Concrete base for summer house - Quantities required

[ArdentAdmirer]

Before I start can I assure you that I have read other posts and other advice on this website. However, please bear with me! I am going to erect a Cannock 32 Log Cabin/Summer House bought from B&Q (Supplied by Shire buildings). I wish to construct a concrete base measuring 2820mm x 2200mm x 120mm deep (0.75 cubic metres). For various reasons I wish to use B&Q materials. I have used the calculator for materials required but instead of separate sand and gravel I would like to use B&Q's All in Ballast supplied in bags (I know I could buy in tonne bags but for various reasons would rather use B&Q "large" bags). I know the ideal mix should be 1:4 but because the bags of all in ballast do not have weights on them I do not know how many to order. Also, does the 1:4 mix mean by volume or by weight? Can any one help me to decide how many bags to order. Also, would I need to incorporate a wire mesh reinforcing into the base? Grateful for any help.

[lutonlagerlout]

dude before you order these bags why not make it 150 deep and have a metre of concrete delivered
the volumetric guys will wait,the concrete will be better and it will be done in an hour
I have heard of people bucketing concrete upstairs
I know that doesnt answer your questions but using small bags is an untenable way of doing it
LLL

[ArdentAdmirer]

Thanks LLL, I'll bear that in mind although going down another 30mm will be hard work considering the surface I will have to cut through. Ready mix will be a minimum of 1 cubic metre and I baulk at having to pay an extra £50 just for the convenience.

[lutonlagerlout]

1 cu metre costs approx £140 +vat
to buy 30 small bags cost roughly £60 +10 cement =£100
then you have to get a mixer and mix it
I understand if money is tight but it will take a diyer all day rather than an hour
LLL

[dig dug dan]

i concur with LLL. mixing by hand, especially bags, is no good, as the first batch you do starts curing before you have a chance to screed the whole thing

[DNgroundworks]

I to concur, id sooner find the extra £20.00 or so and get the barrow mix lads in, let them mix, pour and if your very nice get them to help you level it out.

[GB_Groundworks]

feck yeah, even with out big 3/4 cube diesel mixer i buy in anything over .5m cube collecting it from the bathcing plant, just cant mix it as well for the price