Concrete finish / fall on external hard standing? (power trowels vs hand)

[julianf]

Ive progressed with this job to the point of setting the shuttering height.

In reality, id like a completely level surface, and for it never to rain... But the fact that rain exists makes me think that ill have to have a fall : (

The kerb at the edge of the plot is fixed / level, so its a case of adjusting the shuttering to give the fall.

Given that i would rather things are level, how much do you think i can get away with?

(hardcore has not yet been compacted, and retaining wall needs extending)

Also...

Id like the surface flat. Tamped finishes and hard castors never work well (eg engine cranes).

I dont have a power float, and, although i could hire one, id probably rather not do so. Its not a big area anyhow, so im thinking a troweled finish?

Is the only issue with troweling too early that the curing time is increased, or is there any structural penalty? And, with a hand trowel, is it really likely that ill seal the surface anyhow (i dont need to, but i read thats the issue with using a power float too early?)

 

[cumbriasteve]

I hand finished my garage floor with a steel float as it was laid, working inside the garage from back to front, so could not go over it once I had backed away.

It raised the water and initially looked awful with raised swirls but a week later I tied a house brick to an old brush and polished the surface keeping it wet at all times.. ended up with a lovely smooth finish with little effort.

I should point out I used the above method because basically I did not have a clue what I was doing, the expert down the road used the professional method, it's not as good as mine though so I was fairly pleased.

 

[garethp]

I used one of those big plate thingies on the slab next to my garage, floating 6m x 3.5m was a doddle

Google big blue float and you'll get the idea

You don't need much fall, can't remember what I used but wasn't much and the water runs off, what's the minimum drains shoul be laid at? Isn't it something like 1in110?

 

[stormin]

You can go as low as 1:150 falls if you are confident in getting the surface even, ie using a full length screed rail or float across the edge boards. Any unevenness at this will likely hold small puddles of water though. If you are first timer and not as confident I would stick to 1:100 as minimum fall.