Honor system

Posted on 8 June 2013

I have the pleasure of working with some really great people.

Today, we were in the final stages of pre-demolition work on a large renovation project. A couple of folks from Castle Electric, my usual electricians, were on the job yesterday pulling light fixtures and generally making the place safe for the guys who will be taking down the plaster next week. I had asked them to be careful with a number of the fixtures so that we could donate them to the Reuse Center. This morning I found a collection of fixtures ready for new homes along with this note:

Broken light fixture with note in apology

Categories: trade secrets, Uncategorized

Tagged: Castle Electric, Electrician, light fixture, Reuse Center

Housemates

Posted on 3 June 2013

As I was coming home the other day, I was puzzled to see what looked like mildew on the casing of my front door. I’m not immune to such things, but there hadn’t been any in the morning, and it wasn’t a particularly humid day. I got closer and realized that the new life forms were much higher on the evolutionary ladder. It seems there’d been a hatch of little spiders during the day, and some had taken up residence in the space beside my storm door. I checked in with a couple of bug-savvy friends (this happens more than you’d think), and got the unanimous ID: Araneus diadematus, the Cross orbweaver, a common late-summer garden resident.

And just so no one thinks the entomologists have hijacked the blog, the storm door in the image above is made from Spanish cedar, and the primed door casing (no, nothing on my house is ever done…) is sapele. For scale, the door reveal is a heavy sixteenth.

Getting a little closer:

That’s a dime, again for scale, in the image below.

Categories: entomology

Tagged: Araneus diadematus, Cross orbweaver, Roslindale, spiderlings, spiders

Glass magic

Posted on 26 December 2012

One of the key fringe benefits of my work is getting to see other trades at work. And the very best part is seeing the brilliant, magical techniques that other tradespeople regard as completely routine.

The other day I had to pick up a piece of laminated glass from Sarno Glass and Mirror in Hyde Park, MA. We were making a door for a medicine cabinet (for the third time, but that’s another story), and we needed to use safety glass so that a slipping client wouldn’t bump into the cabinet, break the glass, and sever an artery. There are two kinds of safety glazing — laminated and tempered glass. Tempered glass is a pain, as it has to be cut first, and then tempered in an industrial oven; there is often a significant lead time. John Sarno suggested instead that we use laminated glass — two sheets of normal glass sandwiching a layer of tough plastic — since he had it in stock and could cut it to size right away.

When I arrived at the glass shop to pick up the piece, I realized that there had been some miscommunication, and the piece that was ready was thicker than I needed. This turned out to be a very fortuitous mistake, at least from my selfish standpoint, as I got to watch the new piece being cut. There are many things I take for granted, and it seems that cutting lammy is one of them. Here’s the complication that had never occurred to me: you can cut each side of the sheet normally with a glass cutter, but how do you cut the plastic in between? Here’s the deal:

Cutting the first sheet with a normal glass cutter

Using a normal diamond-wheel glass cutter, he’s able to score one side of the laminated glass sandwich, and then with very careful downward pressure, snap that sheet without shattering the other side. Then he flips the sheet and repeats. I’ve done this sort of glass cutting myself, but the pros do it much more elegantly. Notice, for example, the brass holder that supports the L-square near the bottom of the image — it’s attached to the glass with a little suction cup! I always struggle with the straightedge slipping on me while I’m cutting; now I understand.

But now that he’s got both sheets of glass scored, things get more interesting.

$Pouring denatured alcohol into the fracture$

Pouring denatured alcohol into the fracture

With a handy squeeze bottle, he floods the surface of the glass with denatured alcohol. Then, flambé!

Setting the alcohol alight

He lets the flame grow, and then starts gently flexing the piece of glass up and down.

Flexing the sheet to stretch the heated plastic layer

As the flame warms the plastic layer between the sheets of glass, the plastic softens enough that he can stretch it a bit by flexing the whole sheet up and down. And the flame from the alcohol isn’t hot enough to cause a thermal shock that could break the glass. (The astute reader will notice both a baseball and a border collie in the photo above. To the best of my knowledge, OSHA frowns on the presence of either in a glass shop.)

