Thread: Low level deck - hardwood or TP frame?

Hi all,

I must have read about a thousand threads now and an equal number of web pages about this and I'm still unsure as to what to do! Help!

Here's the info:

- I'm building a low level uncovered deck (more like a boardwalk), 1.2m x 4.8m with either Jarrah or Merbau decking (140x19).

- The deck will meet an existing paved patio on two sides with the current ground level about 150 below the level of the patio.

- I plan to dig down as far as i need to get about 100 clearance between the bottom of the bearers and the final ground level. Drainage isn't an issue.

- I wont be using posts, just L shaped stirrups embedded in concrete.

I'm pretty happy with all of that. But have two questions about the framing (bearers and joists).

1. I want this thing to last a good 15-20 years. Initially I had planned to use hardwood but have read countless articles explaining that hardwood rots a lot more easily than TP. Is this true? What would I need to do to it in terms of treatment to make it last 15-20 years (without any post installation maintenance). I assume that TP would not require any further treatment, would last a long time but suffers from warping and being less structurally strong than hardwood.

2. I was planning on using joist hangers on the bearers (rather than joists on top of bearers) to save effort in digging down (joists on top would require me to dig an extra 140 or so down). Any thoughts on this and does this 'boxing' arrangement affect longevity of the framing?


Thanks all - looking forward to some good advice as usual!

Cheers
Dave