4.8m x 4.8m decking

[jamesa2487]

Hi all

I have just started a decking project. It is 4.8x4.8
For the outer frame one side is attached to a brick wall and the rest I have put concreated posts in.

I am running 4.8m joists at 400mm centers so total of 12 including the two edge ones. The bit I'm stuck on is how many posts do I need for this?

I can provide a rough drawing is that will help but I am thinking along each 4.8m joist to have 4 posts (one every 1.6m) but do I need to do that for every joist as they are only 400mm apart .

Thanks

 

[r896neo]

If you have the ground clearance its often easiest to use a joist underneath and perpendicular to the main joist and bolt it to the posts which then only need to be every 3/4 4th joist.

If you don't have the clearance for a bearer like this i would support every joist.

 

[jamesa2487]

Ok. I do have enough ground clearance to put a 4x2 under the joists so if I did a post every 3 joists so every 1200mm then attached a joist under this should be fine?

So ignoring the perimeterthat would be 9 posts Inside the outer frame?

Only other thing is I will be attaching the bearer to the side of the posts. Can I just use screws for this or do I need bolts?