Cutting the plastic layer with a razor blade

Now that the plastic has been stretched, there’s just enough room to fit a single-edged razor blade into the gap to make the final cut.

Categories: trade secrets

Tagged: alcohol, cutting, fire, Glass, Hyde Park, laminated glass, Sarno Glass and Mirror

Collateral damage

Posted on 6 November 2012

We were using West System epoxy to repair a window sill when we ruined the day of this dragonfly. It was identified by an entomologist friend (everyone needs one!) as an Autumn Meadowhawk, Sympetrum vicinum.

An unlucky Autumn Meadowhawk stuck in our epoxy repair

A closer view of the unlucky dragonfly

Categories: entomology

Tagged: Ashmont Hill, Autumn meadowhawk, Dorchester, dragonfly, epoxy, Sympetrum vicinum, victorian, West System, windowsill

Don’t need no stinkin’ OSHA

Posted on 7 October 2012

Who knew!

(Just to be clear, this is not one of our jobsites…)

Categories: trade secrets

Tagged: ladder safety, Roslindale

Winston banished

Posted on 21 September 2012

We try to balance the needs of woodworking and metal fabrication in our shop, but sometimes the metal worker gets sent out to the porch in front of the shop.

Categories: Shop work

Tagged: metal working, shop, Winston Braman

Annals of Forensic Carpentry, Vol. 2, No. 1

Posted on 18 September 2012

Winston, my co-worker, arrived at the job site a few minutes before me, and called because he thought he was in the wrong place. “I thought we were looking at a rotten porch. The place I’m looking at is new construction.”

The triple-decker condo building in Jamaica Plain was completed in late 2005, but one of the owners called me recently to look at problems with the rear decks.

The first sign of problems was the brown staining on the white ceiling — visible if you look closely at the second floor ceiling above. Then the client showed me some of the failing deck boards.

and up close:

In one location, they had replaced some of the decking, but the replacements were now failing as well (with Musti for scale):

Soon the cause, if not the extent, of the problem started to be clear. The builders had framed the decks without any pitch to promote drainage. Furthermore, they had installed tongue-in-groove fir decking over plywood (see photos below) on the deck surface and plastic imitation-beadboard ceilings underneath. All of these details combined to create a chronically wet state inside the floor system: Water falling on the deck tended to stay in place, saturating the fir and plywood, and anything that dripped through got trapped by the plastic below. Not so good.

What we should have seen is something like the following:

In this arrangement, the deck framing is sloped away from the house, and there is a rubber roofing membrane covering the deck surface and dumping into a gutter. A walkable decking material is installed over sleepers (framing members which sit on top of a lower surface) which rest on the rubber. The sleepers can be tapered so that the uppermost deck surface can be level. Square-edged decking boards, installed with gaps between each board, allow water to drain to the rubber roofing membrane. In this installation, decorative boards can be installed on the bottom of the deck joists to provide a finished ceiling below.

A simpler design would also work:

In this case, there is no sloped framing and no waterproof roofing membrane. Instead, square-edged decking is installed with gaps between the boards (we like 3/16″ — not so large as to kill wearers of high heels and not so small that leaves would clog the gaps). Water drains straight through the deck to the surface below, so no finished ceiling is possible, and the deck doesn’t afford any weather protection to the level below. But there is no opportunity for water to collect and cause mischief.

In the case of the JP decks, mischief happened. The t&g flooring and the plywood underneath it trapped water, and because the fir decking is not naturally rot-resistant, it started to fail 5 or 6 years after it was installed. The generally wet conditions also promoted rot in the pine trim boards.

Pine riser, seen from below:

Skirt trim at base of deck:

Our next step was to investigate whether the chronically wet conditions had compromised the structure of the decks. We removed the plastic “beadboard” on the ceilings at the first and second floors to reveal the deck framing. The good news was that the floor joists were made from pressure-treated lumber, and that they were still in good condition. However, the joist hangers and lag bolts in the ledger were significantly corroded.

The moisture inside the deck floor system likely contributed to the corrosion, but another factor was likely more important.

