laying a concrete floor

[thinfourth2]

Got all the kit and have the shuttering up just the question is is it better to lean towards a wet or dry mix if i am wanting a decent finish on the floor

It is only for a greenhouse floor so strength doesn't need to be huge but it will only be about 2inches thick in some places so it can't be too weak.

I laid a bit of it last night and found if it was too dry it was a complete bugger to float so i am tempted to lean towards a wet mix but could this give me problems later on.

[thinfourth2]

Well it is on very solid base just its not exactly level so its 6" at one end and 2" at the other

And no its not simple to dig it down further as i'm not hiring a JCB with a breaker to get through the rocks

[thinfourth2]

Cut and in position

[thinfourth2]

Oh for fksake

Okay i have now changed it to 7 foot thick of military grade concrete

Whats the best way to get a decent finsh

[thinfourth2]

Deva Link said:

thinfourth2 said:

And no its not simple to dig it down further as i'm not hiring a JCB with a breaker to get through the rocks

What about hiring a piling machine?

Its a greenhouse if the steading next to it hasn't moved in the past few hundred years with no foundations i don't think a few tomatoes are going to cause massive problems

It is actually all the top soil removed and throughly pouned with a big vibrating roller and then sub base added which is then pounded again with a roller so it should be fine.

The ground is comedy hard with even a JCB struggling to dig more then a few feet down

[thinfourth2]

Si 330 said:

The problem is at just 50mm it will crack. Your choice you can stop this from happening now or regret later.

its a fkING GREENHOUSE

it built on fking granite rock not your namby pamby english soft squishy stuff

I don't give a flying fk if it cracks

Its a fking greenhouse

I just want to get a better surface finish so when i do the garage with 8" of concrete and rebar i can get is nice and flat

[thinfourth2]

Si 330 said:

thinfourth2 said:

Si 330 said:

The problem is at just 50mm it will crack. Your choice you can stop this from happening now or regret later.

its a fkING GREENHOUSE

it built on fking granite rock not your namby pamby english soft squishy stuff

I don't give a flying fk if it cracks

Its a fking greenhouse

I just want to get a better surface finish so when i do the garage with 8" of concrete and rebar i can get is nice and flat

Garage slab will be more than adequate with 150mm thick slab light mesh such as A142 to control cracking. You go from one extreme to the other, calm down. People give friendly advice and you get all upset.

The garage will have a 2 post lift and some rather large lumps of machinery like a lath and milling machine which i want damn solid

[thinfourth2]

deeen said:

The reason people reccomend minimum 4" is because with less than that, the expansion and contraction of the concrete you lay could be enough to crack it. It's nothing to do with the base underneath.

Mesh will help

The answer to your question is wet

My suggestion which you didn't ask for would be to use a waterproof self-levelling screed inside the greenhouse for the best finish.

How do you make a self levelling screed?

I have a large pile of gravel and a small pile of sand and a fiesta full of cement bags

(fiesta is currently being used as small mobile garden shed/greenhouse which is great as you can drive your garden shed around the garden to where you need it.)

As to expansion and contraction i am making the base out of small bays with wood strips between them as expansion joints as recommended by my father who has been a builder for years and has always done it that way but is in spain so i can't easily call him

[thinfourth2]

andy43 said:

Ebay cheap flags is the answer - concrete is silly expensive, even if you mix it yourself.

Free cement and concrete mix at £20 a ton

Not too costly

So far a base 5m x 3m has cost me £80

[thinfourth2]

Concrete mix is gravel and sand mixed in the correctish ratio

You add cement and mix and bingo you have concrete

Sadly my mixer is a bit ill

Which leads to my next thread