Math Time

In addition to meeting with the architect and getting quotes from the structural engineers, we’re getting ready to demo the first floor. We started by removing the plaster and lath from one wall in the living room. The purpose was two-fold. It gave us our first peek at the inside of the exterior sheathing, which told us it may be in good enough shape to leave in place. We were concerned it might be rotted and if we had to replace it that would complicate our plan to use spray foam insulation.

The second purpose was to estimate how much plaster we’ll need to get hauled away. When you rent a dumpster you want to know how many yards, how many tons, and how many days. So, I filled a bucket with plaster from the wall and weighed it, getting roughly 25 lbs. Then I bagged the plaster from the one wall in contractor bags, two buckets per bag. When it was all done, there were five bags, one of which had more like two and a half buckets worth. In other words, the one wall had something like 275 lbs of plaster on it.

Here’s where it gets fun, assuming you like math. The wall is 11′ 5″ × 10′, so dividing we get about 2.4 lbs / sq ft. The ceiling is fairly easy if we fudge on interior walls, 20′ × 45′ × 2.4 lbs = ~1 ton. All of the walls are 10′, so instead of doing lots of calculations I’ll just work out linear feet and multiply the result. Front and back walls 20′ × 2. Side walls plus center wall (both sides) = 45′ × 4. For interior walls we need to add both sides of all walls, so on the larger side we have 12 × 4 + 7 × 2 and on the smaller side there are 3 walls separating the bedrooms and foyer, so roughly 8 × 6, then there’s one more wall along the bathroom that’s 7′ long, and again we have both sides. I think that’s 344.

Pure Excitement

344′ × 10′ × 2.4 lbs = ~4 tons. We had 1 ton for the ceiling, so we’re up to 5. Unfortunately, there’s also drywall on top of the plaster in a lot of the rooms, plus we’ve got all of the trim, floors, subfloor, some cement board left from the basement, and a random assortment of other crap that I honestly can’t estimate with any accuracy (how accurate any of these measurements are is questionable). Obviously we need more than 5 tons. The question is how much? It’s at least 6 tons, it’s probably 7 but is it 8? Doing the math gives us a starting point but there’s a lot of unknown.

The good news is that as long as we have an idea, we can order a dumpster for the approximate amount and they’ll charge us for the overage. As long as we have a number to start with we’re not going in blind. The fun part is that we want to have the dumpster for as short a period as possible to save money, so we have to figure out the fastest way to remove 6 tons of plaster and drywall. We’re thinking Demolition Party.