Thunderstorms on July 21 that unleashed torrents of rain and spawned three tornadoes in southern Maine also made their mark, happily minor, on the Hedge/Roger Williams construction site.

Winds, which gusted up to 90 mph in some parts of the state, knocked over 40 feet of the fence around the site. “We called the contractor,” Portland-based Wright-Ryan, “and the superintendent was nearby, and he just came over and put it back,” says project manager Paul Farnsworth.

In non-cataclysmic construction news, the first phase of creating a steel framework within Hedge Hall is all but complete. Steelworkers have a few more pieces of steel to put in, and then it’s just a matter of squaring things up and tightening the bolts, says Farnsworth.

This steel is supporting the structure up to the roof. The next batch of steel for Hedge will support the roof itself, but that won’t happen for a while. In fact, the next steel shipment, due during the second week of August, is bound for Roger Williams Hall.

Also at Hedge, work continues on the foundation for the addition that will face Alumni Walk. Inside the building, workers will drill the hole for the hydraulic piston that will lift and lower the elevator. This requires dangling a chain down inside the new elevator shaft to bear the weight of a big hydraulic drill that will bore the 14-inch-diameter, 39-foot-deep hole.

Over at Roger Williams, masons are reaching the end of the brick work — cleaning and repointing — that has brightened up the building’s facade. (Staring at the spiffed-up walls one morning, Campus Construction Update was pleased to notice, for the first time, decorative courses of Greek key and rope masonry that hadn’t previously been so apparent.) The north and final wall will likely be done by the end of next week.

Speaking of bricks, if you pass the Bill on the east side, by New Commons and Alumni Gym, look closely at the wall. Toward the left, near where the windows have been filled in, look for two slits that have been cut from ground level to the roof.

Once the interior has been shored up, Farnsworth says, that section of wall will be taken right out. Similar to what happened at Hedge, the opening will provide access to an addition.

Farnsworth adds that the folks who build with concrete blocks on this project are all but done. Their last bit of work is on the elevator shaft, which needs just a few more courses of blocks under the roof.

Progress is progressing on the old foundation of Roger Williams. On the inside, the last of the “one-sided walls” — actually a new layer of concrete applied to reinforce an existing wall — was poured this week. Outside, the next couple of weeks will see the end of the dampproofing, drainage work and concrete spraying that will prepare the foundation for the next 50 or 100 years.

Notes from Underground: At Roger Bill, watch for the removal in early August of asphalt pavers on the New Commons plaza near the 1910 Gate. Workers will be excavating for a drainage line that will link to a vault in front of Alumni Gym.

Just behind the fence next to Alumni Walk, a long stretch of new steam line is being welded up. It replaces a line that was in the way of the Hedge addition. The pipe links to a new steam vault at the east end of Hedge.

Also in the world of campus steam, installation of the replacement line between Hedge and Ladd Library should start next week. The pit across the service road will be large, Farnsworth says, to accommodate water and telecom conduits too. The road is closed to vehicle and pedestrian traffic until Aug. 20. Take Alumni Walk or the stairs under Ladd if you need to cross campus east or west, Farnsworth advises.

Two old abandoned steam lines at Roger Williams, in the meantime, are coming out, a process necessitating asbestos abatement. And the campus’ very oldest steam line, in case you were wondering, has also been consigned to fond memory. Scheduled for September completion, workers are replacing this pipe that connects Lane and Pettigrew halls — hence the recent commotion near Lake Andrews.

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Read this week’s news about the Garcelon Field renovation.

These days, the renovation of Hedge and Roger Williams halls seems to be all about the concrete — taking it out and putting it in.

In Roger Bill, it’s been coming out. Workers have pulled out chunks of the basement floor to make way for new plumbing and to cut openings for 19 new footers that will support the building’s new interior steel framework.

But wait a minute — the footers will be concrete, too. Replace concrete with concrete?

Say, what’s the big idea? we asked project manager Paul Farnsworth. He explained that plain old basement-floor concrete isn’t strong enough to hold up the steel (and thereby the building). So the footers will be reinforced with those ridged steel bars called rebar.

“The footers distribute the point load of the steel over a wider area of ground,” Farnsworth said.

Over at Hedge, meanwhile, the concrete was flowing left and right. So-called shotcrete, or sprayed concrete, was applied to the outside of the eastern foundation wall. That created a nice smooth surface for dampproofing — that being the black stuff that you could see if you stood on a soapbox, peeked over the fence and looked at the foundation wall that faces Ladd Library.

The same work will soon be done to Roger Bill, with a trench all around the foundation providing access.

Concrete was being pumped inside of Hedge this week, too. Some of it went into the same kind of footers, of which Hedge also gets 19. But some concrete went inside to form something that reminded Campus Construction Update of a Zen Buddhist koan. This “one-sided wall,” Farnsworth explained, is a new layer added to the vertical plane of a wall.

“Essentially, we use the existing wall as part of the form” into which the concrete is poured, he said. “They really just made the wall thicker, and of course there are rebars and such in there that tie the old foundation to this new part.”

Above ground level, Hedge looks like a mere husk of its former self, with nearly all its windows gone and a gaping hole on the north side. Its appearance will get worse, too, because most of the roof will soon come off. We asked Farnsworth what all this exposure to the elements means for the building’s interior.

Interestingly, not that much. The biggest concern is protecting the historic brick as the roof is removed. “They’ll cover it so we don’t flush water down into the brick,” he said. “The other stuff is no different from if you were building a new building and rain gets on it.”

Meanwhile, although you won’t see it for a few weeks, there has been progress in obtaining the steel that will ultimately hold up these buildings and their heavier new roofs. (The wall bricks have done that job for the past century.)

Before anyone actually lays a hand on metal, a steel fabricator needs to interpret the architects’ design. “The fabricator has an engineer and they actually do the measurements,” Farnsworth explained. “They’re told what sizes they need by the architect, but for all the exact lengths, they have to survey and create lengths to meet field conditions.”

The steel fabricator makes a set of drawings that are submitted for checking to the engineer of record, Becker Structural Engineers, Inc., and the architect, which in this case is JSA Inc., of Portsmouth, N.H. The drawings created by Northland Steel Corp. of North Reading, Mass., for Roger Bill, and United Steel Deck, Inc., of Summit, N.J., for Hedge are currently in final review.

“We’re thinking that in June, the stuff will show up on site and they’ll start putting it together.”

Notes from Underground: Watch for some gas-line work in the next week or so between Hedge and Ladd Library. A line currently running in front of Hedge — that is, on the Alumni Walk side- — and feeding Dana Chemistry is in the way of the forthcoming Hedge addition and will be rerouted around the south side.

“So at some point there will be a one-day event where we dig a trench and Unitil, the gas people, puts down a new pipe,” says Farnsworth.

Can we talk? Campus Construction Update welcomes your questions and comments, unless they’re mean, about the Hedge-Roger Williams renovation project. Please e-mail staff writer Doug Hubley at this E-mail, stating “Construction Update” in the subject line.