Underlay Orientation

Which way should the underlay go in relation to the laminate flooring?
Is it 90 degrees?
Ta

 

Won’t matter mate

 

Lay it diagonally

 

As above, no major issue but you can do it 90 just for piece of mind

 

If you lay it 90 to the flooring, then the seams cross a lot more joints and every run. If you were to lay it with the flooring, there's a good chance the seaming only touching a run on the short end joints every so often. It seems like it would limit potential issues.