For many years, the preservative used to treat outdoor wood was chromated copper arsenate (CCA). Concerns over potential toxicity of any arsenic that might leach out of the wood, though, led to the phase-out of CCA. Starting in January 2004, the US EPA mandated that pressure-treated wood used in residential settings be free of arsenic. In New England, the predominant replacement for CCA has been ammoniacal copper quaternary salt (ACQ), a combined fungicide and insecticide.

But the law of unintended consequences is a harsh mistress. While ACQ is an effective wood preservative, it turns out to be dramatically more corrosive that the preservative it replaced. ACQ contains much more copper than CCA, and the copper is more readily soluble in water, setting up perfect conditions for galvanic corrosion to set in. Aluminum and steel are particularly vulnerable, with zinc somewhat less so. The upshot was that builders soon observed their nails, screws, and hangers turning into powder when in contact with the new pressure-treated wood. The photo below shows a particularly dramatic example of galvanic corrosion from the same deck. Steel nails installed through copper flashing have completely disintegrated, along with sections of the flashing.

It seems that the company that produces ACQ was aware of the corrosion problem, but the information was slow to reach many carpenters. (Framing lumber, after all, rarely comes with an instruction manual.) The corrosion potential can be successfully managed with triply-galvanized joist hangers, epoxy-coated screws, and stainless steel bolts, all standard practice in 2012.

The deck in question, though, was built in 2005. When I examined the joist hangers, I could see that they were not the extra-galvanized variety now in common use (Simpson Zmax). The high moisture levels resulting from the faulty construction, combined with the extra copper in the ACQ, overwhelmed the thin layer of zinc on the hangers. We consulted with a structural engineer who indicated that all of the hangers, along with all of the lag bolts in the ledger, would need to be replaced immediately.

There was one bright spot in our investigations of this deck: It seems that the builders were careful in flashing behind the deck ledgers, and the sidewall of the main structure looks like it has remained dry.

We are now working with the owners of the building to determine the best way to modify the decks to ensure their safety and longevity. Stay tuned.

Categories: Annals of Forensic Carpentry

Tagged: ACQ, CCA, deck building, galvanic corrosion, Musti, pressure-treated lumber

19 years of iteration…

Posted on 14 September 2012

19 years worth of my phones

and conversations are still garbled. I got my first mobile phone, a Nokia 101, in 1993 and tried not to use it at all, as the minutes were very dear. I gave up on it after a while, and didn’t get on the carousel again until the oughts. Twelve phones in the last twelve years, and I still wish I didn’t need one, though I spend an inordinate amount of time with the current one.

I documented the group as #s 2-12 were headed off to the recycler.

Categories: History

Tagged: cell phone, communication, Nokia

Interview with a kindred soul

Posted on 10 September 2012

I’ve wondered for a long time about the economics of doing skilled hand-work. Adam Davidson of Planet Money does a nice job addressing this question in one contemporary context in his recent story on NPR. I suspect that the story generalizes; it certainly resonates with our experience. Has it always been this way? I’m curious about the social and economic standing of cabinetmakers and joiners working 200 years ago in Massachusetts, for example. Were they roughly in the same social class as their customers? And could they afford their own work?

Categories: History

Tagged: bespoke tailor, economics, NPR, Planet Money

Found in the attic

Posted on 6 September 2012

One of the perquisites of my work is getting to poke around in the attics and basements of old buildings. Along with mummified squirrels and decades of dust, weird and elegant things occasionally pop up.

Last weekend I was helping my friends Anne and Paul evaluate the wisdom of buying a particular 2-family house in Arlington, MA. The house was unremarkable, but the attic had a couple of treasures:

These two wooden toilet tanks served the first and second floor bathrooms. They were reportedly located in the attic to ensure that there was enough pressure to clear the un-optimized bowls of 1913.

The house also had the most elegant retraction mechanism for an attic stair I’ve ever seen.

There were a pair of lead counterweights attached to a rope with a double pulley arrangement and then to the ladder. The ladder rode on a steel roller:

It worked just as smoothly as you would hope.

Categories: History

Tagged: Arlington, attic, attic stair, toilet tank, wooden plumbing