I will be laying 18mm OSB/3 boards on 2 x 4 joists for a garden shed. I was planning to screw and nail them down using a mix of 50mm decking screws and galvanised nails. However, quite a few sites/videos recommend gluing the boards down too using a grab adhesive. However the choice is overwhelming.
What key label/ingredient should I look for when purchasing? I am in the UK so main consideration is atmospheric damp( the frame will be on blocks with airflow beneath the frame ). Being a shed( for storage only ), would it be problematic to skip the glue altogether?
The boards are not tongue and groove. I have read I should leave a gap between the boards for expansion and contract. Is there a recommended gap?