I am new to TOH discussion boards. I hope to find lots more information here than can already be found in the magazine.
I have many questions about insulation, but I'll start with just one for now. I have no insulation in the walls in my 1920's house. I am wanting to add it...one room (or two) at a time. I plan to do some from the inside of the house and some from the outside. I have one large room in the back of the house that I wanted to start with, since it is the coldest. It has textured paneling (no grooves) on the wall. The paneling was installed over existing wallpaper, which is over original solid wood walls. The paneling was installed sitting not behind the basesboards, but on top of them. So, 8 feet above that is a seam with a molding to cover the seam. My plan was to remove the molding covering the seam, then remove the top section of paneling. After that, I would drill the necessary holes into the solid wood walls and shoot the insulation down into the bays. I called Home Depot to get a cost on renting the machine and they said they would not recommend I do it that way because the insulation will settle in about 2 years and only 1/4 of the wall cavity would be insulated. Anyway, I'll address that later. My question is this. On TOH.com, there is a how-to video of Tom Silva showing this procedure, but from the exterior of the house. He does not give a reason for this, but I wanted to know why he blows in insulation from the bottom and the top of the wall? I was thinking it was because there might be a fire block in the wall, but he states that you can plug the top hole with a rag while you are blowing into the bottom hole so that the insulation doesn't come out the top hole. If there were a fire block, then surely the insulation wouldn't come out the top. Does anyone know why he goes from the top AND the bottom? Here is a link to the video.