Decking joist spacing?

darkwarrior

I'm trying to build a small deck as a DIY project. I was following a plan in a book but realized that it isn't incredibly specific in all the stages for things like joists and support beams. It has diagrams but no measurements.

The bulk of the frame is made from 76x48mm wood and support beams that are 75x75mm.

It's 2.4x2.4m, has a 2.4m central joist with two centre cross joists and a 75mmx75mm support block at each intersection. I'm not looking at adding the extra joists and the legs but this is where the guide kind of falls apart for me as reading/viewing other guides seems to suggest that only using corner supports will leave it spongy in the middle. And the amount of joist spacing also seems to differ.

Does anyone know based on these measurements what kind of spacing I need to be looking at? The guide says every 400mm which would mean 4 additional joists on each side of the deck. I'm also considering replacing the 75mm support blocks with additional legs. Necessary or no?

Davesnave

You might get more responses by posting this in "In Your Home," which is the DIY forum.

People here might have decking, especially left over from their garden makeover days, but they tend to keep quiet about it, unless there are rats living underneath.

darkwarrior

Thanks for the advice Davesnave.