All gear, some idea, and three simple questions!

Hi all,

Long time lurker on these forums (picking up some great ideas) but now time to put thoughts into action - and it's more questions on low-level deck!

Basically, I'm just wanting to deck over an existing concrete slab at the front of my house. Nothing fancy or spectacular - just a simple, straightforward approach that I think will look much nicer than what's there at present!

I've also got a very experience woodie down the street to help out, but before I go see him, I need to demonstrate at least some knowledge! Through this site, and web research, I've got some info, but just wondering if I could ratify that with some expert thoughts?

First, joists will be secured direct to slab. I'm not worried about water damage - slab gets good run-off, and if they're anchored down (dynabolt), I reckon they'll be good for at least 10-20 years (and that's way longer than a Gen Y like meself will be in the house for). As I'm trying to keep overall level as low as possible to existing height, would 70x35 treated pine (H4) be suitable here?

Second, I'm wanting to deck with 90x19 batu, secured with 42mm deckpoint screws. If my public school maths works out okay, joists (35mm) plus decking (19mm) give total height of 54mm - will 42mm screws be suitable?

Some background (if it helps with analysis/answers): overall slab is 6810mm x 1560mm. I was going to run joists along the short axis (1560) and deck lengthways.

Sorry for such a simple question, and thanks for your time and consideration!


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