Browse Forums Paving & Concreting 1 Sep 10, 2010 10:01 pm What is the difference between a HD and H class slab? We were given a free upgrade to H class slab and now PD are charging a difference for the HD. Everyone who is building around us is getting a H class slab. Do we have a choice with regards to this? Tarneit : The Reserve Re: Difference between a HD and H class slab 2Sep 11, 2010 10:07 am Primary difference is that they increase the slab by 15mm from 85mm to 100mm and chuck a higher grade of reinforcing in there. All up for a 26sq house your looking at $5k to $8k. Check to see if everyone else you quote as having H class have/havn't got piers because that wouldn't necessarily need a HD. Re: Difference between a HD and H class slab 4Sep 14, 2010 8:30 am It all depends on the type of soil and depth of any fill (clay). So for >0.5mtrs of fill you could have a H class slab with piers or HD class slab. Would be better to post your soil report regarding: Soil type Fill depth ... and we can go from there. I'm not an engineer but I have looked into slabs a fair bit. Re: Difference between a HD and H class slab 5Sep 20, 2010 12:22 pm Here is an image with all the relevant information http://yfrog.com/jwimage001ejj Tarneit : The Reserve The Soil classification has little to do with piers. The purpose of the classing of the soil is to identify the clay content and the "average expected range of movement… 2 9856 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 13100 I don’t think so as the floor area over 300 square meters then it is class 3…. 12 17936 |