Archive for December 16th, 2006

John the Mason is back and brought along his friend Rufus. Ted keeps them supplied with brick and fresh mortar. Making the transition from 50 year old brick to new brick unnoticeable was the single biggest technical fear I had before starting this project. My old brick has a range of colors, which helps, and John was able to find a pretty similar mix. We also kept a good supply of the old brick from the demo phase to weave in along the transition line.

Of course you can't weave in new mortar - it's a stark old-new vertical line - so getting that right is particularly critical. I compared several mortar color samples, which is routine, but also pressed that the sand (which is 75% of the mortar mix) match the original as close as possible. This is probably not typical (John made this point quite clear), but is a technique I've read about numerous times in preparing for this project. I dissolved old mortar pieces in muriatic acid, washed and dried the resulting sand, and compared it with local supplies. Ultimately I had to buy almost 2 tons of white play sand to mix in with our pinkish local sand to get the right match. This was one of the very few times that John and I have butted heads on this project so far, but masonry is permanent and public. In the end I think we were all happy with the results.

This wall had some challenges. First of all there was no room for the required air gap between the brick and the interior framing. That appears to have developed from a mistake by John and Ken while laying the sill plates before framing. Then the framers, not realizing this problem, made a couple of decisions that resulted in the wall being neither parallel nor plumb. The errors were just a few inches but that's enough that the masons need to account for it as they build each course up to the soffits. I was impressed with how seamlessly they were able to do this and its now impossible to tell there was ever an issue.

The lack of an air gap behind the brick was an unacceptable condition and there didn't seem any obvious solutions at first. I did some research and worked with our architect and John to come up with an alternate wall section that didn't require an air gap. That's why there is thin pink insulation board under all the brick. Under that is a polyethylene vapor barrier and under that is the OSB sheathing. Again, this was more challenging for the masons because their mortar couldn't ooze out the back. They did a great job, though.

In this last picture you can also see the new basement door and the new large windows in the old bedroom above. The dormer windows are large horizontal sliders.