RichS Posted September 18, 2017 Share Posted September 18, 2017 I'm looking for quotes, other than the silly answers I got from Network Rail, for hardcore. Hilliard has specified 30-50 dia. so I'm assuming that I just want clean with no fines, would anyone agree with this assumption. Link to comment Share on other sites More sharing options...
jack Posted September 18, 2017 Share Posted September 18, 2017 The network rail stuff is, as far as I know, what some including me have used as a replacement (with Hilliard's blessing) for the specified 28-50 (from memory) angular no fines material. It's been a while, but I seem to recall that this is an unusual spec in the UK, which is why recycled rail ballast became of interest. If you can find a source of hard, angular, no fines material with a slightly different size range, I'd just give Hilliard a call and ask whether he's happy with it as a replacement. Not sure whether a revised formal spec will be required - worth checking with your building inspector. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted September 18, 2017 Share Posted September 18, 2017 I'm pretty sure the spec for ours was clean, washed, no fines, 18 - 35, which is not that easy to get here. I seem to remember we paid a fair bit for ours, as we weren't aware of the railway ballast option. Link to comment Share on other sites More sharing options...
jack Posted September 18, 2017 Share Posted September 18, 2017 1 minute ago, JSHarris said: clean, washed, no fines, 18 - 35 Just checked our spec and it's actually 30-50mm. Not sure where I got the 28mm lower number from! Link to comment Share on other sites More sharing options...
RichS Posted September 18, 2017 Author Share Posted September 18, 2017 Half the area of what will be the new house footprint is where I have just knocked down my original garage. This area already has a 300mm layer of 40mm down MOT1. Obviously with the price of hardcore I am reluctant to just dig this out and skip it. What are the views on using this as a base layer over the complete area and then topping it up with 20-40 clean. Or alternatively trying to mix this material in with 20-40 clean so you end up with a hybrid mix. Link to comment Share on other sites More sharing options...
RichS Posted September 18, 2017 Author Share Posted September 18, 2017 (edited) And another question I've just spoken with two local quarries. The first one is charging just over £15 + VAT per ton for 40mm washed limestone, the other is charging just under £10 + VAT per ton for 40mm washed hard chalk. Obviously the latter is the favourite but is hard chalk acceptable?? Edited September 18, 2017 by RichS Spelling Link to comment Share on other sites More sharing options...
Gone West Posted September 18, 2017 Share Posted September 18, 2017 42 minutes ago, RichS said: Half the area of what will be the new house footprint is where I have just knocked down my original garage. This area already has a 300mm layer of 40mm down MOT1. Obviously with the price of hardcore I am reluctant to just dig this out and skip it. What are the views on using this as a base layer over the complete area and then topping it up with 20-40 clean. Or alternatively trying to mix this material in with 20-40 clean so you end up with a hybrid mix. Under my PH slab I have 250mm type 1 compacted and on top of that 50mm granite fines then the insulation. What you need must surely depend on the ground conditions. Link to comment Share on other sites More sharing options...
jack Posted September 18, 2017 Share Posted September 18, 2017 46 minutes ago, RichS said: Half the area of what will be the new house footprint is where I have just knocked down my original garage. This area already has a 300mm layer of 40mm down MOT1. Obviously with the price of hardcore I am reluctant to just dig this out and skip it. What are the views on using this as a base layer over the complete area and then topping it up with 20-40 clean. Or alternatively trying to mix this material in with 20-40 clean so you end up with a hybrid mix. I doubt mixing is going to be the way forward, as it will affect the way loads are transmitted. As I understand it, no fines means that the larger pieces will lock together under load. I wouldn't speculate about something as literally fundamental as this. Hilliard is a really helpful guy. He knows your house and your ground conditions. Give him a call and I'm sure he'll set you straight within a couple of minutes. Link to comment Share on other sites More sharing options...
RichS Posted September 18, 2017 Author Share Posted September 18, 2017 9 minutes ago, PeterStarck said: Under my PH slab I have 250mm type 1 compacted and on top of that 50mm granite fines then the insulation. What you need must surely depend on the ground conditions. Hi @PeterStarck, Thanks for that, I assume you mean 5mm granite fines?? Link to comment Share on other sites More sharing options...
Gone West Posted September 18, 2017 Share Posted September 18, 2017 @RichS I can't find the spec. at the moment but 5mm max. sounds about right. 1 Link to comment Share on other sites More sharing options...
RichS Posted September 19, 2017 Author Share Posted September 19, 2017 So the digger man started today. The existing MOT1 hardcore that I mentioned earlier, I am digging down 150mm deeper than required and then going to spread this MOT1 to form a sub-base for the 30-50 clean. The slab will still end up with the 300mm of clean as required but sat on a MOT1 sub base. Just to re-ask a question that no one took up on, has anyone used hard chalk for their hardcore?? Link to comment Share on other sites More sharing options...
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