[Eblana]

Hi all,

In the process of ripping out my deck at home to replace it with paving slabs and now have lots of lovely timber planks to use for raised beds on the plot (I swear this had nothing to do with the decision to take the deck out)  

Just wondering what is the best timber size & type to use for the corner spikes to drive into the ground and attach the boards to?

The deck boards were treated with oil about 4 years ago and are in perfect condition - do I need to treat them with anything now and also do I need to treat the corner 'spikes'?

[davejg]

My beds are 2.4m x 1.2m, I didn't use corner posts just put 3 decking screws through the ends into the shorter boards. these were plenty strong enough when they ore on the ground.

[Trillium]

Depends on how high the boards and bed will be and how long.  I used 2x6"s and simply screwed in the ends with 3" screws.

If you're using 1" thick boards, you'll want to use at least a 2x4" corner post, and if the bed is over 6 ft long, then add centre 2x4's to keep the bed from sagging outward over time. Someone I know had this happen and he had to pull the top together with 'cross beams' to strengthen the sags.

[grendel]

why dont you just use a short length of decking board as the corner posts, it will double the thickness for you to screw into. plus you already have it. - or how about a piece of the decking under frame?
Grendel

[Eblana]

thanks everyone for the replies.  I have some 2 x 6 so I will try that.  When we got the boards off the top of the deck the timbers underneath were completely rotted through so much to my disappointment they had to go for scrap (we were lucky the whole thing didn't collapse under us judging by the state of the under timbers.

[grendel]

when I built my decking I found some old 6x6 timbers that had been coated with old engine oil, from all reports my wifes grandad laid them down in case they were useful over 30 years ago, the wood was still in perfect condition, somehow I dont think they are going to rot too quickly.
Grendel

[Sideshoot]

2" sqaure timber should be ok, with 6 " or so to sink into the ground.