there instead of a wall, or you pay a little bit of a surcharge to have that roof beam hidden up in the roof space. If it’s a newer home and it’s an internal wall relocation, if the wall’s a bracing wall, which could be a plywood bracing wall or have strap bracing, then if that bracing wall’s being removed, it also—the bracing needs to be reinstated somewhere else in the house, in the vicinity, in the same line as the bracing wall. So, again, that’s a structural engineer gets involved in that sort of thing.
Matt: So, a lot of the time, we get questions: can we help, can we price, can we have a look at a house, can we tell you if you need engineering for the renovation you’re considering? We are the sort of person to ask, the structural engineer’s the right sort of person to ask that, and also a decent builder if he’s got a set of plans from when the house was built, should be able to tell you if it’s going to affect it. A structural engineer will tell you how to solve it if it’s going to affect the structure, the bracing, or the load-carrying—the things that are holding up and holding down the roof or the floor above.
Sayla: Number sixteen: “What questions should I ask before hiring a builder?” Okay, well, if you’re hiring a builder that’s going to be doing a renovation on your home, obviously you want to make sure that they’ve done—I mean, that they’re certified builders, but beyond that, is he willing to do the work properly, or is he maybe interested in trying to get the job done quickly? But if you have a builder that’s following good plans that’s either provided to you through him or just independently through yourself, then they should have all the tools that they need to do a good job. So, I mean—
Matt: Yeah, that’s fine. Find out about their track record. Speak to people that they’ve built homes for before. Have a look at the Facebook groups, especially some of the larger builders in Australia have pages—Facebook pages dedicated to talking about the quality of workmanship that those builders are producing for them. Find those pages on Facebook and either ask a question or do some reading for yourself.
Matt: Speak to the builder, have some of the answers in your mind already. The research that—the information that is available on YouTube and on websites, and even on artificial intelligence these days, there’s enough information out there that you should have a good idea of what the answers are before you ask them. Ask the builders those questions, see what they say. Be specific: When do inspections get carried out? Who does the inspections? Have an idea of what the answer should be for your area when you ask them, and don’t tell them that you already think you know the answer, and see how they go. See if the information they’re giving you when you ask those questions is logical, if it’s believable, and then verify it later if you have to. Write it down, find out more information so that you can tell whether or not the answer that you got is a good answer or not, and shop around a little bit. Don’t jump into bed with the first builder that says they can build your dream home for half the price that anyone else can, ask the questions, shop around a little bit, it’s worthwhile.
Matt: Insurance and disputes… Number seventeen: “How do storms and hail actually damage a roof structure?” This comes up a lot in our area, I mean, across eastern Australia, I’m sure, but in our area, we see it a lot, you know, just after Christmas, you get this influx of insurance claims that come in, and hail specifically…
Sayla: Hail specifically, hail is a bit of a beast, it can damage the sheathing on top of, you know, like if you’ve got a metal roof, you see quite a bit of hail damage in that sort of nature, and that’s—the problem is that triggers a bit of a trickle-down effect. If you replace, I think it’s more than 20% of your roof sheathing, then suddenly you have to engage a structural engineer and make sure that your roof structure is up to current standards. So, that usually just looks like minor improvements, it usually looks like us upgrading hardware and connections in your roof framing just to make sure that it’s tied down properly to the walls around it, and the independent elements that are in there are all tied together properly. So, that’s what that usually looks like. The other part of this question was storms and hail, so we see a lot of big heavy wind events. When you have wind events on a structure, it behaves in all sorts of ways. If it has the appropriate bracing, then laterally it should be—it should be able to withstand a storm in the area unless it’s beyond what we design for, but the other big one is uplift. So, your home, especially your roof, is going to have outward and inward pressures that occur due to these wind events, and a home that’s been designed for that properly, and in accordance with Australian Standards, should be able to withstand that, but how do they actually damage it? It’s they move it beyond what it’s been designed to do, is the answer to that question.
Matt: So, damage, structural damage is different to the aesthetic damage. A home might move around too much, and there’s cracking in the plasterboard, which is still an insurable event from the storm. It’s still going to maybe result in an insurance claim because we’re talking about insurance now, result in an insurance claim, and generally the plasterboard will get replaced and maybe the home will get stiffened up a little bit at that time. The damage that I think the question that engineers more often look at: Yeah, the roof, part of the roof gets lifted or blown away, or fully translates, in which case the damage looks like there’s parts missing, or there’s holes in the ceiling, or there’s holes in the roof and water’s come in as well as part of the damage—the framing’s damaged, broken, cracked, whatever. Hail damage can look like holes in the roof, hail has damaged roof tiles before, it can go straight through the skylights and non-structural elements of your home. All that comes together when a loss adjuster and a building consultant go through and look at your home. Structural engineers, in particular, get involved when it’s definitely structural damage, the rafters slash or trusses have been affected by the storm or the hail event, and sometimes the storm damage isn’t just from wind, it’s a tree gets knocked blown over and lands on your house. And that obviously causes damage, too, it’s still storm damage, and a structural engineer is going to probably get involved then to help assess the extent of the damage, how much of the building needs to be repaired, and how to do it so the builder’s got a good idea and has a set of drawings or at least some notes on how to reinstate or repair the and remediate the damage.
