Easiest way to dig holes for posts

longwalks1

I’ve an area of about 15m2 of decking to build, raised (by about 30cm) over an old bald, uneven lawn (no grass left, as it was used to store 12 tonnes of type 1 for months).

what’s the easiest way to dig the holes for the decking support posts please?  Is there an easy way? And how deep should I go down? 

Any tips would be greatly appreciated

stuart45

Clarke CHT770 Post Hole Digger - Machine Mart - Machine Mart
If you feel lazy. https://www.hirestation.co.uk/tool-hire/Landscaping/Post-Hole-Borer-Hire/140050/
normally 2ft - 2ft 6in deep. I know some people have only gone 18 inch.

john.h

You don’t need to dig them 2ft deep, it’s not a fence. 

FreeBear

If you are using wooden posts to support the deck, I'd suggest using some cast-in post shoes like this - https://www.toolstation.com/cast-in-post-shoe/p50644

Wooden posts set in concrete will rot away in 10 years or so. And when they need replacing, it is a major pain to dig out 2ft of postcrete.

TELLIT01

I used something like this https://www.screwfix.com/p/spear-jackson-post-hole-auger/3911k  borrowed from a neighbour.

donemedosh

post spade or called drainage shovel about £25 from screwfix is what I use dig down about 12 to 18inches with either a half brick or gravel at the base fit in the post in add postfix job done.

Bradden

I'd recommend using these if you want something easy. 

https://www.supremeconcrete.co.uk/products/landscaping-products/urban-and-rural-landscaping-products/dek-blok-dekpost

casper_gutman

As others have said, in practice timber buried in the ground will inevitably rot (unless it's one of a few rare species of tropical hardwood).

I used solid recycled plastic posts for something similar, with pressure treated timber joists on top.

The holes for my deck had to be dug through hard ground with many roots, half bricks etc. I used a digging bar like this (but I can't claim it was easy!) - https://www.toolstation.com/roughneck-digging-bar/p48155

stuart45

john.h said:

You don’t need to dig them 2ft deep, it’s not a fence. 

Depends on the ground conditions and height of the decking. No one can be sure before you start digging.

Bigphil1474

I used a trowel to dig holes for the metal post holders things. About 18 inch through old coal/rubble seams/and the occasional bit of soil. I'm tight though. 

longwalks1

Thanks all - have ordered a set of the post hole digging chops (2 shovel heads fixed together).  Will use those then sell them on again once finished.  

If I go with wooden (treated) posts, would it be wroth painting them with something like bitumen paint to maybe preserve it a little longer?   

Decking will be about 10 inches from the ground, maximum height.  what size wood would you recommend for the posts too?