Expansion gap on tongue and groove garden gate

[Adam78]

I'm building a garden gate using pressure treated tongue and groove boards that 15mm x 100mm and nailed down using round galvanised nails.

How much of an expansion gap should I leave between the boards?

Should they be fitted tight or do you leave an expansion gap.

 

[big-all]

Depends on design off gate but i allow 2mm between planks iff ultra dry and a 12mm all round the the edge with a 19-25mm gate stop
as an aside
15x100mm planks will be perhaps 12mm thick and 88mm coverage, so keep this in mind

 

[Adam78]

Depends on design off gate but i allow 2mm between planks iff ultra dry and a 12mm all round the the edge with a 19-25mm gate stop
as an aside
15x100mm planks will be perhaps 12mm thick and 88mm coverage, so keep this in mind

gate is a ledge and brace design