Sayla: Number eighteen: “How soon after the storm should I get an inspection?” Well, maybe I’ll preface that question just by saying if you—it might make sense to always have a good record of the condition of your home, so maybe if you do a lap before an upcoming storm it might help you understand areas that—you know, after a storm comes through and you see a crack that maybe you didn’t see before, well, are you seeing a crack because a storm has damaged it, or are you seeing a crack because you’re looking for something that maybe you didn’t look for before? Take photos, take videos, absolutely. If you can prove it, the whole process is going to be a lot easier for you to get through to the end with a little bit of help, especially from the insurance side of things. How soon after the storm? Immediately, if you see immediate damage.
Matt: If you can, everyone’s going to be affected by that storm, it’s tough to get consultants and builders to turn up after a storm, a serious storm affects a lot of buildings. Take photos, if you’ve taken the photos beforehand, then yes, you’re very lucky and very wise. If it’s just a set of photos after the storm, get in there, take some photos, if you can, don’t go into a building if it’s unsafe, fly a drone, poke a camera through the window or on a extendable pole or something. Or just stay out of the structure and take photos from the outside, but take some photos, add them to your file, don’t lose them, make sure they’re time-stamped, which they all are these days, digital photos, and and then lodge that claim and pass that information—it might be relevant to the loss adjuster or the insurance company, and if it’s not, you’ve still got it on record, it’s a good thing to have.
Sayla: Which kind of leads to the next question, which is: “How do you determine if damage was pre-existing versus storm-caused?” So, I mean, if you look for it beforehand, then obviously you’ve got your ducks in a row and you know what the condition of your home is before the storm. Most of us don’t think to do that, though. So, how do you determine if it was pre-existing versus storm-caused? Sometimes, I mean, if we get involved with a house that’s got some damage to it and we’re a little bit unclear, things like pictures from your building and pest inspection or maybe realestate.com can be really enlightening. Beyond that—
Matt: Party photos! Everyone is sitting around the house, the kids standing in front of the back wall. Any of those photos, if you’ve got them that show the condition that the wall was in in good nick prior to the insured event, and and can show that now it’s damaged, that helps us a lot. It doesn’t matter if there’s kids in the way, we’ll take those photos, accept them as gospel, and that forms part of our report, it makes it a lot easier. Realestate.com, a lot of people don’t realise, or Street View, if that damage is visible from the street, and Google Street View’s run their camera past there, and we can show—use that to show that there was no damage before the event, there’s damage after the event, then you’ve got a—it’s an easy one for us, we can say definitely show that the damage was caused by a storm, it makes a nice easy report and we can give it the tick for the loss adjuster and the insurance company to keep going with the process.
Sayla: Without that kind of evidence, it can be really hard to prove if something was done during a storm. I mean, there’s some obvious things: If something’s pre-existing and it’s got a, you know, a plant growing through it, well, then it didn’t happen yesterday, but for the most part, it’s really hard to say in black and white.
Sayla: Number twenty: “My insurer rejected my claim. Can an engineer’s report help?” Yeah, if they rejected your claim, they usually have good reason to do so. If you disagree with the reason, then perhaps you get a third party involved. If you have an engineer’s report that says, you know, if you’ve got an RPEQ backing that they they disagree with the insurer’s claim, then then perhaps you’ve got ground to stand on to take next steps, but—
Matt: The reason for the claim rejection matters a lot at this point, and an engineer doesn’t necessarily override an insurance company; we can’t tell insurance companies to accept a claim. Even if the report or the claim and the dispute go to mediation or even AFCA in Queensland, it’s still not a slam dunk that if you get an engineer involved, you’re going to get a good outcome. It really depends on the damage, and structural engineers won’t, for the most part, put their neck out too much; they’ll only say what they can prove, especially if it’s likely to go to court or a tribunal. We want to be able to stand up there and tell the truth, the whole truth, and all that, so it’s important that you can provide evidence, or engineers are looking for evidence just the same as the insurance company was. If there’s been an obvious mistake, then maybe a structural engineer can help point out that mistake, but insurance companies are pretty good at what they do, they look for damage every day, they justify or work out how old the damage is, and structural engineers can’t override insurance necessarily. It’s maybe worth a chat, but it’s definitely not a slam dunk.
