Browse Forums Owner Builder Forum Re: Pre-cast Concrete House Build Perth 21Oct 08, 2019 11:32 pm Couple of photos of stairs attached.. some more updated photos on instagram - https://www.instagram.com/konkrethaus Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Pre-cast Concrete House Build Perth 22Oct 23, 2019 2:11 pm KonkretHaus amazin.abs @konkretHaus what is the estimated build cost for this build ? Hey @amazin.abs - approximate finished cost of the house, fitout, pool area etc is around $900k-$1M - approximately $2000-2250 per SQM of internal living area over 3 floors. I'm still changing a bunch of things on the fly so wont know exact $$ until its all finished up.Would likely have been move in by now if I didnt make so many changes. ONLY regret so far is not making the Garage Double the size for 4 car garage as it would have been effectively cheaper & faster to do as I could have have manufacuted & installed Basement & GF walls all in 1 hit. (ie same footprint as ground floor so walls would go straight up 2 floors high - similar to the staircase & front of house in one of the early photos) Cost would have been a fair bit higher had I not done plenty of homework & research for about 12+ months. Have got a pretty good contact for Precast here in Perth as a mate that ive known for 20 years owns precast company. For Cabinetry/Fitout I've gone overseas few times to China to inspect few factories so importing all the high cabinetry for kitchens/WIR/Cellar/Garage/bathrooms etc in 2 40FT containers. Also Australian Standard Double Glazed Windows with 7 year warranty as its an AWA Member company which are better than just about any window company I've had a look at in Perth & would have cost more than double locally. Importing NEFF Appliances over from Belgium. algernon - house was initially desigend for double brick and since adapted to concrete. Went with the idea after seeing it on Grand Designs then started researching more into it and fell in love with uniqueness of concrete designs. Have seen more and more concrete houses popping up in Perth now and have had about dozen friends & family interested in exploring the idea so definitely getting more traction! Final product should look like the updated render below. @searching4 knowledge - It is faster than double brick thats for sure, bit slower than I hoped for given the changes I keep making! GF & UF walls will be burnished & sealed white concrete with feature Grey/Black walls so no need for render & texture so that will save plenty of time. That alone will save a tonne of time over the 2 floors, specially with the crane & rigging crew working no matter if its raining or not so in winter time could be difference of few months of time savings Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Hi KonkretHaus, Sorry for jumping on this post for another topic - I'm thinking about buying materials from China as well. Are you happy with the quality of the products you bought? Would you minding sharing the information of the suppliers in China? Thanks Kevin Re: Pre-cast Concrete House Build Perth 23May 17, 2020 9:53 am KonkretHaus Couple of photos of stairs attached.. some more updated photos on instagram - https://www.instagram.com/konkrethaus Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Hi KonkretHaus, Picking up an old thread here. But it's a really nice home. Just wondering if it was difficult converting a double brick design into a concrete one? We're still at deisgn stage but haven't locked in which type of build we want yet.. Thanks Re: Pre-cast Concrete House Build Perth 24Nov 26, 2020 4:01 pm I'm in the design stage also, next to the salt water and looking to use Precast for the majority of our blank walls with steel stud internally, and maybe some kind of precast concrete flooring also. I'm looking to use a sandwich panel for the walls, which is a thin outer concrete, then foam insulating panel, and then the main structural concrete on the inside of the house which gives great insulated internal thermal mass. They use fiberglass connectors to connect the outer concrete and inner concrete together when the pour. https://www.youtube.com/watch?v=r001y_1Y5qc. I spoke to BCG precast in Kwinana and they are happy to try one of the systems ( I couldn't find any companies in west australia that had done this before, they were all very much of the opinion insulation wasn't their department and should be put on after by insulators ) . The benefit of the sandwich panel was less concrete use, and more strength than a single writhe of concrete. Anyone else have any issues with this type of construction , Pro's / Cons ? I am using approx 12 meter high blank walls mostly Re: Pre-cast Concrete House Build Perth 25Nov 26, 2020 4:57 pm Did BGC give you balklpark figure for these panels? Through the roof I would imagine going through them? My guys can get them done also, they are done using structural pins that hold the 2 pieces of concrete together on each side of the XPS insulation. Only thing to be mindful of is not to stack them up on top of each other during transport but to get them sent on A frame so they can be edge lifted Re: Pre-cast Concrete House Build Perth 26Nov 26, 2020 5:05 pm XPS insulation on the outside of the concrete panel is going to be awful. You would need a full blown ERV system as