Keever Brick shoring MS 1.
My company recently performed a structural shoring project on the deteriorated brick facade of a four-story apartment building in downtown Seattle. Although our area is less earthquake-prone than much of California, earthquakes do happen, including some good-sized ones. The 2001 Nisqually quake, for example, severely damaged unreinforced masonry buildings in many parts of the city, raising concerns about the safety of older brick buildings in general. Our assignment was simply to stabilize the facade temporarily while the long-term fate of building—which occupies a desirable downtown location—is resolved. Within the next few years, it will likely either undergo major structural renovations, or be demolished.
Brick problems. The inner portion of the two-wythe wall—the actual structural bearing wall—was in decent condition, but the outer wythe was in pretty rough shape. [I’m guessing that the structural inner wall was in decent shape, because otherwise the building would have to be condemned, right? I don’t think we need to talk much about the inner wall, since it’s not really the problem you’re dealing with here.] The exterior bricks themselves showed spalling and deterioration, and the mortar tended to crumble when prodded with a screwdriver. Worse, the outer wythe was only minimally connected to the bearing wall and was slowly peeling away from it, leaving a gap of as much as eight inches between the two in some areas.
Fortunately, these problems were limited to the south elevation of the building, possibly because of the direction the building had settled over the years. This wall of the building faced onto a 4 ½-foot-wide alley between the apartment and the building next door, which complicated the process of setting up staging, but had the advantage of letting us work in an out-of-the way area with minimal foot traffic. Staging expensive—set it up and left it set up for the duration of the job. Could almost have done it off a ladder, but not enough room to slope ladder—also not enough room for a boom lift [confirm] [I’m getting ahead of things here, since you haven’t even set up the staging yet as far as I know, but it would be worth making some kind of brief comment along these lines, I think.]
Through-bolts and tie plates. The engineer’s solution was to tie the outer layer of brick to the floor framing at each level by fastening through-bolts to the joists on the inside and to steel tie plates on the outside face of the brick (drawing, Figure 1).
After sealing off the work area in each apartment to control dust [we should describe this a little, and get a photograph or two if possible], we cut through the plaster and wood lath with a sawzall reciprocating saw to expose the floor framing above (Figure 2). [How hard was it to pinpoint the locations of the joists?] We then used a 3/4” masonry bit in a rotary hammer to bore all the way through both layers of brick.
The relative softness of the old brick worked in our favor at this stage. When a breaks through hard brick or concrete, it will often blow a large exit hole, possibly shattering an entire brick. That can be prevented or at least minimized by drilling a 1/4” pilot hole first, but given the number of holes we had to drill, this would have slowed the job down considerably. Fortunately, we found that as long as we didn’t apply too much pressure, the full-sized bit emerged from the masonry with only limited fracturing at the edges of the holes (Figure 3).
After drilling each hole, we fastened the holdown specified by the engineer—a standard HDU2 from Simpson—to the joist with the four supplied screws, then ran a precut length of galvanized threaded rod with a nut on the inside end through the holdown and brick (Figure 3). After applying a bead of sealant around the rod where it passed through the outside face of the brick, we placed a 6x6x3/8” steel plate
had them take a 6” steel bar cut it into slices took them to a galvanizer over the rod and secured it with another nut. put cold galvanizing on the cut end nut I assume was galvanized [Kyle, where did you get these plates? Are they a standard item—from a marine hardware supplier, maybe—or were they something you had made especially for this job?] job? After torquing down the outer nuts, we cut off the excess threaded rod and sprayed the end with cold galvanizing compound to prevent rust (Figure 4]. [I assume you just sort of snugged down the nuts, because torquing them down would have cracked or dislodged the brick? Was there an engineering spec for this? To little force to register on a torque wrench, I’m guessing.]
tried to get snug til you feel like you should stop--
after done tuck point and waterproof contractor came-couldn’t convince that was leaking at parapet
Kyle, does this seem okay so far? This is as far as we can go for now, I think—we should wait to complete the story until you’ve finished the job. It would be useful to add a section at the end that talks about how you figured out your bid for the job, given all the unknowns, and how you dealt with the difficult scheduling—which, as you mention, will probably be pretty complicated, given all the people involved. My guess is that you’ll have a couple of guys opening the ceilings and a couple of others patching, painting, and cleaning up right behind them to minimize the amount of time that tenants will be out of their apartments? It would be useful to hear about any other useful lessons learned along the way, too.
How many guys on the job? three guys most time consuming was putting up containements
getting drywall mud to dry was a challenge 20 minutre minute mud took a day to dry
debris hauling 1/3 bag too heavy to carry had to walk everything up and down
unoc unit as office/ storage building
used 4 mil poly on wall 6 mil on floor
tape didn’t sticl nailed 1x2 to ceiling
no lead actionable
reality is getting contractors to do proper housekeeping
did it all for the amoung of work off the staging a riduouis couldn’t
How cleanup and dust protection?
How did you bid the job and did you come out okay?
You had a scaffolding company do the staging? Did they do it in sections or all at once?
How did you work around people’s schedules?
hoarders a hoarder did work in unoccupied unite and moved it
each unit did a floor at a time
didn’t want to have containment over weekend
do two occup9ied on monday-thursday
all 4 floors total of18 units 6 eunoccupied do as filler when someone wasn’t ready
structured proposal we giv you a sched and you follow it or get dinged a\
initially I had them do an asbestos surve 1901 building
did find some in one found acionable in one unit
more accurate test as to wheter it’s mor actinable this was at beginning asked property manager to do test
he never gave an answer asked every week then every other day finally said got all done except unit 303
we just scrammed
maybe just a guess had a lot of water damage from parapet cap we replaced but they never signeed the 4 4 -5 3-4