New Zealand is OBSESSED! with Concrete Slabs

[@bluewok]

Hey Josh, I'm in my first year at Unitec studying to be a QS. As someone who is moving from a career in hospitality that hasn't got any hands-on experience in the industry, your videos have been an incredible resource to supplement my learning and wrapping my head around how these systems work. I've told everyone in my class to subscribe to your channel. Churr and can't wait for the next vid!

[@joevaiese]

I’d highly suggest if you know a builder ask if you can do a few hours of work with them on a site too. Seeing the process from every angle will give you an awesome perspective, knowledge is power. All the best

[@benjitimu8733]

I studied architecture at Unitec and wish he was around during my studies! So informative

[@dougfinlay7531]

I worked as a QS for 5 years after studying Land Surveying and working in the profession for 18 years. I was taught by my boss who was a builder and the skills/maths required to be a QS were simple compared to Land Surveying/Civil Engineering. I picked it up in a very short time learning from all the builders, our PM and being on site. Concrete slabs were used when the ground was suitable for them as they were quick to establish. Piles were used on more difficult ground. Of course now we use gravel rafts quite a bit under slabs although piles are still used for inadequate ground requiring piles down to solid bearing soil layers. I then started drawing up house designs using Autocad from the knowledge learned over the years in the QS field. I'm now back in the Civil Design and Geotechnical Engineering profession for a greater challenge.

[@peterelliott2914]

I built for 10 years and designed for 20 after that. I still do a bit of both. I love timber floors! I have more control over the process. Timber floors are versatile. The most crazy timber floor I designed was for a dance studio and it was sprung. But timber floors in general are easier on the body whether they're sprung or not and also the thermal mass of conc. is both a blessing and a curse. I'm 65 and thinking about designing and building my last forever home, it'll quite possibly have a timber floor even if it's just floating over a slab.

[@DiscoFang]

Yeah that's the ideal. Natural timber floor spaced up over concrete,

[@nzbuilder]

How cool! You'll have to send me some pictures Id be interested in hearing about if you decide to do it

[@DarkJonas33]

Closer to the ground for more indoor outdoor flow also comes at the cost of less resilience to flooding

[@petercroft9895]

Saw this in CHCH during the quakes - liquifaction literally pouring in the front door in some cases. Everything built here since has the slab well above ground level.

[@f1reguy587]

Flooding is one concern, worst is burst pipework, capillary tracking of water and the huge expense if you want to move a sanitary fixture, all at the expense of structurally weakening the slab from cutting up the steel it used to have.

[@wordzmyth]

Yes flooding is so common now Auckland has a flood viewer map for all Auckland properties. and the nightmare of liquidation which is another kind of flooding. increasing number of house sites now will only be safe if we put them up on legs. Houses in semitropical areas are built raised to withstand groundwater weather events. They have larger gutters and routinely having a storm water retention tank. But we don't seem to be adjusting our building style at all, just making small changes to minimise leaky rooves. And we need our houses to become more flexible as people's needs change, so the huge cost of shifting plumbing as the 2nd commenter say is a big barrier to houses being suitable for changing family types.

[@richardwendt9266]

So, few extra points: 1. Part of the kiwi dream is a 6x6m attached garage. That would require 2 separate systems, concrete and timber floors. 2. With height recession planes as per district plan rules, which are often 2.7m and 28deg from the boundary on your southern boundary (neighbours nothern boundary), timber subfloors around 600mm off ground + 2455mm FFL to U/S of Truss + nowadays a 200mm heal height minimum on the truss to fit enough insulation in, and you're getting to heights above the height recession plane. 3. As a designer, concrete floors are just easier. No bracing calcs, no tables required to work out joist spans, bearer spans and pile sizes. And no cross referencing between the 3 tables to optimize. Just read the geo report, design to suit or pass on to an engineer if SED floor is required for TC2 or TC3. Just from the deisgn perspective, I can lose a day designing a slightly more complex shape timber floor = $$. 1 hour versus 8 hours of work for me. 4. Raft floors (Ribraft etc) don't actually perform that much better than standard NZS3604 floor slabs according to BRANZ and some of the H1 experts for heatloss. Apparently the advantages are negligible.

[@bunning63]

Concrete pumps wow! We were the concrete pump, via a wheelbarrow. A day barrowing concrete and you knew what a hard day's work was.

[@jestnutz]

That's how I got strong. Glad I laboured before studying. Many would give up in the first hour of lifting bags let alone carting full barrows around site.

