How to design deck and spacing of stumps?

[gspencer]

I am looking to build a 7m x 2.5m deck as part of the path on the side of my house. The deck will be over soil and the bearers on one side can be attached to the house brickwork, however I am struggling to understand the variables to determine the timber that I need to use of the bearers and joists and how far apart I can place the stumps. Digging the stump holes into clay is the bit that I am least looking forward to, so I don't want to do more than I need to, but I am not sure if its viable to span the 2.5m width or if I need to put in stumps in the middle. Is there any literature or online calculators that makes this a bit easier? 

[MitchellMc]

Welcome to the Bunnings Workshop community @gspencer. It's wonderful to have you join us, and many thanks for your question about building a deck.

You might like to start with these helpful guides: How to build a low-level deck, How to build a deck, How to understand deck span tables and How to understand deck components.

You can certainly span the 2500mm, but you'll need at least 140 or 190 x 45mm to do so.

Please let me know if you have any questions.

Mitchell