The dust is flying at LP High as renovations kick into summer gear – LaSalle News Tribune

The brick walls of La Salle-Peru Township High School are covered in mortar dust.

Last week was ceremonial hammer time when the school broke glass on a fake school window to kick off the project. Now, reality hammer time is underway as students have left for the summer and the schools $38 million renovation project accelerates into high gear.

Bricks in the wall

A drive-by glance might tell you the brick looks good for another 100 years. Standing and watching workers tuck-pointing the mortar, with a construction superintendent pointing out details, changes everything.

A lot of this looks good but for maintenance and the life of the building, there is water intrusion in there, said Jerry Kunzer, site superintendent with Pepper Construction, Barrington. This water intrusion has become visible inside, said Matt Baker, school spokesman.

The tucking and pointing

The mortar and brick work is the most visible, and audible, labor going on now. Workers are using grinding wheels to remove old mortar, which will be replaced with new mortar, a process called tuck-pointing, sometimes known as re-pointing. Some bricks also will need replacing. This work started before school let out in late May and will continue into August. The contract for tuck-pointing and masonry restoration went to Evans-Mason Inc., Springfield, for $908,883.

What theyre basically doing is grinding out all the joints, the horizontal and the head joints, Kunzer said.

Its called tuck-pointing, where new mortar is tucked and pointed into a groove made by a grinding wheel, Kunzer said. The circular grinding wheels run easiest along horizontal joints, but its trickier between short, vertical ends of bricks. Here, the wheel leaves half-moon grooves in the vertical seams. If the worker grinds too far up or down, the wheel touches the brick, a no-no. So, workers have to finish this joint by using small, chipping tools.

The crew is shooting for a three-quarter inch recessed groove where mortar needs replacement. Kunzer pointed to an area where mortar has been removed, revealing gaps and holes in the original mortar.

You can see as you get in here, theres some holes back in here. You get more of that on a head point than you do on the horizontal. Thats what that tuck-pointing will help take care of. Theyll get this tucked all the way back in there and that helps stop any water infiltration, he said.

This problem stems from basic bricklaying. The wet mortar lays better on the horizontal joint with the help of gravity. The vertical mortar must be pressed to the ends of bricks, as gravity wants to pull it off.

Because when theyre using their trowel and theyre putting it on the head joint, sometimes it falls off, Kunzer said.

Kunzer is toying with calculating the total feet of mortar joints across the entire exterior of the school.

We have an intern coming out in the next week or two. I was going to challenge him, he said.

Counter-weighted swing stages

On a large area of flat wall, three workers stood on a scaffolding platform, specifically a swing stage, held by cables attached to counter-weighted booms on the roof. The cables run through motorized pulleys so the stage can move up and down. The workers start grinding near the roof edge and work their way down. On a nearby roof edge, three more workers looked down on the wall.

I think theyre trying to figure out where to move the swing stage to next, Kunzer said.

The three workers on the stage were grinding mortar into clouds of white dust. They wore breathing masks. Pulsating vacuum hoses attached to the grinding tools sucked up some of the dust.

Every person on that swing stage is required to have a full-body harness, and thats tied off to a separate structural point, Kunzer said over the grating buzz of grinding.

Other walls, like the ends of the south wings, have complicated cornices and pilasters and will not allow a hanging stage. Here, a worker on a hydraulic lift grinds away the more convoluted mortar joints.

Matching colors 1927-1963

It is a challenge to match new mortar and bricks with old materials. Mortar takes on the color of the sand it contains, and brick is colored by the local clay used. The school includes Streator brick from the 1920s.

A test site has been set up on the northeast side of the main building, the exterior of Matthiessen auditorium, which was tuck-pointed in the 1990s, Baker said.

Were not sure what they used originally, Kunzer said. Theyre trying to come up with a color and texture sample. Right now were doing a lot of the grinding until we get all the mockups approved on the mortar samples. As were doing this, there are several areas where the architects are trying to match the old 1927 brick because of the additions. There is a 37 and a 63 where its a different brick. This addition here was 1963. Theres a 1937 in back of it. You can see the difference in the brick colors here.

The brick layout is different between additions. The oldest part alternates full and half-brick pieces, what is called Flemish bond pattern. Newer brickwork has a running bond, showing full brick faces. Its a subtle clue to boundaries between old and new, Kunzer said.

Old radiators and window AC

Last week, workers were repainting the lintels the horizontal steel brick supports across the tops of windows. The lintel painting contract went to D.E.S. Painting, Chicago, for $19,635.

Window replacement will start in late June-early July.

They have been taking out all the window air-conditioning units because those will be gone when they replace the windows, Baker said. The tricky thing is, until they get the new AC system up and running, we will have these big temporary units that will get rolled in.

This week, mobile classrooms began arriving. These large rectangular units, carpeted and with windows, will be brought together to form one mini-school in the east parking lot. A storage garage in the middle of the lot was torn down to make way. This will allow classes on the three floors to be displaced by interior work.

Last week, old radiators were removed from classrooms and piled onto moving carts. A maintenance worker tore out a partition in the yearbook room.

You might remember two large trees on the east side just south of the clock tower. Those were cut down about three months ago because they were overgrown and in the way, Baker said.

The school board is scheduled this week to award more bids for fire protection, electrical and mechanical utilities and asbestos abatement, as well as approve two change orders.

Jeff Dankert can be reached at (815) 220-6977 or lasallereporter@newstrib.com. Follow him on Twitter @NT_LaSalle.

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The dust is flying at LP High as renovations kick into summer gear - LaSalle News Tribune