otherwise, you are completely locking all the dampness and water vapour inside, turning such house into a mould pit. Re: Pre-cast Concrete House Build Perth 28Nov 26, 2020 9:30 pm KonkretHaus Did BGC give you balklpark figure for these panels? Through the roof I would imagine going through them? My guys can get them done also, they are done using structural pins that hold the 2 pieces of concrete together on each side of the XPS insulation. Only thing to be mindful of is not to stack them up on top of each other during transport but to get them sent on A frame so they can be edge lifted Yeah - if the structural pins are metal though, then the whole purpose of the XPS is defeated, they need to be non heat conductive pins. Who are your guys also - I'm by no means locked in. BGC were the only people I could find that would entertain the thought of even trying to do it in Wait Awhile. Also how did you do your first floor / second flooring. Is that floating concrete poured on site or did you connect floor joists to the concrete? or something else? Re: Pre-cast Concrete House Build Perth 29Nov 26, 2020 9:37 pm The quote I had for the tilt panel wall - without insulation just a basic tilt panel wall was 160 per square meter. I think BGC said to budget $110 delivered for the precast flooring per sq meter. Don't know about the BCG wall panels - but I priced the connectors at $7000 to cover 100 meters of wall, and the foam was $4000. So all up $11,000 in extra components, expected to use 20-30% less concrete but with more time spent pouring the concrete/laying the ties/foam and finishing the concrete. Re: Pre-cast Concrete House Build Perth 30Nov 26, 2020 10:58 pm dachopper The XPS insulation is in the Center of the concrete... locking all the moisture outside the outer layer of concrete? But also locking moisture/water vapour inside the inner layer? Re: Pre-cast Concrete House Build Perth 31Nov 27, 2020 1:40 am alexp79 dachopper The XPS insulation is in the Center of the concrete... locking all the moisture outside the outer layer of concrete? But also locking moisture/water vapour inside the inner layer? Hi Alex, If you are talking about the latent water that gets released by concrete as is cures? Not much I can do about that - the benefit is that the temperature of the internal concrete should be relatively consistent which will reduce the amount of condensation. We also have a good ventilation plan and live in a moderate wind area which should also help if needed. My research lead me to believe it's one of the best options I can choose to keep the moisture and elements out. I think since it's insulated, you would get more condensation with a gyprock wall than with an insulated concrete panel. Re: Pre-cast Concrete House Build Perth 32Nov 27, 2020 2:10 am Nope, I am talking about water vapours generated inside the house, e.g. bathroom, laundry, kitchen/cooking, breathing, etc. Even when the temperature gradient is not there, vapours will still be eventually turning into the moisture on the backside of your concrete as well as inside internal leaf and eventually corroding reinforcement and damaging the structure. If you will be putting in gyprock on top of your concrete, then a lot of moisture will be accumulating between your concrete and gyprock and gyprock will be eventually rotting. If you are planning to render out, then the render will be falling off. Gyprock + mineral insulation wall, on the other side, is vapour permeable, so the water vapours find they way out as they are easily travelling through the gyprock and mineral insulation and then evaporate through the cavity. Even if they condensate somewhere in the middle, they will easily dry out later. Concrete itself is not very vapour permeable structure (depending on the density, it can be either semi-permeable or not permeable), but XPS has almost zero permeability. You will be completely locking in all the water vapours/moisture inside the structure. Standard ventilation won't be enough, you would need to either go with full blown ERV system which handles ventilation as well as regulates moisture levels or just try living with the windows always open in pretty much all the rooms and esp. south facing ones. Re: Pre-cast Concrete House Build Perth 33Nov 27, 2020 2:47 am alexp79 Nope, I am talking about water vapours generated inside the house, e.g. bathroom, laundry, kitchen/cooking, breathing, etc. Even when the temperature gradient is not there, vapours will still be eventually turning into the moisture on the backside of your concrete as well as inside internal leaf and eventually corroding reinforcement and damaging the structure. If you will be putting in gyprock on top of your concrete, then a lot of moisture will be accumulating between your concrete and gyprock and gyprock will be eventually rotting. If you are planning to render out, then the render will be falling off. Gyprock + mineral insulation wall, on the other side, is vapour permeable, so the water vapours find they way out as they are easily travelling through the gyprock and mineral insulation and then evaporate through the cavity. Even if they condensate somewhere in the middle, they will easily dry out later. Concrete itself is not very vapour permeable structure (depending on the density, it can be either semi-permeable or not permeable), but