Workshop help - cubic feet

[Rob_H]

I'm obviously being a bit of a spanner but I want to get this right - all work on my new workshop stopped when:

a. thebathroom needed replacing
b. teh septic tank gave up the ghost and we needed a new treatment plant
c. Mrs H wanted a new fireplace - Victorian log fire to replace newish woodburner

and she diverted my entire budget!!!

I now need to do a few things myself including the base. If the base is 45' x 20' x 6" how many cubic feet of ready mixed cement would I need? Any ideas on pricing off the top of anyone's head??

 

[tiler99]

16.67 cubic yds ( about 450 cubic ft) according to this http://www.concretenetwork.com/concrete ... ulator.htm

 

[ike]

450 cu ft = 12.75 cu m . Make it a tad thinner and you will get away with 2 x 6 cu m loads. Buying a full mixer load will work out cheapest as most companies will charge a part load surcharge. Not sure on actual prices as of late but a minimix batch runs maybe £80 per cu m. A full 6 cu m load maybe £65-£70 a cu m. I reckon around £1K give or take.

cheers,

Ike

 

[Rob_H]

Cheers for the very prompt response everyone. Have to start digging out the hole now....

 

[tiler99]

There is a price guide here
http://www.pavingexpert.com/concrete.htm
Bottom of the page

 

[Shultzy]

Rob, don't forget to allow for the hardcore, and put some reinforcing steel in the bottom of the concrete to make it stronger. More importantly 12 cu m is a lot of concrete, so make sure you have enough friends and neighbours to help shift it if the lorry can't pour directly into the base.

FWW 1 cu m is nearly 40 barrow loads.

I would also suggest that you lay it in 2 x 10' wide bays, as a tamping bar 20' long will sag in the middle if you don't hire a steel one.

 

[RogerS]

FWW 1 cu m is nearly 40 barrow loads.
.

And there's me with only 4 cu m to lay. Aren't I the lucky one, then? :?

 

[woodshavings]

...... the base is 45' x 20' x 6" .....

Thats not a workshop - its a house!!

:mrgreen:

 

[devonwoody]

And a plastic/rubber membrane?

 

[nickson71]

insulation and sand too

 

[DomValente]

Maybe some pipes for electrics

Dom

 

[Rob_H]

You're all just not trying to put me off are you?

 

[Rob_H]

How hard is it to actually lay concrete and get it level? I have never tied before and if I get ready mixed delivered it wwill save a hell of a lot rather than getting a builder in - but bit worried I'll screw it up...

 

[devonwoody]

You need two people plus.

and dont stand in the stuff too long.

And take on board the logistics above.

 

[OLD]

The base will need shuttering say 5x1.5 min nailed to stakes driven into the ground long runs may need further bracing all leveled to the position of the top of the concrete this is not easy on long runs so hire a laser level to set boards before nailing off. In this box adjust ground level to accommodate compacted stone /crush&run etc then min of 25mm sand all compacted with plate vibrator to a level to give required depth concrete a poly sheet overlapped at joints is next dressed up the boards and cut of say 75mm above (this can be cut of flush when filled just before final tamp)
A tamping board min 2.0 thick with a good edge and wider than the base is required with long handles to allow both a sawing action and a compacting action is required. calculate concrete required lay and tamp. Further timber for a 'bridge' will be required if you want a smooth floated surface.
Its lots of work and you need men at the laying in case some one has a back problem. Use a garden rake to move concrete around.

 

[RogerS]

You make it sound so easy, Old :wink:

 

[Rob_H]

Does anybody have any ballpark figures if I was going to have a builder do this instead?

 

[Adam]

Can't help with builders figures but you can read down mine and see at the bottom what I did by way of laying a base.

https://www.ukworkshop.co.uk/forums/view ... hp?t=11686

Adam

 

[RogerS]

OK - here's a few questions having just laid a few sq m for the first time.

Belle cement mixer used. Ballast and cement ...6 to 1 ratio

When mixing, larger stones seem to separate out on top and not get mixed in with the rest and so don't bind together very well as it's laid. Any recommendations?

Mix consistency - very difficult to get the same between loads. Gloopy is good...bit like porrdige consistency - as it flows better but concerned after reading you shouldn't use too much water. A drier mix was more difficult to lay and tamp down.

After a while, water can be seen floating on the surface. Assume this is normal but how soon do you trowel off to try and get a smooth surface?

Small air bubbles seen coming out of the concrete. Assume this is normal?

Comments very welcome

 

[devonwoody]

The surface water is normal, you cant do anything about the large aggregate at the surface now. Just hope that it stays secure.

By the way the last time I had ready mix concrete delivered it cost me £6 cu.yd. , and our bungalow cost £995. those were the days. But we had to lay our own paths and bungalow surround.