Hello.
I'm building a garage at the moment where I will have an upper floor. It has framework trusses, so I will get knee walls. The knee walls will be cold.
I do not want an air gap under the sheathing on the knee wall, as I want to be able to inspect the sheathing (notoriously afraid of mold). The air gap will therefore start at the vertical wall that will be the inner wall on the upper floor.
The air from outside will be taken from the eaves which will be clad in molding.
See image below
A: fascia board
B: molding (sealed)
C: air gap, intake air for ventilating the sheathing
D: weather barrier
E: insulation
F: air gap sheathing
G: possibly a board??
Now to my question. The weather barrier will go up to the molding, the eaves will be clad except for the air opening "C" at the outermost part. From here, air can then find its way up to the air gap F.
My concern is whether I should place a board "G" that goes from the end of the weather barrier and reaches up to a few cm below the sheathing, so I create an additional "air gap."
I'm not quite sure how it's usually done with framework trusses.
My own thoughts on the matter:
Snow cannot enter the knee wall with board G. However, the question is how much snow will enter through gap C. Hardly any, I guess.
Installing the board G makes the "molding" box impossible to inspect without unscrewing the molding. If I don't have a board, I can do any maintenance/check from the knee wall.
Without board G, I might get "too windy" on the knee wall. However, all the air still has to come in through gap C, so it feels like a weak argument.
So what do you say? Should I install a board G or skip it?
