Having spent many hours in the attic, I knew our old insulation was insufficient at best. Coupled with that was the fact that the second layer had disintegrated into a fine powder. Whenever I needed to do some work up there, I could guarantee that I would come back looking like this:
like Bert the chimney sweep (Dick Van Dyke) in Mary Poppins only without the smile. Additionally, this insulation dust would continuously migrate down to the first floor making it futile to keep the house clean (or at least dusted). So Carmen and I took a long holiday weekend and some cooler than normal weather to begin the demolition and clean-out phase.
In my December post I also said I would show how I modified the rafter areas the create a continuous air channel that runs between the roof deck and the insulation. Many will say that it is overkill, and I would tend to agree. However, I am the kind of person that prefers to do things once and am fond of overbuilding to make sure I achieve this goal. And given the fact that once this insulation is in place, there is no modifying it without the need to completely redo it. So, here is a diagram of what I did:
This is a photo showing the actual installation:
The hope is that with a continuous air stream running directly underneath the shingles, the heat load will not be allowed to build where it causes the temperature in the attic to be drastically different than the first floor. The other issue came to warranty of shingles. I remember when I was researching foam insulation before we did our exterior walls a few years ago, many shingle manufacturers where not warrantying their shingles if foam insulation was sprayed directly on the back side of the roof deck. This may have changed since some of the roofing manufacturers have gotten into the spray foam arena (Owens Corning in particular).
In the end, I can sleep easy not having regrets that I should have done this or that. If things turn out that this effort wasn't really worth all of the work, then so be it. At least I will know that I did everything I could to make this space comfortable.
Finally, the one project that had eluded me until right before the insulation was sprayed was the rewiring of our doorbell. Why is it that something so easy turns out to be one of the hardest things to complete? Before we had our exterior walls insulated, I tried to run a new doorbell wire to replace the existing wire because it had been cut in half prior to us purchasing the house. Long story short, the remaining wire snapped off in the wall as I was trying to pull the new wire through and I was never able to run a new wire. Even after carefully removing the trim around the door, I could still not locate the wire in the attic. After working three hours and boring a new hole through the wall, I had success in getting the wire upstairs. Just don't ask me how long it is going to take me to get the door bell functioning.