[@matthewdonoghue321]

There is a famous (in my family) story that my grandfather told me before he died. He and his best mate needed to do some concrete work and they estimated it would take two days. So the first day my grandfather was mixing with the wheelbarrow and his mate was pouring. On the second day they would swap. So the first day came and went and my grandfather was broken... all day lifting and mixing. However when he arrived sore at the site the second day... his mate was standing there with a concrete mixer... with a big grin on his face, a mixer which he had begged borrowed or stolen. My poor grandfather spent all weekend with the short end of the stick.

[@bunning63]

@@matthewdonoghue321 I had forgotten about mixing in a barrow. Worst I did was a fence over a few days, all mixed in the barrow. Last time I checked it was still there, which is amazing in itself. When I got my first mixer there was no stopping me, then I gave myself tennis elbow digging holes in hard ground. The 'Good old days'... Good story about your grandad, must have been speechless when his mate turned up with a mixer, the next day.

[@toranarama1]

Lol, been there done that...

[@bunning63]

@toranarama1 Love being able to say, "back in my day..."

[@noproblem2big337]

I bought a house in Melbourne's east last year that was built in 1971 built by a German surveyor anyway it has a concrete slab with internal heating galvanized air ducts i put a 5m endoscope to check for rust but still in perfect condition 53 years later...beautiful home it even has sisalation aluminium between the brick veneer and stud wall including master bedroom ensuite and courtyard...pretty advanced in those days, but the ductwork in the slab i haven't seen before

[@davehughes9905]

Excellent video - really interesting- thanks for taking the time to make this

[@nzbuilder]

Glad you enjoyed it!

[@Lex-wx3ib]

Great video! Every home owner wanting to renovate should watch this. Explains the two main options perfectly. Thanks from Aus.

[@nzbuilder]

Thanks! Glad you enjoyed it

[@ZachJPG]

Some other positives that get missed for timber floors are also easy to access blocked and broken services (if they are slung under the building) and easier to relevel/ move if they get damaged or need to move. Would love to see more from the CTL Flooring in the future.

[@martiruda]

by the time you access the broken services under the ease to access timber, you will also have a prime sneak peak at the rotting wood and shifted angles.

[@unSTEVOED]

@@martiruda I plumbed my house out with all services under the house. I'd rather come home to a puddle of water under my house that can be easily repaired than a ceiling that has collapsed due to water

[@AnthonyPutter]

Hi Josh, your videos are really great, explaining the residential construction process in an easy-to-understand way.👍

[@nzbuilder]

Thanks for your comment! Means a lot

[@kdowd161]

The great storms of Jan 2023 sent a huge torrent of water under my house - no concrete slab would have been high enough to repel it. As it was, the torrent flowed unimpeded and no damage done. Well done wooden piles....

[@nzbuilder]

Fore sure - they definitely have their place

[@o4pureh2o]

We built a wood floor house on one of very few sloping sections in a new subdivision. Council held up concent for over a year and cost me $30k in interest. We had already built several concrete slap homes in the same subdivision without those issues.

[@fredio54]

On what basis?

[@sportysbusiness]

@@fredio54 Incompetence and bureaucracy. My neighbour has a council issue with his build, the architect had designed the house facing the wrong angle. He wanted to rotate the house by 15 degrees to maximise his view. Because of the local council, it ended up costing him $40,000 in engineering, council and additional bank fees and delayed the build by 18 months. In those 18 months, building costs have increased by over 20%...

[@Satrazzi]

Thank you for this video! Coming from Canada and living in New Zealand the different building materials always stump me. In Canada we typically do a cinderblock basement with a concrete slab poor, and then metal/wood poles to hold up the first floor. I'd love to see some basements (below ground) houses/builds in New Zealand!

[@lagosite]

Mostly concrete here in the Philippines as well. Timber costs are high here and I am not aware of any codes which require identifying timber grades for different applications - so most people use concrete nowadays.

[@DiscoFang]

Very good point about elephant feet. After years of living in timber buildings in Wellington I DREEEAAMM of living in a full concrete build. Floors AND walls.

[@nzbuilder]

Agree - concrete slabs are much quieter

[@BigFourHead]

yea i dont, cold floors are not fun to deal with. new builds have concrete floors and hate it!

[@weehudyy]

The reason Welly has so many timber buildings is that it is right on a fault line . Concrete, bricks and mortar do not deal well with earth tremors as Christchurch demonstrated graphically .

[@weehudyy]

@@nzbuilder Right up until that first earth tremor ...

[@BigFourHead]

@@weehudyy so all the new builds in upper hutt (and there are a lot of them) are doomed?

