Choosing decking screws that last

A deck sits outside in all weather, so the screw finish matters more than the brand on the tub.

Which finish

Finish	Good for	Watch out for
Green coated	Treated softwood decking	Not for coastal sites
Stainless A2	Hardwood, oak and tanalised	Costs more per box
Stainless A4	Coastal and pool surrounds	Overkill inland

Length and gauge

As a rule, the screw should go at least twice the board thickness into the joist: a 28mm board wants a 60mm screw. Pre-drill hardwood, and use a Torx drive so the bit does not cam out when you are kneeling on it.

Browse the screws range or ring the counter if you are unsure.