Browse Forums Building A New House Re: Building a flame zone house in West Pymble on a steep si 22Aug 30, 2023 3:07 pm Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 23Aug 31, 2023 4:28 am Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 24Sep 02, 2023 10:55 am Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 26Sep 02, 2023 1:43 pm Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 27Sep 05, 2023 6:11 am Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 29Sep 05, 2023 2:13 pm Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 30Sep 08, 2023 9:27 am Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 31Sep 19, 2023 11:18 am Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 32Sep 22, 2023 2:15 pm Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 33Sep 22, 2023 2:24 pm Why soil, not sand? You would generally do not want to have reactive soil under the slab. Also, compaction with excavator is never enough. I believe the main reliance is on the piers now. Re: Building a flame zone house in West Pymble on a steep si 34Sep 22, 2023 3:37 pm alexp79 Why soil, not sand? You would generally do not want to have reactive soil under the slab. Also, compaction with excavator is never enough. I believe the main reliance is on the piers now. Alex We do use sand, which is a 50mm binding sand between the soil and the slab. Sand on it's own wouldnt be stable enough to support the formwork, think about building a sandcastle on the beach, it is very hard to stop them from collapsing. The purpose of the piers is to bear the slab to rock, we have around 60 x 450 diameter piers. Cheers Simeon Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 35Sep 22, 2023 10:26 pm alexp79 Why soil, not sand? You would generally do not want to have reactive soil under the slab. Also, compaction with excavator is never enough. I believe the main reliance is on the piers now. Agree that compaction from tramming isn't usually enough, but if the lifts are thin enough and moisture content is good then shouldn't be a problem. Perth Re: Building a flame zone house in West Pymble on a steep si 36Sep 23, 2023 6:59 pm ML24WA alexp79 Why soil, not sand? You would generally do not want to have reactive soil under the slab. Also, compaction with excavator is never enough. I believe the main reliance is on the piers now. Hey Alex, you should look up AS1726. Soil comprises all sorts of different particle sizes and compositions. Sand is actually a particle size range, as is silt and clay. Agree that compaction from tramming isn't usually enough, but if the lifts are thin enough and moisture content is good then shouldn't be a problem. Silt and clay are not self-draining, so they are not really facilitating the removal of water from the soil under the slab, and, therefore, if site is not maintained properly, the issues might still appear: even with piering and slab-in-ground systems the heaves are still possible on reactive soils (although slab-in-ground will be certainly less prone in comparison to slab-on-ground). Using a deep enough layer of well compacted sand or gravel or combination of (usually 20-30 cm) under the slab and footings, instead of reactive soils, coupled with proper perimeter drainage, provides very reliable protection from water under the slab and in most cases can eliminate the necessity/requirements for piering even on highly reactive and unstable soils. If slab-in-ground system is used, then footings can be also placed on top of 10 cm layer of well compacted sand and gravel and poured, however, with the above mentioned approach you don't really need slab-in-ground, slab-on-ground systems such as simple waffle pods or more advanced systems slab-on-ground systems used in northern countries such as Dorocell Foundation System or Dow Plate Foundation (it allows to build reasonably heavy houses on soils with bearing capacity of 30kPa or less!) can perform as well as typical slab-in-ground system on piers or even better, and at the same time, will significantly reduce the risks associated with maintaining the slab perimeter and protecting it from the water. If there is no soil freezing, there will be no specific need to maintain concrete path/protection around the house (other than aesthetical), no need to grade away soil and deploy clay locks and temporary downpipes during the building - the system is much more forgiving for typical building and maintenance mistakes and water flooding associated issues. You would certainly spend extra on sand/gravel, proper compaction, and in some cases on extra concrete and reinforcement, but then you save on costs of piering, formwork, additional ground works and pours (such as excavation of footings and backfilling required for slab-in-ground systems as well as separate pours for footings and slabs). Simeon, what is your estimate spend on slab, piering and footings including ground works and how big is the slab? Re: Building a flame zone house in West Pymble on a steep si 37Sep 23, 2023 7:48 pm Yeah cool. I understand geotechnical engineering. All I was pointing out is the correct terminology, also, if the soil underneath doesn't come into contact with moisture, then the clay is fine