Concrete base for concrete sectional garage - Concrete base

[Ramsay]

This is my first ever post bit of a novice.
I have bought a concrete sectional garage about 18 ft x 8ft
Its going to be erected in my back garden on part of the grass this will take up about half of the grass.
Iam going to lift about half of the grass then put down a sub-base then use a vibrating plate to flaten it.
Then hammer steel pegs into the ground with steel sheets for the frame work to hold the concrete in place the frame work will be 4 " high from the ground
What kind of dpm should i use and how much will it cost ?
I got a few quotes for the concrete from about £ 260 - £ 320 this is ready mix deliverd is this normal price
And whats the best method of getting a perfect flat surface when the concrete is poured in ?
Thanks

[lutonlagerlout]

1200 gauge visqueen polythene
concrete i would hazard a guess at 2 m3 which would be roughly £250
you need a piece of wood longer than the width of the shutter
as you barrow the concrete to its final resting place you spread witha shovel then tamp with this piece of wood till the tamp touchs the shutter both sides,then repeat in a reciprocating motion back and forth,when you are happy with say a 450 section move down to the next one ad infinitum
LLL

[seanandruby]

Depends on what finish you want IE, heavy tamp, light tamp, brush, or smooth trowel, power float etc;

[Ramsay]

thanks for the reply guys
the dpm does this come up 4 " aswell before the concrete is poured or does this just cover the bottom of the base ?
Garage is getting used as workshop / garage would be good to get a smooth even base as possible
And what type of sub-base should i use and how much should i buy.

[matt h]

dpc should come up, and if poss tuck back into wall . smoother finish would be by powerfloat, but as you are keeping costs down use a derby or plasterer,s float to finish, subbase see mainsite

[yourgardenworks.co.uk]

Ive just done the exact same thing in my own back garden. Iv'e used a 16 x 10 tarpaulin purchased from ebay for the grand some of £5 and i paid £165 for the concrete which was poured straight into the frame/shuttering, piece of piss as they say, took all of an hour too tamp then another hour to float out, easily good enough for a garage floor.

[Ramsay]

£165 thats a bargain the cheapest in glasgow i can get is £ 220
How much sub-base did you use ?

[yourgardenworks.co.uk]

i used about 4 tonne mate, there is a calculator on the main site which will tell you what amount you need.

[Ramsay]

forgot to ask i have herd i should put oil on the seel shutter so that i can be removed easy when the concrete sets.
Is this true ? would this affect the concrete in anyway ?

[Tony McC]

Mould release oil (aka Soap Oil) is NOT the same as, say, engine oil or cooking oil.

[Ramsay]

Another question for the experts
I have just layed all my typer 1 down but i have not yet hired the vibrating plate yet.
Can i leave it like this for a while or iam i best using the vibrating plate as soon as.
I have coverd the area with plastic sheets

[matt h]

best to compact in layers, but if you leave it a bit and then compact later cant see much harm:)

[Ramsay]

I have now used vibrating plate does this look ok for me to put shutter up now bit of a novice never done this before.

[lutonlagerlout]

looks fine m8,well done
LLL

[Ramsay]

Shutter up
When i get the concrete in should i remove the corner supports so i can tap the concrete level ?