[@BoldRam]

Great video Josh. Really informative and easy to understand. I think you're right that wood laminates may be favoured a bit more soon too.

[@colinfox6961]

The main reason for building with concrete pads in NZ is to be able to build closer to the boundaries with lower shadowlines, thus using less land area. Would never buy a house in NZ unless on piles myself, only have to look at results from the aftermath of Christchurch earthquake right offs.

[@thesmorgasbord6457]

im an engineer from canada working here in nz now. its crazy to see the differences in home building. have you considered a 50mm concrete topping on top of your wood floors? this is a common detail for decades now in north america. it gives you the benefit of concrete floors as well as the wood subfloor. you can even put hydronic tubes in the concrete topping for in floor heating. also, the main difference is that here in NZ i guess the main foundation for homes is either slab on grade or piles; while the standard way to build in canada is with concrete footings where you place concrete strips in the load bearing locations such as your outside walls, interior load bearing walls, and then put floor joists on the footings. basically minimizing the concrete used while maximizing the wood used, for a variety of benefits.

[@trevorgrenon9162]

How have topping slabs (over timber substrates) performed in earthqauakes?

[@thesmorgasbord6457]

@@trevorgrenon9162 trivial amount of deadload added to the floor plates which is accounted for in the shear walls because we use plywood sheathing on the buildings which is another big difference. Rabbit hole goes quite deep...

[@DiscoFang]

Concrete over timber in New Zealand? You did hear the bit about earthquakes didn't you?

[@pulporock]

I'm in Oz, it's done but its difficult to get the trades to do topping slabs. Its a really worthwhile option to consider.

[@ytzpilot]

Concrete over Timber is used in Commercial Properties in New Zealand, I have leased two commercial properties in Wellington one building was from the late 70s and the other was early 80s and both have timber with concrete poured on top, something I have never seen in Canada. My current property is on the 6th floor of a 12 story building in Wellington and does not have a sprinkler system in our unit, even though the ceiling in our unit is timber, something completely unheard of in Canada as well.

[@GimbloBlimfby]

I want to see a CLT build. That looks like a neat idea.

[@Sikasays]

The new Auckland City Mission is a CLT building.. not sure if theres any videos on it floating around though

[@EinBein13]

Similar problems to conventional timber: poor acoustic performance. In Europe, they apply a concrete topping on the CLT to reduce that (screed).

[@nzbuilder]

Totally! Looking forward to CLT builds becoming more common

[@janineclarkson3991]

I very much liked your post on the ‘granny flat’ law change, you hit many of my questions particularly earthquake resistance and weetbix particle build, would love to hear more of your thoughts on maxraft and anything on new building materials/passivhaus. Great content 10/10 would recommend 🤗

[@remiewatkins8032]

Thanks Josh love your video I have been out of building for 30 years lots of stuff is deferent great job

[@nzbuilder]

Thanks very much - means a lot from someone who's been around the industry for that long

[@shamoolie]

I didn't think this video would be that interesting to me but I was pleasantly surprised. I like how you keep it simple, 1 more sub.

[@nzbuilder]

Glad to hear it!

[@jeremybrowne9221]

Just discovered your videos. Quality content.

[@francescabellbooth5432]

amazing work, very helpful video content!

[@Volkaer]

I've put in a concrete slab, and timber floor over the top of it just to subvert expectations :P It'd definitely say that it's not "faster" though (at least in the little experience I've had) - you have to tie in putting the slab in with the sparky, plumber, drainlayer if different guy than the plumber doing your septic tank and whatnot - and everyone's always busy and will be there next week. Timber piles, you just build everything first and whoever needs to do anything can do it later on and go through the floor. You can also take your time building on a concrete slab if you're waiting on materials and whatnot (ie. you're not a big building company builder that can dictate when and what happens using their own warehouses, tradies, transport, materials etc.)

[@hematiteolsen8762]

Great videos Josh. Keep them coming!

[@nzbuilder]

thanks!

[@fredio54]

I'm doing a small cabin, it's getting a slab, but a fully insulated slab with high thermal mass.... it will be cut into the hillside, and the removed material will build up in front of it to keep the deck to drop off height under consent limits. There will be another floor above the slab with heating in it, and all the valuable solar gear that prefers cool stable temps in that engineering layer. Safe from theft and out of the way.

[@BogdanHmelnitchii]

Привет Джош, ты просто молодец!!! Ты вдохновляешь людей жить красиво!

