concrete planter shuttering

[mkmly]

Hi All

I'm attempting to build a concrete garden planter - 6" thick wall, 1/2m high running about 9m around a small square garden. The client would like it to have a 'timber grain finish' from the shuttering. Does anyone know how fine the concrete ballast should be to achieve this. Most ready mix bags have a 10mm ballast - I'm guessing any smaller would lack sufficient structure, but does it leave a sufficiently finished surface?

Having not really done this before, any tips on good shuttering and rebar requirements would be appreciated especially as the timber grain effect is a mostly one shot project.

Cheers

Mark

[thedoctor]

We think you're on a hiding to nothing here Mark. To get the grain showing the vibration needs to be absolutey perfect and to achieve that, the timber also needs to be pretty grainy. This usually means having a joint especially at 500mm high and getting the grain to show but the joint hidden is, we believe, impossible. This means several hours concrete finishing when the shutter is struck to get rid of the joint which will probably leave a non grain stripe. If anyone believes they can achieve what Mark wants we would be really pleased because we have never succesfully managed it!

[mkmly]

Thanks for that.

What other options are there - making the wall thicker, lower, hiring a good vibration machine?

If we forget about the timber grain, what sort of finish does shuttering usually give? I know iron railing installers can spend quite a while finishing the concrete bases to their fences.

Mark

[thedoctor]

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