Concrete Round Two (Floor Slab!)

[VDubDan]

Right, after the not so great foundation pumping debacle it's concrete time again! This time the floor slab - oversite is prepped, DPM will be down tonight, building control tomorrow then concrete is coming on the weekend!

I'm going for insulation above slab as I'm rushing to get the concrete down before a business trip.

So my plan is to get the DPM down, pop some bricks in the corners and then go around and mark the edge with a marker pen for the concrete height. Concrete is going to be volumetric, and we're barrowing it in.

I was just going to start one end, get it to height, tamp it and work backwards until we get to the end?

And then just tamp it down - as far as I know there's no need to get an overly smooth finish here?

Any more tips for getting it nice and level etc?

 

[23vc]

I doubt your pen mark will last long. Work out the level and make a tamp 4x2 cut out so it sits on your brickwork as a guide but extends lower so it tamps the concrete at the right level.
If you’re having a screed then it’s not mega critical you just need approx the right depth, but pen marks will just get splattered and disappear

 

[VDubDan]

I doubt your pen mark will last long. Work out the level and make a tamp 4x2 cut out so it sits on your brickwork as a guide but extends lower so it tamps the concrete at the right level.
If you’re having a screed then it’s not mega critical you just need approx the right depth, but pen marks will just get splattered and disappear

Good shout, thank you!

 

[^woody^]

And then just tamp it down - as far as I know there's no need to get an overly smooth finish here?

Unless you want ridges and your insulation lifting all over the place, and dips for it to settle into later and the screed crack.

 

[VDubDan]

Unless you want ridges and your insulation lifting all over the place, and dips for it to settle into later and the screed crack.

Hmm, when I read the insulation docs they implied it go on a rough cast floor if you popped a bit of sand down first. Are you saying I should be trowel finishing?

 

[^woody^]

No. The surface finish needs to be flat and level, but not necessarily troweled

 

[VDubDan]

No. The surface finish needs to be flat and level, but not necessarily troweled

Okay - so careful tamping then!

 

[^woody^]

Just be careful with the leveling board as it's very easy to end up with a hump in the middle. Drag and shuffle it sideways rather than tamp it up and down.