Browse Forums Paving & Concreting 1 Dec 15, 2014 3:51 pm 1. The best results for slabs is when they are placed on a flat base so a base of crusher dust is going to be better than natural ground. 2 I would be going for a fall of 1:100 which means 80mm. 3. A steel float should be OK for a finish but how are you going to get a 8 x 8 slab flat? I would be looking to do it in no less than 2 pours of 4 x 8 which is easier to screed flat. 4. SL62 would be a good mesh (6mm bars at 200 centres) Concrete should be 25Mpa The more water you add the more shrinkage and cracking is likely. 5. Maximum spacing of joints should be around 25 x depth of slab. There should be less reinforcement at joints and the joints need to be cut the day after pouring. If I use formed joints to minimise the chance of cracking I always cut the joints a little deeper with an angle grinder the next day. There is some more information here: http://www.anewhouse.com.au/category/co ... /concrete/ The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Looking for advice for outdoor area slab. 2Dec 15, 2014 10:41 pm 20 /20 isn't the slump. This refers to the stone size and strength The standard slump is 80. You can't just add water or it will ruin the cement to water ratio which is a factor in concrete strength. You can add some water on site, but the more you do, the more shrinkage cracks will occur Up the slump to 100 and it will be easier to work. the put more cement in to compensate so it will be slightly more expensive Also, if you are going to tile it don't steel trowel finish it. if you glaze the top too much the tile glue can't bite into it as much. maybe a bit fussy but no point. Go hire a bull float. It will make you look like a pro. If you are in QLD I might even lend you one along with some screeds 8m x 8m is a big slab for a beginner, would be best to do in 1 pour and go a bit thicker than 100mm, but you are only 1 man unless you have some very very handy mates. 64m2 is pushing the limits on 1 truck load especially if you thicken the edges or the general area 7mm mesh is fine, think about deformed bar around the edges if it's going to be driven on If filling one corner thicken the edges down to natural ground Try and tie it into the pergola post footings You are a beginner, you will have plenty to worry about without control joints while it's wet. Yes, try and work control joins to grout lines if you aren't going to beef it up or you will pop or crack tiles. Grout lines over control joins should be filled with silicone not grout Andrew Re: Looking for advice for outdoor area slab. 3Dec 15, 2014 10:43 pm burtybear Thanks for the reply. Might consider 2 pours and box it in half like you suggest. If I do that do I need any expansion joint down the middle when I remove the boxing for the second pour or is it just a case of screeding the concrete to the height of the first one down the middle? If doing 2 pours dowel into the first slab CDC Housing Code 3 When to apply Floor Area external face of wall vs Gross Floor Area internal face of wall. Reading thru CDC Housing Code 3, lets take a lot 915sqm.… 0 16396 Thanks for letting us know. The programmer will have a look at this later today. 2 6636 About a year ago, I embarked on a DIY project to construct an outdoor Pergola, which measures approximately 5.2 meters by 4.0… 0 29553 |