[@somerandomgoogleuser3374]

As a Kiwi indentured builder of 37 years, timber floors are much much nicer to walk on.... They have that "little bit of give" in them & you can feel it & appreciate it. "Stompping Elephant Syndrome" is a "user interface problem"...... i.e. the a hole doing it. Also most concrete slabs are constructed too low too the ground here in N.Z. & don't actually meet the 3604 code but council inspectors are so useless they never pick up on it or don't care..... Seen it happen for many many years...... Virtually all concrete slabs never get "curred properly" or adequately in here in N.Z. as well, as it's all rush rush now days. Concrete takes 28 days to cure fully & needs to be kept wet so the cement can keep hydrating itself in the curing process..... Virtually all concrete here is just poured & not cured at all & un cured concrete doesn't atain half of it's possible strength. Who invented concrete?? It'll supprise you how long ago it was invented!!! .... Those clever bastards!!! They changed the world....

[@lockk132]

Romans

[@wheresthedeli8822]

aliens

[@DiscoFang]

Aquaman and the fish. All those shells cluttering up the seabed were useful for something. Atlantis was all slab on grade.

[@gustonzimasheen]

13:14: I used to live in a multi-storey hostel where the floors/ceiling were constructed of wood. I can totally relate to "elephants stomping across the floor" sounds. I lived on the ground floor which was a concrete slab so I was ok and not bothering anyone. I feel like the noise from the upstairs neighbours could have been mitigated with a layer of insulation and sound dampening material, but the owners went with the cheapest option I'm sure. LOL. There were countless other problems with that building, as it was a leaky building, where they installed the wrong rated pipes for water connecting all the hydronic wall heaters/radiators. Think it was PVC in some places?

[@martiruda]

we built a two story house, concrete slab in both levels. nothing beats it!

[@gustonzimasheen]

@@martiruda That sounds awesome (well no sounds I hope).

[@martiruda]

@@gustonzimasheen literally xD

[@georgeferns6482]

Hi Josh. I moved to nz 16 years ago. In South Africa. All houses without exception there are built with a concrete slab and brick and mortar for internal and external walls. Found it quite hard to get used to posts, timber floors and drywall.

[@nzbuilder]

Very interesting how every country has their standard

[@Rich_1]

I'm not a builder, but I still find this so interesting. I live in a 100-year-old house built on a hardwood timber frame with concrete piles, and it's definitely not square at all!

[@paulhoogeveen7353]

Was it even built square from the start? (No... 😂)

[@KiwiMaker]

They both have pros and cons. I feel a well insulated wooden floor can be warmer and ALOT easier to deal with future plumbing issues/ Renos.

[@nzbuilder]

For sure - both have their place

[@socks2441]

my parents house is old, very old. it has the wooden floor raised by wooden foundations. its handy to have under house storage too. not that its pleasant or roomy crawling around down there. no wonder houses are flooding these days if none of them are raised.

[@thekiwinomad]

Interesting video. I know where I live a lot of them are still wooden floors on piles. I understand that's there's an increase in costs vs concrete slabs. But as it's an earthquake pourn area where most site are hill sides and flooding and drainage can be an issue. A wooden floor with piles makes more sense rather than the amount of work it'll take to do the cut and fills required

[@Justyburger]

Good video. We've gone through a number of design processes and the last one, we were going to use SIPS panels, which were two layers of Magnesium board with polystyrene in the middle. Mag board is very hardy and water resistant. We were also going to use Espan CLT products for our floors. In the end, that project blew budget and we cancelled it. We are still left wondering what to do. In central New Plymouth, the Council is now allowing house building heights of 11m, which allows 3 floors, so we might build a compact tall Air B&B? Our issue is also having a very soft ground, so we have to pile down deep and probably have a steel structure if we go 3 floors high. But....National have been talking about a non consent 60sqm granny flat option, so that's a possibility too.

[@myladysigyn]

I've been watching a house across the road from me being built. It used to have an old Petone workers house. They gutted out the asbestos before demoing the place in one day (which was fun to watch i gotta say). They then spent several weeks digging up the ground by several feet before leveling it all off to road level (not sure what they did there but maybe something to do with ancient pipe work). They did the concrete slab just like you showed in this video (which is why i watched it as i was real curious). It appears they will be building multi story apartments on the site now. thanks for the video, im not a tradie, just interested.

