Next week, I am betting close to a thousand dollars that our house is full of holes I don’t know about. A crew will pressurize the house with fans and then track down where the pressurized air leaks out. Evenings and weekends for the next few months, I will crawl, climb, and wriggle my way into dark corners and dusty attics, stopping up the holes. I might even hire someone to fix the tough ones. If it all goes as I anticipate, we will get back the investment in a few years of reduced heating bills, and the cold drafts that come from nowhere all over this old house will disappear, making it much more comfortable for everyone but Napoleon, our Shetland Sheep Dog. Napoleon’s coat is designed for sleeping outdoors in the snow, so he, and he alone, is always searching for a icy draft for a nap.
When Henry Thoreau built his house on Walden Pond, he did not look for insulation to keep warm. Instead, he plastered the interior of his little house. The plaster made his cabin almost airtight. Henry was no dummy and Walden Pond is a lot colder than Whatcom County. With airtight plastered walls, even an inefficient fireplace would warm his cabin. The first requirement for warmth is walls that do not allow cold air to flow in from outside. Heat does radiate out through thin walls, but radiation is very slow compared to a rush of cold air. A well insulated space will not be warm if frigid air is flowing in from the outside.
About five miles southwest of the farm, there was a shingle mill on the Northwest Diagonal road, about a half mile south of John Schaefer’s place and just north of my great-great-uncle John’s farm. When I think of Henry Thoreau plastering his cabin, the shacks of the shingle weavers along Northwest Diagonal come to mind. Dad said once he and Grandpa came home from Bellingham after dark in the winter when the northeaster was blowing. Dad said they could see the red hot tin stoves glowing through the cracks in the walls of the shingle weaver’s shacks. Those poor people must have been cold, but if they had followed Thoreau’s practice and plastered the interior of their shacks, they would have been warm and the stoves would have been invisible.
Thoughts of those shingle weaver’s shacks prompted me to go out to yard and examine the old cedar shack that was my grandparents first house. The walls are thin– inch cedar boards– but a wide batten is carefully nailed over every gap. You could not see a red hot stove through those walls, although it would have benefited from a plastering. Those old cedar shacks are made from the same material as an Indian houses that I have seen those up close at the Royal British Columbia Museum in Victoria and the Makah Museum at Neah Bay. They used the same technique of overlapping cedar boards to seal out the weather. The Indians split their boards, the bostons, whites, had sawmills. The frame of grandparent’s shack was built from split, not sawn, timbers, so in that respect, it is like a native structure.
When my grandparents replaced the cedar shack with the house, they included the features of the day: electric wiring, plumbing, and an enormous wood burning furnace in the basement, but no insulation. They added some rock wool insulation into the north wall at a date unknown– the thirties is a fair guess.
A few years ago, we remodeled and when the crew tore into the north wall, we discovered that parts where the northeaster hits the hardest were built up from wood siding, two layers of shiplap sheathing, two by fours laid flat, wood lathe and plaster, adding up to almost four inches of solid wood. Solid wood does not have a high thermal resistance. Four inches of wood only has roughly half the thermal resistance of a two by four stud wall insulated with fiberglass batts, which is inadequate by today’s standards. But solid wood has another property: it stores heat and radiates it back, something that a fiberglass insulated stud wall does not do well at all. So the old timers knew what they were doing when they put up that crazy north wall which is warm to the touch no matter how hard the north easter blows.
This year, if all goes well, it will be the warmest ever.