Installation advice for 18mm t&g loft boards needed

[ch4chi]

Hi, i am looking to lay the 18mm tongue and groove loft boards into the lift space, just wanted to ask do the ends of the board have to meet on a joist and be secured into the joist or can the joint be floating away from a joist?

If the joint should be on a joist do I cut the lip and make it flat edges that butt up to one another or just screw into the tongue and grove joint through to the joist?

Please advise, thanks in advance.

 

[alan333]

The joints can be anywhere if the tongue and groove is properly seated. Think of all the side joints - they're unsupported.

 

[chickenlips]

The joint of the board can land anywhere, but any unsupported joints (over 75mm) must have a noggin to support it.