Recently, I had the occasion to pull off the plaster in a bathroom only to discover that the insulation did not fill the available cavities and even worse, the biggest gaps were at the top where the heat is trying hardest to escape. Keep in mind that I live in Minnesota where outdoor temperatures reach at least -30°F a couple of times a winter. The ONLY way to stay warm in a house with such a crappy insulation package is to run the furnace at full output and hope that that is enough. If natgas weren't so cheap, no one could afford to be that stupid / careless.
My absolute favorite example of shoddy workmanship is in the cavity to the right of the window. The insulation batt had to narrowed so it lost one side of the attachment mechanism. So the installer just held it in place with a roofing nail. Then, because the top row of the exterior sheathing had been skipped, the batt just flopped out into the overhang cavity. (to see the captions, click on picture to see full size)
With all the insulation removed, it becomes clear that the gap in the exterior sheathing continues to run all the way around the house. This means that in the majority of places where the wall meets the ceiling, the only barrier between the inside and outside is the layer of plaster.
Lot of lessons to be learned from this example:
- This example is far from rare. In fact, when Xcel sends the energy bills, it ranks our house against others in the neighborhood and we are usually in the top 25% for energy efficiency. Look at this mess and wrap your mind around the fact that 3/4 of the housing in the area is WORSE.
- Problems like ours do NOT have simple solutions. Correcting our mess requires far more than drilling a few holes and pumping some expanding foam into the cavity. If this problem is solved from the inside, it requires that all the plaster and interior trim must be removed. If solved from the exterior, all the siding must be removed / replaced and the whole moisture barrier / infiltration control system must be re-engineered.
- There are reasons for shoddy insulation. Installing it can be very unpleasant. The job is usually given to the lowest guy on the totem pole. It becomes just another task to finish as quickly as possible. Worse, architects take 50 times as much time selecting the bathroom tile than designing insulation systems and rarely design sufficient space for them.
Now if real estate were priced rationally, the case for repair / replacement would be stronger. For example, our house cost about $15,000 new in 1958 and 56 years later, wear and tear should have reduced the market price to about $1500. At that point, a $40,000 insulation upgrade would be doable.
Fortunately, the majority of the costs of a serious insulation upgrade are in the design and skilled installation areas. The insulation itself is pretty cheap. So any homeowner willing to spend the effort necessary to upgrade their skill sets can do this. So economically, it CAN be done.
Now for the sake of the planet, we can only hope that the Instincts of Workmanship are more widespread than at first glance. And so to our friends who think that carbon emissions can be reduced by marching in the streets, please go home and learn to do something useful.