[@nzbuilder]

Building is an amazing thing to watch - glad your enjoying the content

[@BramBiesiekierski]

Concrete and brick is by far the best common construction technique we have these days. You can build a house with concrete slab and brick walls. And in 100 years its still going be as strong and look the same as it did the day it was built. Timber (especially plantation pine etc) will rot or fall apart well before then. And its not even striaght when its new, let alone years down the road. My house is a 60s double brick house. It has jarrah timber frame flooring. Cement tiles on pitched jarrah roof framing. The bricks are just as good as when they were layed. The timber though is sagging and squeeking. I had replaced all external fascias, gutters and eves because they have rotten away. But the bricks are still going strong

[@nzbuilder]

How good! huge benefit of a brick home is the maintenance

[@tealkerberus748]

Concrete's alright - the only reason concrete rates so high in total CO2 emissions worldwide is because we use so much of it. If we built to last, that wouldn't be a problem - and even as it stands, trying to replace the concrete we use with steel or aluminium would emit vastly more CO2, and there simply aren't enough trees in the world to replace concrete with timber. But a concrete slab or concrete building should be engineered to last several hundred years, and when we're finished with it we can crush it up and use it in the next structure. Use concrete *thinkingly* and it's not a problem. But all that polystyrene? That's a hard nope. Poisonous as it stands, flammable with truly disastrous smoke, and functionally impossible to reuse or recycle. The planet deserves better than that we contaminate our dwellings with that muck.

[@paulhoogeveen7353]

Concrete tends to have a few issues with earthquakes and the fact that on the shaky isles is on fault lines and volcanoes means odds are in a major event (like the Christchurch earthquakes) a lot of buildings are going to suffer major damage and be condemned. "Option C" go base isolating.

[@GerryThompson-x8c]

Great video but could have mentioned alternatives for timber floors such as concrete perimeter foundation walls and t&g flooring

[@glennimmortal]

Great video, I personally prefer timber subfloors, I would add that timber subfloors are great if you're a one man band. We have had rib raft slabs Completed with frames on site in 7 days when the site is straight forward, they are amazing when done right.

[@nzbuilder]

Totally agree - built many great homes on sub-floors

[@pinkyfull]

As someone currently living in a timber floor from the 50's (Matai to be specific), who just upgraded the insulation, i can attest that Wooden flooring is a preference for me now. having a sub-floor that i can get into is very useful for any renovation works, and we've done many. I also think that the Concrete methodology is not great from a thermal sense, its a thermal bridge, and to create a true passive house on a concrete slab you need to thermally elevate the building off the foundation slab, but with none of the advantages of a sub-floor space to move around in.

[@rickhanover6267]

Sorry timber floor every time. Remedial action is possible if there is land movement, and go for plywood for strength and durability, in the presence of moisture or leaking services especially if undetected over time. The number of concrete houses that were demolished compared to timber construction of dwellings in the Christchurch quake, is testament to that. A wood floor can often be warmer with insulation, and don't use polystyrene, as even with fire retardant it is still flammable and in a fire produces lethal toxic smoke. Subsequent additions of rooms etc is cheaper, especially if the house positioning on a site may mean limited access when building. Plumbing and electrics are accessible with timber structure and floors, re-wires or new wiring can be easily installed. A wool carpet with underlay may be all that is needed to provide floor insulation in warmer parts of the country. Additionally floor slabs may result in a level of dampness in high rainfall locations especially on sloping sections where waterproof membranes can fail and drainage is insufficient, and where retaining walls are present. An elevated wood floor generally allows good ventilation under the floor

[@blusheen378]

Good that you show the other merits of timber floors. House with timber floor, if you have a HRV and a heat pump, you will find moisture and heat is well controlled through the year. Also virtually absence of condensation/crying windows on glass. Own and live in either types, you will tell the difference. Water leaks in concrete slab houses, How to repair? Piping in ceiling, like in Aus?

[@somerandomgoogleuser3374]

I agree 💯 % as a Kiwi born chippie of 37 years in the trade - finally somebody else with great knowledge too,!!!! An "extreme rarity" now days!! Bit like the "N.Z. born Kiwi"......😮

[@nzbuilder]

Definitely pros and cons to both

[@wassim9763]

you will always need underfloor insulation in a suspended timber floor. carpet and underlay wouldn't suffice unless there's a high R rated underlay, haven't seen it used.

[@ChristoKiwi]

What about rising damp? My 70s home has a concrete slab in the garage and rumpus room areas and the waterproof membrane has failed in multiple areas with water slowly rising up. To replace it will cost well over $100k... Are concrete slabs these days somehow more waterproof?

[@SM-sl9dy]

Hi Josh, could you talk more about earthquake-proof building some time in a video (or how damage can be minimised)?

[@ronnymcdonald2543]

Live in a single story timber home and no brick chimney and yr pretty bullet proof from any earthquake.

