Browse Forums Paving & Concreting Re: Photos of 50mm fall to concrete apron 17Jul 17, 2015 2:23 pm You have to factor in that soil at edge of your paving can heave up on reactive soil. I have seen paving heaved and having a negative fall toward home. Therefore 50mm fall away in the first metre will give you a fighting chance against negative slope Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Photos of 50mm fall to concrete apron 18Jul 17, 2015 3:58 pm Stewie D Quote: 50mm fall over what distance? Or do you mean a 1 in 50 fall? No, according to the BCA - Surface Drainage. "Surface water drainage must be graded away from a building with a minimum gradient of 1 in 20 over the first metre." ( that is 50mm ) Go argue with them qebtel, I think it is a bit steep as well. Something like a 20mm fall over 1m would in 99% of cases be more than enough. Stewie 50 mm fall at 1 metre away from the slab edge that is sorry. Re: Photos of 50mm fall to concrete apron 19Jul 17, 2015 7:20 pm just retrieved from the 2015 NCC Vol 2 ( free registration - download the pdf ) my bold and underline where relevant. 3.1.2.3 Surface water drainage Surface water must be diverted away from Class 1 buildings as follows: (a) Slab-on-ground — finished ground level adjacent to buildings: the external finished surface surrounding the slab must be drained to move surface water away from the building and graded to give a slope of not less than (see Figure 3.1.2.2)— ](i) 25 mm over the first 1 m from the building in low rainfall intensity areas for surfaces that are reasonably impermeable (such as concrete or clay paving); or (ii) 50 mm over the first 1 m from the building in any other case. (b) Slab-on-ground — finished slab heights: the height of the slab-on-ground above external finished surfaces must be not less than (see Figure 3.1.2.2)— (i) 100 mm above the finished ground level in low rainfall intensity areas or sandy, well-drained areas; or (ii) 50 mm above impermeable (paved or concreted areas) that slope away from the building in accordance with (a); or (iii) 150 mm in any other case. If I interpreted correctly, a concrete or paver path need only slope 25mm over 1 metre, so 1 in 40. Re: Photos of 50mm fall to concrete apron 20Jul 17, 2015 7:27 pm Depends on the area. low rain intensity- that would suffice. I will be a H2 site so the 50mm fall a metre away from slab edge for me plus what BE said about slab heave applying to your apron as well that may push up apron edge so 50mm gives the apron a better chance of success. 50mm fall will work fine as a apron/path and it will look fine by eye as well. If you are going to the trouble and expense to do the apron, the extra 25mm fall to make it 50mm I say. It won't cost you extra. You are correct. Just read through all the ncc rules and 75mm is the minimum requirement for me. 4 11177 Thank you Splashers. Tomorrow I might check if I can get a few packs of 300x300 in the same tile finish. It may be good to use these could in the shower recesses. I'm not… 4 4682 I've got a challenge here. Background is the builder has cut too deep for the slab and the slab is now below the very substantial retaining wall. It's failed occupancy… 0 18392 |