Insect mesh and air gap for timber cladding?

[Great_scot_selfbuild]

Question for those who have installed (or had installed) timber cladding…

 

I know we need an airflow behind the cladding, and because we need to fit our shingles onto horizontal battens, we have vertical battens followed by counter-battens.

 

I’ve 2 questions:

 

1. How large does the gap at the bottom and top need to be?
2. What have you used for the insect mesh at the bottom and top?
3. Does it matter if the top and bottom of windows doesn’t have a gap? 

 

Around the windows, our builder has installed double-thickness battens, which is good for the fire stopping, but limits airflow - however, because we have counter-battens, there is still airflow laterally and the windows don’t cover the full wall, so does this still meet the requirement?

[Dunc]

Our air gap is defined by the counter battens - 22mm. 

I used stainless rodent mesh 8g from Robinson wire cloth - more worried about mice than bugs round here. 150mm x 30m rolls worked well.

I did try keep some gap around window head and cills but with the way it went together its probably onlt 5mm at best. Like you, I trust lateral movement of air will be sufficient. 

https://timberdevelopment.uk/resources/the-timber-cladding-handbook/

Worth a read.

[Owain1602]

I’m not sure if your picture is up to date, and reflects the words, but I can’t see double thickness battens around the windows for fire stopping?

You need infill battens between your horizontal ones to act as a cavity barrier.

 

Except for the obvious ventilation requirements, the thing that was always in the back of my mind when doing the detail for ours was any water running down the cavity above a window. I didn’t want a surface where this water would sit on, and potentially start migrating back towards the head of the window (or sit on a batten constantly). Might have been overly cautious, but I’d rather that than the other way around.

The water could be condensation, wind driven rain etc.

 

Cladding suppliers I have used previously typically want at least 10mm gap at the top and bottom of the cavity.