[@paulhoogeveen7353]

BASE ISOLATING!!!

[@BenZolno]

Great stuff. Please also cover the environmental impact of the method/materials next time.

[@nzbuilder]

For sure! Watch this space

[@citation51power]

I just wish builders would use 290mm joists instead of 240. You should never be able to hear stomping throughout the building or hear ratting furniture caused by joist deflection, the mid floor in my 1970s building suffers from this and I have been battling with it for years, I have doubled up many of the joists added more blocking extra screws in the particle board decking and put steel strapping under the joist blocking, this actually made the most improvement but my next move will be to install steel beams. But to my surprise, many brand new buildings have the exact same problem, I'm not a heavy dude either, just 80kg and walk light on my feet with shoes off to avoid floor deflection. But whoever engineers these buildings, they seriously need to up their game.

[@jonplayle6954]

I've been a concreter for 27 year's and in my opinion it's the easiest and fastest way to get a whare started especially if you want underfloor heating

[@nzbuilder]

Great for sound deadening as well

[@andy3341]

Great overview, thank you. I presume timber floors/construction would also allow for easier wholesale house relocation and reuse, more so than concrete. I'm thinking flood prone areas or infill relocation and retro-fit type scenarios. Concrete has its place, but probably should be used as a last resort material, as it has a high carbon/energy footprint.

[@nzbuilder]

Totally - both have their pros and cons. Check out some of my other slab videos to see how they actually work and the amount of engineering that goes in to each one.

[@angelawest9759]

I would not want to live in a multi story wooden building. I live in a neighbourhood of old bungalows and I can always hear the neighbours stomping around. Block of flats would be terrible. Great vid.

[@jackhew93]

Thanks for the video. Wooden floors sound more flexible in every way. I remember a house with concrete floor on the westcoast sinking It was a nightmare to fix. What about a brick floor if thats a thing

[@mareeshotter2557]

I n the last year i stared with a concerte company in np was driving for a year and iam now batching,good to no this will help with my batching apprenticeship

[@nzbuilder]

Awesome - I'm glad!

[@mattgthor]

I used to do slabs 15-20 years ago. With a crew of 4, we could box a 200m2 floor in 2-3 days. Another day for pour and one more for de-box a week or so later. Some quicker some slower. Slabs from 40m2 to 500m2. All depends on the good ground. Since then, I've been a QS and most floors are SED and not 3604 or firth ribraft. Edit... slabs are only good on flat sites, que massive earthworks and retaining/drainage

[@Sub0x-x40]

might move to nz coz they go the mad slabs

[@jiripeconka4494]

I am no eco-maniac but it would be fair to add concrete also has a massive carbon cost when making it. There are carbon lighter variants of it but the price advantage gets hurt that way...

[@nzbuilder]

This would make a great video - thanks for the comment!

[@NeedsmoreCowbell72]

Timber all the way. I have owned 2 houses with concrete floors, hated them with a passion! Why? If you have any services go wrong you will be paying at least $10,000 to have them repaired. The drain from our kitchen sink broke and blocked. The pipe was 12.5 mtrs long. If our house was on piles, it would have cost less than $500 and I could do it myself. Being a concrete floor we had to take out the kitchen cabinets, strip the laundry and bathroom and then have a concrete cutter in our house cutting up the floor before the plumber did his job and then new concrete, wait 10 days, then reassemble kitchen etc. In 2004 it cost us $15,700 + my time with the kitchen etc. And guess what, insurance won't cover that as it's classed as 'gradual damage'. As far as I'm concerned you can shove a concrete floor where the Pope fears to wash!

[@nzbuilder]

Definitely great reasons to do piles!

[@floatsomboy]

You missed a few things that a timber sub floor can be relocated easily and access to services under the floor is really easy; and should you need to move something later on down the track this can be done easily . Con floor can rot if allowed to get wet /have a leak. I would take a timber sub floor any day on screw piles

[@nzbuilder]

Very good points!

[@bradynixon8900]

I’ve had houses with both timber and concrete that my wife and I hsve added to ourselves over time, selling on for large profits. My current house is 8 years old with a rib raft slab and it’s turning out to be bit of a problem to add too because of differential settlement that can’t easily be remedied. The original slab and the new slab cannot be structurally joined with sufficient steel to ensure they work together and the structural engineer advises that there will always be a risk of differential settlement and a 44mm movement at the roof level is probable. Which raises the prospect of a leaking roof. Painfully penetrations for new bathrooms in the original slab are not really that easy to deal with, if at all possible. Whilst I prefer concrete the fact is active raft solution is shit for renovations and additions.