XPS has almost zero permeability. You will be completely locking in all the water vapours/moisture inside the structure. Standard ventilation won't be enough, you would need to either go with full blown ERV system which handles ventilation as well as regulates moisture levels or just try living with the windows always open in pretty much all the rooms and esp. south facing ones. "Even when the temperature gradient is not there, vapours will still be eventually turning into the moisture on the backside of your concrete as well as inside internal leaf and eventually corroding reinforcement and damaging the structure." Please correct me if I'm wrong, but. My understanding is The benefit of the concrete wall is precisely that the reinforcement is protected from moisture because it is within the concrete. Without the concrete wall it would be exposed ( as cold steel ) directly to the moisture and corrode. The concrete as you say is almost inpermeable and I am very close to the saltwater spray - so trying to pick the best building materials that are going to last the longest. Having said that - we do have a huge amount of windows/ openings / sunlight / skylights in our design, and our Southern wall abuts directly to the neighbours for at least 50%, meaning most of the wall will be protected from the elements. We don't have almost any southern facing windows. Re: Pre-cast Concrete House Build Perth 34Nov 27, 2020 8:08 am dachopper I am very close to the saltwater spray - so trying to pick the best building materials that are going to last the longest. Check out the various codes for marine environmental and maintenance requirements Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Pre-cast Concrete House Build Perth 35Nov 27, 2020 12:14 pm dachopper alexp79 Nope, I am talking about water vapours generated inside the house, e.g. bathroom, laundry, kitchen/cooking, breathing, etc. Even when the temperature gradient is not there, vapours will still be eventually turning into the moisture on the backside of your concrete as well as inside internal leaf and eventually corroding reinforcement and damaging the structure. If you will be putting in gyprock on top of your concrete, then a lot of moisture will be accumulating between your concrete and gyprock and gyprock will be eventually rotting. If you are planning to render out, then the render will be falling off. Gyprock + mineral insulation wall, on the other side, is vapour permeable, so the water vapours find they way out as they are easily travelling through the gyprock and mineral insulation and then evaporate through the cavity. Even if they condensate somewhere in the middle, they will easily dry out later. Concrete itself is not very vapour permeable structure (depending on the density, it can be either semi-permeable or not permeable), but XPS has almost zero permeability. You will be completely locking in all the water vapours/moisture inside the structure. Standard ventilation won't be enough, you would need to either go with full blown ERV system which handles ventilation as well as regulates moisture levels or just try living with the windows always open in pretty much all the rooms and esp. south facing ones. "Even when the temperature gradient is not there, vapours will still be eventually turning into the moisture on the backside of your concrete as well as inside internal leaf and eventually corroding reinforcement and damaging the structure." Please correct me if I'm wrong, but. My understanding is The benefit of the concrete wall is precisely that the reinforcement is protected from moisture because it is within the concrete. Without the concrete wall it would be exposed ( as cold steel ) directly to the moisture and corrode. The concrete as you say is almost inpermeable and I am very close to the saltwater spray - so trying to pick the best building materials that are going to last the longest. Having said that - we do have a huge amount of windows/ openings / sunlight / skylights in our design, and our Southern wall abuts directly to the neighbours for at least 50%, meaning most of the wall will be protected from the elements. We don't have almost any southern facing windows. Concrete is generally waterproofed or protected with render or cladding (when outside) if the want is to protect it from water. It becomes impermeable only at very high densities (e.g. used for massive structures), but I really doubt it is applicable to residential buildings, so in your case it will still likely to be semi-permeable. As I said, I am not worried about elements, I am worried about water vapour from inside the house as it will be creating the main damage. You do not constantly keep all your windows open. Re: Pre-cast Concrete House Build Perth 36Nov 27, 2020 2:55 pm alexp79 dachopper alexp79 Nope, I am talking about water vapours generated inside the house, e.g. bathroom, laundry, kitchen/cooking, breathing, etc. Even when the temperature gradient is not there, vapours will still be eventually turning into the moisture on the backside of your concrete as well as inside internal leaf and eventually corroding reinforcement and damaging the structure. If you will be putting in gyprock on top of your concrete, then a lot of moisture will be accumulating between your concrete and gyprock and gyprock will be