You would need piers through the fill and they have to be distributed evenly, yes.
You would need piers for H1 too and sometimes even for M.
Send us your engineering report or drawing here when you get it.
Browse Forums Building A New House Re: Site costs 36Apr 30, 2020 12:09 am Hi again. Just bumping the thread..I have been searching all over about this but found limited info. If anyone know of similar scenario please share. Thanks.. I read on the general building recommendation to ensure site drainage, soil surface should be sloped away at 1:20 for a minimum of 1.2m width apron. How do I ensure this to happen? Is this something that is supposed to be written on the plan or contract? I am planning to get the concrete apron later around build completion, due to funds limitation.. I ask the builder last time about if I need piering at the back for future pool I was told no. Before I sign the contract, I want to know given that it's mentioned here that having piers distributed evenly is the way to go to avoid differential settlement..I'm confused why then the engineering report piers are only on one side.I have asked this question to the builder last week but haven't gotten proper response. I will ask again tom. Can this design work? Any suggestion? Has anyone had a piering done only on one side? if my lot has level 1 compacted fill, does it automatically need piering or not? In this instance, the bored piers are needed on one side being close to the retaining wall. So in general they don't recommend piering only one side? is this absolute? Re: Site costs 37Apr 30, 2020 12:42 am They claim that piers won't be needed if soil is compacted to at least 97, so you would need to see a report from soil compaction testing lab to confirm that. Generally, it is hard to move water away from waffle pods at highly reactive sites, so you must do what you can. I would start with a perimeter aggregate drainage and will make sure that when you cut for the site, there is a minimum slope at the bottom of excavation, so even if water gets under your slab and passes through sand, it is poured away with the gravity right into the drainage, otherwise, you will be just having a swamp under your slab after every rain, this will be disaster and no compaction will help you to go around. The easiest option will be to pier along the full contour, but I would still prefer to have drainage in place and slope under your sand. Concrete apron would help, but you would need to make sure that under the apron you have a clay and not sand or gravel as well as perimeter drainage, as otherwise the water routed away by the apron will still have a good chance to get under the apron and under your slab. Just my 2 cents. Re: Site costs 38Apr 30, 2020 1:53 am alexp79 They claim that piers won't be needed if soil is compacted to at least 97, so you would need to see a report from soil compaction testing lab to confirm that. Generally, it is hard to move water away from waffle pods at highly reactive sites, so you must do what you can. I would start with a perimeter aggregate drainage and will make sure that when you cut for the site, there is a minimum slope at the bottom of excavation, so even if water gets under your slab and passes through sand, it is poured away with the gravity right into the drainage, otherwise, you will be just having a swamp under your slab after every rain, this will be disaster and no compaction will help you to go around. The easiest option will be to pier along the full contour, but I would still prefer to have drainage in place and slope under your sand. Concrete apron would help, but you would need to make sure that under the apron you have a clay and not sand or gravel as well as perimeter drainage, as otherwise the water routed away by the apron will still have a good chance to get under the apron and under your slab. Just my 2 cents. Thanks for the reply Alex. Here is the compaction report. It looks like it's above 97% if I am reading it right? *edited I am not sure where to look for drainage plan but this is what I found in terms of roof water drainage, downpipes and field gullies I will ask more about the drainage.. Do you know the estimate cost for an engineer to supervise this stage? It says they don't do full supervision unless asked in writing, otherwise they will come for inspection only as per requirement. When you say pier along the full contour, you mean all of the sides? Re: Site costs 39Apr 30, 2020 2:25 am No, they say that they will be replacing up to 250 mm of soil under the slab with new fill and compacting it in layers in certain areas. This will be a pre-requisite for your slab preparation: We recommend that the site be cut and filled to form a level pad after being scraped free of significant vegetation. Any new fill should be clean (i.e. free from material which is subject to decay) and mechanically compacted in 150mm layers. This fill is not to exceed 250mm depth beneath the floor slab. Not sure about engineer to supervise the stage, I guess it will be better to discuss with the current engineer to make sure he specifies drainage and soil slope post excavation (confirm if "slope to front" label on the drawing is actually specifying it?). Also, he should specify that new fill under the slab to be porous and act as a drainage (e.g. sand, roadbase, sandstone, gravel, etc.). If it is a sand, then generally it is a good idea to install geo-textile to prevent compacted sand from mixing with clay. The drainage around the slab is not really related to your roof drainage and downpipes. Piers along all the sides, yes. I am not sure whether Perth has its own way of doing things in regards to this. Most of Perth has class A (sandy soil), except for some areas near rivers or hills. 2 13082 Is anyone building with Mojo and have a recent site cost tender 0 15951 Henley should give you some indication of site costs. Too many variable to give you any reasonable accuracy 1 1877 |