Matt: We’ve got a question come in, it says: “Good morning, do you have guidance for how to assess where the line in the sand is when considering either renovating an existing part of a heritage style house versus demolishing?” Well, typically, if the house is character—in a character zone—you don’t have a lot of choice if it you’ve got to at least keep the front facade, and your town planner will tell you how much other than that you’ve got to maintain if it’s a heritage style and it’s in a character overlay. As structural engineers, I have seen reports—they won’t be done by us—that say the house is just so terrible that you can’t maintain it, can’t do anything with it, it’s got to be demolished, not the sort of thing that we’ll do, but I know that there are engineers in Brisbane who’ll write reports like that, that then have to be accepted by council, the town planner, and and council, the people that are making the decisions on whether or not you can demolish it.
Matt: As far as whether or not you should, if it isn’t character overlay and it’s not protected and it’s not on a heritage list or something, I guess it depends on where you’re headed. So, you might be looking—if it’s a renovation, a lot of the stuff, if you’re making changes inside the structure, the old timbers are—if they’re fully termite-eaten or they’re in the wrong place, you’ve got the opportunity to move some of those timbers around. Still going to have to re-support the roof and also that front facade, so there’s that. I guess it depends, case-by-case, is there a line in the sand? No, it involves town planner, council rules, a structural inspection, someone saying whether or not what your ideas are are feasible, a good designer slash architect, and if it’s actually heritage-listed, then a heritage consultant to locate the paperwork for that heritage listing, work out what you can and cannot do to the structure because those rules are way over our head as structural engineers, we’ll have to comply with them, they’re not the sort of thing we can make a decision on. But the renovation, I guess, if you’ve got an older home and it’s not heritage-listed and it’s not in a character overlay, it really comes down to how much work do you need to do to get it to what you want to do? Are you turning a bedroom into a large room, a large lounge room, and most times, for even older homes, really old homes even, we can get away with putting in some beams and some extra bracing, and we don’t specify that the whole house needs to be demolished. The cost comes down to whether or not—or where you’re headed and what your budget is, if you’ve got enough money, you can probably even convince—you can do a full re-gut and re-build, it’s been done before as well. But it, like, it really depends on the budget, where you’re headed, so it’s not an existing line in the sand, we can provide advice, but there’s a few steps before you get a structural engineer involved.
Sayla: You might also find that when it comes to renovations, there’s a more—there’s almost always more hidden costs than you assume there’s going to be at the beginning of a project, you just you never know what you’ll find once you start actually ripping down plasterboard and seeing how things are built, so if you are going to go the renovation route, maybe just giving yourself a little bit of extra leeway in terms of expenses. The demolish and rebuild, just the demo alone, before you go ahead and get all your plans drawn up and do a rebuild, it can be an expensive route to go, but there is the peace of mind of knowing that you’ve got something fresh with no hidden surprises, you can maybe budget for it preemptively, and know more about what you’re going to get into in terms of cost, but that a new structure would be built to current standards, which of course is the best we have so far, and renovating an old structure is trying to improve what’s already there, which may or may not be good, so little bit of risk involved there, yeah.
Matt: My cherry-picked question is: “How do you assess reinforcement in existing concrete without demolishing it?”
Sayla: I just had a phone call about this. Obviously, an engineer showing up on site and looking at a concrete slab doesn’t know what’s necessarily beyond the concrete. And there are a lot of reasons why you might want to look at it if you want to do improvements to a structure, for example, and you need to know if it’s going to be able to—if you can just build on top of it or if you need to improve the foundations. How do you understand what’s in the concrete, specifically reinforcement? So, there’s two things you can do: One is to get the structure scanned, so there’s all sorts of scanning services across Queensland where they basically show up and they scan the concrete and they’re able to put together a little map for you and tell you exactly what’s in there, it can be a little bit vague, but it gives you an understanding on at least if it’s minimally reinforced and what sort of improvements you need. The other thing is, you wouldn’t believe what you can find through the council if you request documents for your home; there’s often—well, especially for newer builds, but for modern construction, there will likely be a paper trail and ideally, a set of engineer’s drawings that can tell you exactly what’s in the ground.
Matt: Yeah, and worst comes to worst, is it such a major structure that it can’t be demolished anyway and started again? But, yeah, the concrete scanners and ground-penetrating radar and their reports- we use them in court; we use them in tribunal; they are reliable enough that we can tell where the reinforcement is, not necessarily how big the bars are, but at least we’ll get an understanding of how deep they are in the concrete and what sort of spacing.
Matt: From our adjusted starting time, we’ve still got about nine minutes to go. If you’re watching and you’ve got a question, you’ve still got like three minutes that you could type something into the comments and and ask your question now, and I guess we’ll cherry-pick out of the 12 questions that we haven’t got to yet.
Matt: On that happy note, that’s our one hour or 59 minutes, which is near enough. I’d like to thank everyone for joining us, really apologise for the and to you, too, Sayla, for the first attempt where we didn’t have any sound, um, thank you very much for joining us, thank hope you got something out of this, and we’ll catch up with you later. Catch you later, bye.
Sayla: Thanks, guys.
Matt: Well done.