Facade board 30 mm - Frame and get thermal bridges, or not?

[Turinna]

The minimum standard dimension is 45 mm. However, instinctively 30 mm additional insulation feels very little if you calculate the potential savings in relation to the investment, but if that's all that fits, then there might not be much to do.

However, I don't think it'll be a problem to fit a 45 mm board if you align it outside the uneven frame. The advantage of "regular" boards is that they are much softer so you can compress them slightly, and they adapt to the surface. Hard facade boards will create an unwanted air gap between the board and the timber frame where cold air can find its way in.

Wow, so difficult with all these decisions and parameters... but the facade board and the studs are ordered and delivered, so I probably won't change that (although it would be interesting to compare the price and effect with regular 45 mm boards). I'll make sure he stuffs it if there are gaps…
What do you think about the minimum possible air gap, how many millimeters?

 

[EddieHansson]

Thank you, Eddie!
But you mean that 4mm is NOT enough (although you wrote that 4mm is enough) and that I should therefore add a 22x45?

Oops. Meant that 4mm is not enough. Nothing is perfectly flat and straight, so there's a high risk that a 4mm air gap will get clogged. The air gap must ventilate sufficiently to dry out moisture behind the panel.

 

[Turinna]

Oops. I meant that 4mm is not enough. Nothing is. Completely flat and straight, so there's a big risk that a 4mm air gap gets blocked. The air gap must ventilate sufficiently to dry out moisture behind the panel.

What do you consider the minimum air gap to be?

 

[EddieHansson]

What do you consider the minimum air gap?

Träguiden writes

"Note that in rain-exposed situations, vertical ventilation battens should be mounted behind the nailing battens. Minimum dimension for ventilation battens 25x48."
https://www.traguiden.se/konstrukti...-detaljlosningar/yttervagg-med-staende-panel/

But you can probably have something smaller. A fadadskiva is stiff and risks not bulging out so much.