Loft: What size cross battens?

[garrymum]

Hi
I am about to partially board my loft for storage. Have seen several people suggesting cross battening the joists first, then laying the boards on the battens. What size battens are best to use?

Currently the joists have 600mm centres, was going to put the cross battens at 300mm centres to give it more strength. Does this seem ok?

TIA

 

[masona]

Do you have gang nail roof trusses as below?

 

[garrymum]

Not sure. Why would that make a difference to the size of the cross battens?

 

[masona]

Because the gang nail trusses are not design for loft storage flooring, although it can be done but in a difference way to the normal 4"x2" ceiling joists etc