pad for pier

[speach (Simon)]

I'm about to start digging a hole for the concrete pad for my pier. I was wondering how big it should be? I was thinking that a .5 cu/m of concrete should suffice so if that's how big it needs to be? Would a 1 m x .5 m x .5m or a .79m x.79m x .79m be better. Do you all think that a .5 cu/m pad is to big?

[glend (Glen)]

Plenty of folks will argue that 1 cu mt is required. Mine is 700mm x 700mm x 700mm. Wide at the bottom tappering in a bit at the top. Reo in the footing with pieces of angle iron dtiven into the bottom. My pier is concrete so it was poured in a tube form with reo running through to the bottom of the footing and 3 x s/s j bolts for the pier plate.
The mass really depends on what you intend to put on top, better to big than to small.
Of course, don't even think about having to remove it in the future.

[h0ughy (David)]

http://www.iceinspace.com.au/forum/a...e.php?a=200789 4.6cubic metres

[doppler (Rick)]

It depends on how hard your ground is, mine is hard packed sandy loam getting into sandstone at the bottom. My pier hole is 400 x 400 at the top, slightly wider at the bottom and 700 deep .