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  • Help me work out how much cement/sand I'll need….(please)
  • stumpy01
    Full Member

    A while back I posted about how best to go about filling the pond in the back garden in and I’ve made some progress.
    This weekend I want to get it finished and have lined up a couple of mates to help out.

    I was trying to work out how much sand/cement I’ll need to finish the job off and it seems like an awful lot.

    I’ve put down some hardcore, but need to put down some more as one bag wasn’t enough. I am planning on hiring a whacker plate to flatten that off and then use about an inch of sand/cement wet mix (web seems to suggest a 6:1 ratio) and then lay the slabs on top of that.
    The area is about 9.4m^2 and so an inch deep would give me a volume of 0.235m^3 (9.4*0.025) From what I have seen online this will require about 20 bags of the 25kg pre-mixed concrete. I was looking at the pre-mix stuff for ease of calculating, but will probably buy the sand/cement and mix it myself.
    If 20 bags is about right, then I supopse i’ll need 3 bags of cement to 18 bags of sharp sand for a 6:1 ratio.

    I don’t really want to end up with loads of left-over bags that I have to get rid of and equally I don’t want to keep having to go back to the builders merchants to buy more while doing the job.

    I keep imagining 20 bags of this stuff and it seems like an awful lot for just an inch thick layer. Does this sound about right? All help gratefully received!

    boblo
    Free Member

    Footflaps is your tame QS……just be prepared to hire a bulldozer as well 🙂

    wrightyson
    Free Member

    6 bag of op, (dont want it too weak as its thin at an inch)and a bulk bag will work out cheaper. You’ll have approx 250 kg left over. Works out at about 550 kg so if you go down the bags route it’s 550 divided by the bag weight.
    Im not sure it’s 25kg in a bag at my merchant.

    footflaps
    Full Member

    Footflaps is your tame QS……just be prepared to hire a bulldozer as well

    Don’t forget to hire a trained Cat to drive the plant on site…


    George the digger cat by brf, on Flickr

    grizedaleforest
    Full Member

    Your figures sound about right to me. I did a similar size area a few years ago before laying Indian sandstone flags, though I used a dry mix at about 1:10. I ended up using more than I’d calculated. If you haven’t already discovered it Paving Expert is a fantastic resource for home groundworks!

    BlindMelon
    Free Member

    General purpose sand/cement pre bagged will use 1.8kg/mm thick/sqm

    so 1.8 x 25.4 x 9.4 = 429.76 kg / 25 = 17.19 so 18 bags

    stumpy01
    Full Member

    Cheers all!

    wrightyson – Member
    6 bag of op, (dont want it too weak as its thin at an inch)and a bulk bag will work out cheaper.

    Yeah, I did wonder if this was the way to go; a bulk bag of sharp sand, but not sure how to go about getting rid of the left over…stick an ad on gumtree or freecycle I suppose for free sand?

    I take it by op, you mean cement? Original Portland? Sorry for the clueless questions!?
    I could go a bit thicker to try and use it all up? I guess from your weights, roughly an inch and a half would use it all up?

    grizedaleforest, yeah thanks, I discovered Paving Expert last night and had a quick look through it. Should probably revisit this evening.

    footflaps – I don’t have any feline trained plant operators although Presley is keen to learn:


    13-08-16 DSC_7755 by STW stumpy01, on Flickr

    although tends to lose interest quite quickly!


    13-08-31 DSC_7899 by STW stumpy01, on Flickr

    wrightyson
    Free Member

    Yup ordinary Portland cement. Prob pay 35 quid for a bulk bag and 4 for your cement. There isn’t a great deal in it price wise over the small bags as they’ll be £1.25 ish.
    However pre mix will cost you triple the amount…

    boblo
    Free Member

    You/your wife has a lovey pussy 🙂

    stumpy01
    Full Member

    wrightyson – Member
    Yup ordinary Portland cement. Prob pay 35 quid for a bulk bag and 4 for your cement.

    Bulk bag from Wickes is coming out at £38, but they charge stupid price for delivery. There’s a small place near me that will probably charge a bit more, but free delivery.
    20 bags of sand is, like you say, £1.25 each – so £25. But probably more from local place or have to pay for delivery.
    Cement looks to be about £5.50 a bag.

    It’s all starting to add up. I thought it would be a dead cheap job, but in total it’ll be way more than I thought (serves me right for not doing any research before I started, or budgeting).

    2 bags hardcore @ ~£40 ea.
    1 bag sand @ ~£40
    cement ~£25
    Slabs, 60 @ £2.08 ea. ~£125
    Whacker plate hire for the hardcore ~£40
    New builders’ shovel – £20
    New Spirit level (might as well buy one) ~£20?

    Gonna end up being about £350 all in….

    boblo – yep. He’s a pain, but he is a gorgeous erm, cat….

    wrightyson
    Free Member

    If a jobs worth doing….

    footflaps
    Full Member

    footflaps – I don’t have any feline trained plant operators although Presley is keen to learn:

    Just hire a digger and stick cat treats on all the controls – he’ll soon figure it out.

    BlindMelon
    Free Member

    Stumpy where are you based? I can possibly help with sand/cement in 25kg bags

    stumpy01
    Full Member

    BlindMelon – nr Peterborough…

    BlindMelon
    Free Member

    YGM

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