Saturday, December 31, 2011
Some Exciting Scaffolding
This house that I've been working on the last two months was originally built in 1769. The roof was all saggy and sloped and there were ice dam issues last winter. As we pulled off the shingles (to keep the weight down on the 6x6 rafters joined at the peak with only pegged bridle joints, joined to the sill with only a step lap and a peg) we discovered that whomever re-roofed this last (sometime in the last 20 years I believe, shortly before the current owners moved in) they didn't even use tar paper. Ice dam issues are really an issue that comes from keeping warm air from getting to the surface of the roof, melting the snow, and letting it run down to the gutter where it re-freezes into ice, building up and working under the shingles, melting again and dripping into the house. So if you have an ice dam, step one is to add more insulation and air-blocking between the house and the attic. If that's not an option, or you're looking for a quicker fix, you can use something like Grace brand roof underlayment, essentially a sheet of rubber with super sticky tar on the back. This stuff clings like crazy to plywood, seals any places water can get in (when applied correctly), seals around nails, and keeps any water that can get through from migrating. We have frequently stripped the bottom three or six feet of a roof to apply the underlayment and then re-roof that part.
In the case of this roof, it was so badly sagged and wonky we decided to strip the shingles and create a new roof plane. This house is big and tall, with the field being about 37 feet long and 20 feet up the rake, with roughly a 12 pitch (45 degrees). We pulled off the old trim around the two rakes and the drip edge, replaced with all new trim built up to more appropriately suit the scale of the house. We then strung a line on the ridge, which created four edges of a flat plane. Using vertical strings, we blocked and shimmed horizontal battens into a nice base for new 1/2" plywood. With that done, underlayment on, and shingles nailed solidly down, it's done! At least until spring when we tackle the back half.
This house was really neat to work on. When we opened up the trim, I was fascinated to see that the ends of the floorboards were all trimmed to length with an axe. Most of the timbers were hewn, and it was interesting to compare those hewn by novices and those by the experts. It was also interesting to see how much some of the rafters had twisted and moved, one in particular was twisted almost 45 degrees from end to end.
I've never really liked heights very much, but over the last two or three years have become more comfortable working at moderate heights through practice. In dangerous or really high places we wear safety harnesses and fall ropes, but they always get in the way and in many cases I feel that they make the situation more dangerous. Starting this project, which was particularly high and steep compared to many of the houses we work on, we were both really quite uncomfortable even walking around on the scaffold. After a couple of weeks though, we were regularly playing catch with sawzalls, sheets of plywood, dashing up and down the ladders with hardly a care in the world. Heights, though potentially a very real danger, are largely a mental block. Once you can get comfortable, it is much easier to focus on the work and actually get things down in a timely manner. If this roof had been on the ground, and especially without the need to manage the lead paint, we could have had the whole thing done in a week. As it is, though, it took about 150 hours spaced out over two months to accommodate the weather (which was thankfully quite mild this year).