Cladding battens

[Keithsmith1959]

I have constructed a timber frame wall to become a utility room, currently the outer face is marine ply. I will place a breathable membrane on this then treated battens to which I am attaching horizontal upvc cladding.
My question is should I place a top and bottom batten horizontally as well as the vertical ones and if so will they need holes in to allow any moisture to escape / breath?

 

[pred]

I think as the cladding is not 100% air tight or if you fit it upside down the water would pour in so no definitely no more holes than absolutely necessary.

 

[^woody^]

You should maintain an air cavity to allow moisture to evaporate, so you would not normally have a horizontal batten.

You should fit an insect screen at the bottom, and depending on the design at the top too

At the bottom, you need a proper drip detail to prevent water entering the bottom of the frame - a metal preformed flashing or lead which projects out from the frame and acts like a sort of sill. A minimum 15mm continuous gap should be maintained at the bottom