Allotment Gardening Advice Help Chat

Chatting => Design and Construction => Topic started by: noshed on February 06, 2008, 16:02

Title: concrete mix
Post by: noshed on February 06, 2008, 16:02

I have to build a concrete slab 10'x8'2", 3-4" thick. How do I calculate how many bags of cement, gravel whatever to buy. (It's for the base for our famed allotment trading hut, which is now becoming a reality).

Title: concrete mix
Post by: Sally A on February 06, 2008, 16:06

think I googled for the concretecalculator

try this one


http://www.practicaldiy.com/general_building/concrete_calculators/concrete_calculator_2_m.php#paving

Title: concrete mix
Post by: Ruth Cross on February 06, 2008, 16:12

As a quantity surveyor this is my dream question, sad I know;
 you'll need total of 0.66m3 concrete (for slab 3.5inches thick), the amount of bags of material you will need depends on the mix you want; coarse, fine etc.

I'm sure the builders merchant or the info on the bag will tell you how many you need to make up the quant with the mix you require :wink: Hope that helps

Title: concrete mix
Post by: Sally A on February 06, 2008, 16:14

Ruth, it sort of shows you've been waiting since the 5th Oct 2007 for that one to come up :lol:

Title: concrete mix
Post by: Ruth Cross on February 06, 2008, 16:15

OHHH YESSSSSSSSSS :lol:  :lol:  :lol:

Title: concrete mix
Post by: David. on February 06, 2008, 19:31

As a retired Quantity Surveyor, the above estimate is correct if the concrete is being spread on a dpm or sand/etc. fully blinded hardcore base, but more would be required if poured onto an open hardcore base.

I always used the guides in the front of commercial pricing handbooks , such as 'Spons' & 'Laxtons' from the office library, rather than info. from builders merchants.

Title: concrete mix
Post by: poultrygeist on February 06, 2008, 20:55

Quote from: "Sally A"

think I googled for the concretecalculator

try this one


http://www.practicaldiy.com/general_building/concrete_calculators/concrete_calculator_2_m.php#paving

I used this site for material calcs when I laid some strip foundations recently and it was pretty accurate. I've got 2 bags of ballast left over.
Best of luck with the slab.
Rob

Title: concrete mix
Post by: noshed on February 06, 2008, 22:53

Thanks chaps, much appreciated

Title: concrete mix
Post by: noshed on February 08, 2008, 15:58

I think my head has just exploded. The shed co reckon a base 305x247cm, say 10cm deep = 753350cm3 = .75m3?
My decimal points may have gone awry.

Title: concrete mix
Post by: noshed on February 08, 2008, 16:01

This seems to need 8  50kg bags of cement and a cubic meter of ballast - any idea how much this would cost (very roughly). Sorry about this I have to speak to some old Italians tomorrow.

Title: concrete mix
Post by: poultrygeist on February 08, 2008, 16:42

Using Wickes prices it's about £3/bag for a bulk order of 25kg bags.

Might get a better deal delivered from a builders merchant.

Jumbo bag of ballast which is, I think, about 700 or 800kgs about £35-£40 delivered.

Might be worth hiring a small mixer for the day/weekend.

Speeds the job up no end.

Best of luck.
Rob

Title: concrete mix
Post by: noshed on February 08, 2008, 23:07

Excellent, thanks a lot

Title: concrete mix
Post by: Tinbasher on February 09, 2008, 00:57

Quote from: "noshed"

I think my head has just exploded. The shed co reckon a base 305x247cm, say 10cm deep = 753350cm3 = .75m3?
My decimal points may have gone awry.

Ten foot is more or less 3 metres (3050mm more precisely) and 8 foot is more or less 2.5 metres, so that's 7.5 metres squared.  Four inches is 100mm (ie a tenth of a metre) so the answer is 7.5 times 1/10 = 0.75 cubic metres.

Title: concrete mix
Post by: noshed on February 09, 2008, 11:00

I am a mathematical genius after all. thanks

Title: concrete mix
Post by: noshed on February 09, 2008, 20:43

It has all gone well - £66! And a lovely flat thingy

Title: concrete mix
Post by: poultrygeist on February 09, 2008, 20:47

Well done !!

Now you're an expert you can come and re-lay my drive !

 :)  :wink:

Title: concrete mix
Post by: noshed on February 12, 2008, 18:40

The shed arrived this morning. May be pics by the weekend

Title: concrete mix
Post by: noshed on February 21, 2008, 14:21

The joint Italian-Turkish-East End building team have now put the shed up but not the doors apparently. Won't be able to see it until the weekend though.

Title: concrete mix
Post by: noshed on February 25, 2008, 22:18

Here(http://i241.photobucket.com/albums/ff100/noshed/100_2170.jpg) it is...

Much multi-lingual swearing went into this - and that was only the instructions

Title: concrete mix
Post by: poultrygeist on February 25, 2008, 22:56

That's a beautiful sight....the shed, not the team.

Our local kebab shop owner taught me some Turkish swear words but I've forgotten them all now.

Give them a hearty pat on the back. You must be very proud !  :D

From noshed to oneshed.

Rob