to use for foundations. Depends what the engineer specifies and how deep pockets are I guess? Perth Re: Building a flame zone house in West Pymble on a steep si 38Oct 09, 2023 6:53 am alexp79 ML24WA alexp79 Why soil, not sand? You would generally do not want to have reactive soil under the slab. Also, compaction with excavator is never enough. I believe the main reliance is on the piers now. Hey Alex, you should look up AS1726. Soil comprises all sorts of different particle sizes and compositions. Sand is actually a particle size range, as is silt and clay. Agree that compaction from tramming isn't usually enough, but if the lifts are thin enough and moisture content is good then shouldn't be a problem. Silt and clay are not self-draining, so they are not really facilitating the removal of water from the soil under the slab, and, therefore, if site is not maintained properly, the issues might still appear: even with piering and slab-in-ground systems the heaves are still possible on reactive soils (although slab-in-ground will be certainly less prone in comparison to slab-on-ground). Using a deep enough layer of well compacted sand or gravel or combination of (usually 20-30 cm) under the slab and footings, instead of reactive soils, coupled with proper perimeter drainage, provides very reliable protection from water under the slab and in most cases can eliminate the necessity/requirements for piering even on highly reactive and unstable soils. If slab-in-ground system is used, then footings can be also placed on top of 10 cm layer of well compacted sand and gravel and poured, however, with the above mentioned approach you don't really need slab-in-ground, slab-on-ground systems such as simple waffle pods or more advanced systems slab-on-ground systems used in northern countries such as Dorocell Foundation System or Dow Plate Foundation (it allows to build reasonably heavy houses on soils with bearing capacity of 30kPa or less!) can perform as well as typical slab-in-ground system on piers or even better, and at the same time, will significantly reduce the risks associated with maintaining the slab perimeter and protecting it from the water. If there is no soil freezing, there will be no specific need to maintain concrete path/protection around the house (other than aesthetical), no need to grade away soil and deploy clay locks and temporary downpipes during the building - the system is much more forgiving for typical building and maintenance mistakes and water flooding associated issues. You would certainly spend extra on sand/gravel, proper compaction, and in some cases on extra concrete and reinforcement, but then you save on costs of piering, formwork, additional ground works and pours (such as excavation of footings and backfilling required for slab-in-ground systems as well as separate pours for footings and slabs). Simeon, what is your estimate spend on slab, piering and footings including ground works and how big is the slab? Alex We budget around $280/sqm plus piers at $250 each but wont have the final figure until all drop edge beams and stairs are calculated at the end, and we know how much soil had to be removed as well. Cheers Simeon Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: Building a flame zone house in West Pymble on a steep si 39Oct 09, 2023 7:04 am Happy Monday everyone A quick post update. This is slab pour week. Since my last post we have installed all of the in-ground drainage and formed around 80% of the slab. Due to the complex nature of the slab in terms of the multiple sets of stairs, the large size and quantity of drop edge beams and the decision to suspend part of the alfresco to accomodate the pool equipment underneath, we have decided that it will be prudent to do the slab in 2 pours over 3 days. So day one Wednesday we will pour the lower slab. Thursday the boys will finish forming the pool coping, install bondek and internal stairs and then Friday we will pour the upper slab, pool coping and stairs. This will mean we need to waterproof the joint in the 2 slabs. We use a product called waterstop which expands and gives a tight seal when the concrete hits it. In terms of program, we will lose 2 days. Slab pour had been programed for the 11th but will now finish on the 13th. But overall I think we will get a better outcome by doing it this way, rather than rushing a big pour in a single day. The overall goal due to site access is to have all external concrete done now with the exception of the driveway which can be done at the end. So still on track for a May finish. Here are some photos from site taken yesterday. Cheers Simeon Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Yes it had a house on it. But Melbourne water only wanted something the original size of the existing house. We managed to fit a 45sq house on. 10 34361 First time building 2 storey home, is under construction (in Framing stage) in NSW. I have 3 toilets and need bidet spray in… 0 17413 Building Standards; Getting It Right! Hi everyone Planning a large house extension in New South Wales northern rivers with a BAL 29 Fire zoning. Has anyone had experience with this type of zoning and how much… 0 6548 |