Hey everyone, Brady here. I am remodeling an old balloon framed home in North Texas and I have a question regarding the current siding material/weather barrier. A little background on the house. Balloon framed, no insulation anywhere, half the houses siding is a concrete/stucco looking material, while the other half is cedar siding. There isn’t any exterior sheathing. Cedar shiplap is on interior walls and ceilings. 

I have air sealed the crawlspace and currently attacking the insulation of the exterior walls. For the cedar siding, I am planning on using felt (air gap) and spray foam. But for the concrete siding, I’m debating on if I need the felt or if I could foam directly to the weather barrier (pictures below). Any information of the concrete material you think this is and how I should attack the insulating of the wall would be greatly appreciated!