eventually rotting. If you are planning to render out, then the render will be falling off. Gyprock + mineral insulation wall, on the other side, is vapour permeable, so the water vapours find they way out as they are easily travelling through the gyprock and mineral insulation and then evaporate through the cavity. Even if they condensate somewhere in the middle, they will easily dry out later. Concrete itself is not very vapour permeable structure (depending on the density, it can be either semi-permeable or not permeable), but XPS has almost zero permeability. You will be completely locking in all the water vapours/moisture inside the structure. Standard ventilation won't be enough, you would need to either go with full blown ERV system which handles ventilation as well as regulates moisture levels or just try living with the windows always open in pretty much all the rooms and esp. south facing ones. "Even when the temperature gradient is not there, vapours will still be eventually turning into the moisture on the backside of your concrete as well as inside internal leaf and eventually corroding reinforcement and damaging the structure." Please correct me if I'm wrong, but. My understanding is The benefit of the concrete wall is precisely that the reinforcement is protected from moisture because it is within the concrete. Without the concrete wall it would be exposed ( as cold steel ) directly to the moisture and corrode. The concrete as you say is almost inpermeable and I am very close to the saltwater spray - so trying to pick the best building materials that are going to last the longest. Having said that - we do have a huge amount of windows/ openings / sunlight / skylights in our design, and our Southern wall abuts directly to the neighbours for at least 50%, meaning most of the wall will be protected from the elements. We don't have almost any southern facing windows. Concrete is generally waterproofed or protected with render or cladding (when outside) if the want is to protect it from water. It becomes impermeable only at very high densities (e.g. used for massive structures), but I really doubt it is applicable to residential buildings, so in your case it will still likely to be semi-permeable. As I said, I am not worried about elements, I am worried about water vapour from inside the house as it will be creating the main damage. You do not constantly keep all your windows open. So, a good recirculating system, or having some external walls that are not concrete would remove the problem you think? Re: Pre-cast Concrete House Build Perth 37Nov 27, 2020 8:09 pm dachopper alexp79 Concrete is generally waterproofed or protected with render or cladding (when outside) if the want is to protect it from water. It becomes impermeable only at very high densities (e.g. used for massive structures), but I really doubt it is applicable to residential buildings, so in your case it will still likely to be semi-permeable. As I said, I am not worried about elements, I am worried about water vapour from inside the house as it will be creating the main damage. You do not constantly keep all your windows open. So, a good recirculating system, or having some external walls that are not concrete would remove the problem you think? Partially the issue can be addressed if you replace XPS with EPS (which is semi-permeable) or mineral insulation (better). But I would still be thinking about installing ERV for the solid walls made of concrete. Re: Pre-cast Concrete House Build Perth 38Nov 28, 2020 11:12 pm alexp79 dachopper alexp79 Concrete is generally waterproofed or protected with render or cladding (when outside) if the want is to protect it from water. It becomes impermeable only at very high densities (e.g. used for massive structures), but I really doubt it is applicable to residential buildings, so in your case it will still likely to be semi-permeable. As I said, I am not worried about elements, I am worried about water vapour from inside the house as it will be creating the main damage. You do not constantly keep all your windows open. So, a good recirculating system, or having some external walls that are not concrete would remove the problem you think? Partially the issue can be addressed if you replace XPS with EPS (which is semi-permeable) or mineral insulation (better). But I would still be thinking about installing ERV for the solid walls made of concrete. That is good to know, from memory, I think EPS foam is an easy option I could change to, because the build is in the spray zone, I had a look an the building codes say we have to use a higher grade concrete, which I am guessing means it is more waterproof. Re: Pre-cast Concrete House Build Perth 39Nov 29, 2020 9:03 am Hey Dachopper Yep without data and proofs you are only guessing BTW, There are a few EPS & Esky Homes built in perth. May I suggest you look to more traditional building materials and get it properly engineered and certified hth Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Ideally you would engage a landscaper to give you some insight what they may need in the space to make your vision come to life… 1 13633 We've had the offer of a short term tenant whilst waiting for CDC/DA home approval and demolition for our knock down rebuild. It would achieve a pretty low rent as it's… 0 13750 |