[@toranarama1]

Don't get rats living in your concrete slab

[@harrywp5785]

Josh, far better than chip board rubbish. Mother in laws home needs entire new floor. Built in 70's. Its chip sheet and dissintegrating. $$$$$$

[@grahamb701]

My NZ house was built in the '60s with a concrete slab. NOT insulated so the 'thermal mass' sucks up heat all winter!

[@nzbuilder]

Interesting isn't it - the slab edge insulation that we are seeing more and more now fixes that issue

[@grahamb701]

@@nzbuilder So much better these days!

[@LisenbourgPotato]

Like the video says, how easily do concrete slabs get damaged by earthquakes? If I build in more earthquake-prone regions, is it safer to use timber rather than concrete? Appreciate any response.

[@WriteTrax]

It's a real slab in the face when you notice it

[@brettcrawford8878]

10 mm mesh makes a stronger slab with fewer cracks. Is better to tie the slab to the ground with ratwalls or trench with steel reinforced concrete and steel reinforcing rods or bars to tie them to the concrete slab. A lot more builders just sit the slab on the ground with nothing tieing it into the ground these days. Always best to vibrate all the concrete to increase its strength. 😊

[@moretriflenowplz1837]

If you mixed GP and fly ash would you get a stronger base?

[@MrWildabeats]

Screw piles have quickened up the timber floor process..

[@nzbuilder]

They are a great option

[@BTee1980]

We build transportables on tanalized subfloor with 24mm ply.. i hate concrete

[@76insider]

Following my experience after the CHCH earthquakes, I wouldn't ever do a slab floor build. Easier access with piles, easier to make changes, repair plumbing etc.

[@Pete856]

The CHCH earthquakes showed soil types need to be considered when building. Anything built on soft sandy soils needs to have piles as it's more likely to survive if there's liquefaction. However, houses built on solid clay soils have no issues with liquefaction, so a concrete slab is fine....but your other points are good ones too.

[@nzbuilder]

For sure - I think engineers are pretty on to it with the design of each foundation these days as well

[@ezekielchariot]

I think NZ is, because AU is, because the USA is. We didn't do much on our own without trends elsewhere first.

[@kenbaird7067]

Our houses in Christchurch all had piled foundations. Our house we occupied during the Christchurch earthquake suffered NO foundation damage as did our previous 3 houses. Two of our friends with new houses, less than 1year old, which were destroyed and red stickered by the failure of their concrete floors. All areas of NZ are earthquake probe, hence the preferred use of concrete seems to me, as an engineer, rather illogical.

[@TheKodiak72]

Basically every house in Australia is also on a concrete slab.. Its not even that weird....

[@nzbuilder]

Very much the standard here too

[@CaptinCrofty]

7:36 that was scary bro

[@mikewilliams6086]

Kiwis arent obsessed its driven by the big industry companies like Fletchers. Also newer houses are much warmer and consistent temperature. Also its a strong foundation.

[@andysbatten]

No mention of ground conditions - weight bearing capacity etc and which option of foundation is better?

[@nzbuilder]

Check out some of my other videos on foundations - hopefully they have the answers otherwise flick me a message and ill create more content around this

[@weehudyy]

The Christchurch 'quake revealed the inherent flaw in the concrete slab ... Wood flexes

[@RichardGeresGerbil]

I prefer timber because later editions are infinitely easier to install, like plumbing or wiring under house access is underrated. Also i don't understand the flat area thing he brought up the point of a foundation is to create a flat area timber or concrete

[@korakys]

Living in earthquake country I'd never choose concrete if I had the option, the long term maintenance is going to end up costing more than timbre.

[@nzbuilder]

Definitely not the case - engineers design all of our slabs to adhere to NZ requirements.

[@jamess1787]

I love eating kiwis. Yum. 🥝

[@markkennard861]

I'm a Kiwi.. don't eat me :) they are known as kiwifruit here..

[@napalmarsch]

do some houses build an underground basement or always all over ground?

[@darrynyee8674]

Basements for residential houses are extremely uncommon in New Zealand.

[@incredifall]

Nice!

[@psidvicious]

“Elephant feet” can be especially annoying if the ones stomping around upstairs are not your own children and they’re a completely separate resident. 😖

[@laurentreti5972]

Thats why we got no big old trees

[@shoutatthesky]

So to sum it up - timber is better but concrete is cheaper.

[@JedRichards]

Not a builder but it makes me sad to see so much concrete, plastic, metal and other shit buried into the ground. On that basis alone, timber subfloors on piles seems like it treads more lightly on the earth

[@fredio54]

There is a building ceiling and putting the first floor close to the ground is the ONLY option if you want generous 2 or tight 3 inside that limit. Plus thermal mass is key to comfort with careless undisciplined occupants and or allowing yourself to relax and be more care free with doors being open longer etc.

[@ScuzzySera]

The styrofoam blocking is wild.

[@BobMcVicar-t7k]

@@ScuzzySeraand I e seen so much broken and chips of styrofoam blowing all over building sites - eco disaster

[@KiwiMaker]

@@BobMcVicar-t7k Theres a new build near my house and on windy days the street gutters are filled with those little styrofoam balls...

[@TheMntnG]

why does NZ not do basement foundations like europe?!

[@jack80kiwi]

Lower to the ground , easier to flood as has been proved many times.

[@HalfLapJoint]

The biggest downfall of concrete slabs is their CO2 emissions, whereas timber floors sequester CO2. One advantage missed for timber floors: flood protection

[@nzbuilder]

Thanks for the comment - Definitely something to look in to

[@f1reguy587]

Nz loves concrete because you dont need a license to do it… and we know how much the guys that do this type of work love having no license and no real risk since its engineered by someone else.

[@anthonyvizzo1456]

What does a person have to do to get a legit garage access basement in NZ?

[@nzbuilder]

Just ask their designer to put it in the plan :)

[@anthonyvizzo1456]

@@nzbuilder Haha I guess if you are building! Was mostly a comment about having seen none thus far around auckland! I thought there might be a technical reason (the clay or something) but I guess it's a cultural thing!

[@scorpiuswireless1]

95% of Aussie homes were concrete slabs by 1990. NZ plays catch up

[@DossNZ]

There will be more and more flooding in our concrete gardens.

[@tristanpatterson3843]

Binding sand?

[@Justnuts-d9b]

The sand provides a barrier between the damp proof membrane and the hardfill

[@tristanpatterson3843]

@@Justnuts-d9b Yeah, it's called blinding sand.

[@tristanpatterson3843]

He probably thinks it's sand that binds together, lol.

[@Justnuts-d9b]

@@tristanpatterson3843 builder of 25 year here i kind of know what it is

[@DiscoFang]

Common mistake. For some reason malapropisms abound in New Zealand. it doensn't help that binding sand is actually a thing we use too in landscaping.

[@PaulG.x]

It's all fun and games until you get flooded and all that buoyant foam lifts the slab off the ground and causes it to crack into pieces

[@whaioraproductions]

i blame the peanut slab

[@giovannip.1433]

How do you stop rodents undermining your concrete and insulation? What kinds of concrete slabs can be put on piles - without having to dig out and stabilize areas? What is becoming more common is composite steel floors like 'container homes - so foundations are key, concrete, wood or steel? Can you use a variety of foundations within the same build?

[@DiscoFang]

What rodents are you talking about? In New Zealand.

[@giovannip.1433]

​@@DiscoFangRats, mice not normally rabbits - burrowing animals.

[@rafadacosta1675]

Hey Josh, have you ever thought about doing more hands-on videos?

[@nzbuilder]

Love getting on site and being on the tools - but any business owner knows there's a lot to be done in the office. Ill take your feedback onboard though - watch this space!

[@gregj7916]

interesting... concrete & supposedly clean green new zealand...

[@DiscoFang]

Who ever said NZ is clean green?

[@gregj7916]

@@DiscoFang tourist advertising many years ago.

[@DiscoFang]

@@gregj7916I think that was 25 years ago, right? ”Just because the rose dies on the vine doesn’t mean it lied to you when it was in bloom.” But anyway, to the facts, here in NZ 82% of electricty production is from renewables. That is, not producing CO2. We also do not have a water shortage. So what’s the problem with concrete produced here?

[@petercroft9895]

​@@DiscoFangconcrete production releases insane amounts of CO2, and is extremely energy intensive. If you ever get the chance to visit a cement mill, it's quite an eye opener - concrete's dirty little secret.

[@DiscoFang]

⁠​⁠​⁠@@petercroft9895A typical passenger vehicle emits 4.5 tons of C02 in a year. Foundation concrete in a house typically embodies 250kg of C02 so a 150sqm house foundation that will last 100+years has around the same C02 footprint as one year of driving the car that lives in that house. Misguided and misdirected snide criticism.

[@KiwiTimmy]

I hate my concrete foundation :(

[@WigneyR]

NZ just learning about concrete is interesting, considering every concrete crew I’ve seen in AUS is kiwi 😂