Misplaced Canopy Weld Plate Discovered After Erection
A 20 ft by 30 ft by 9-1/2 in. thick panel carries a 12 in. by 12 in. by 1/2 in. embedded weld plate for a steel canopy at 12 ft above finished floor, two 3 in. PVC downspout sleeves, two lifting inserts, and a perimeter reveal. The panel was cast ten days ago and erected four days ago. The steel erector now reports the weld plate is 1-1/2 in. low and 1 in. out of position relative to the canopy column, and the fabricated canopy cannot be modified. The erector proposes to chip the concrete around the plate, weld a replacement plate to the exposed panel reinforcing, and grout the patch. The panel is ten days old and the last cylinders broke at 3,200 psi. A 3 in. sleeve in the same panel sits 4 in. from the panel edge.
1. The erector wants to chip, weld a new plate to the exposed reinforcing, and grout the patch. Is that acceptable, and what is the correct process?
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Not acceptable as proposed. The canopy plate transfers moment and shear into the panel, and the reinforcing behind it was detailed for a plate at its designed location. Welding a new plate to exposed bars assumes the bars are weldable, undamaged, and sized for a relocated connection, and the erector cannot determine any of that. Chipping a plate out of a ten-day-old, 3,200 psi panel also risks spalling the arris and cracking around the lifting inserts and the reveal. The correct path is to document the as-built offset with dimensions and photographs, send it to the EOR and the architect, and stop work in that area. The EOR may accept a new engineered connection, such as through-bolts or post-installed adhesive anchors checked for the 9-1/2 in. thickness, edge distance, and cracked-section capacity, or may direct a repair or reject the panel. Nothing is chipped or welded without written direction, a hot-work permit, and confirmation the panel is fully braced.
2. What steps earlier in the project would have caught this before the panel left the bed?
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For each embed and sleeve, lay out from a single project control line rather than from the form, and require a pre-pour survey sign-off on actual coordinates and elevations instead of a visual check. That verification should cover the plate's offset from the panel ends and its height above the bottom, measured after the reinforcing is tied and again after the pour. Coordinate the steel detailer against field-verified dimensions rather than nominal drawing dimensions, and require the fabricator to confirm plate locations before releasing the canopy for fabrication. A hold point before the lift lets you correct a misplaced plate while the panel is still flat on the bed, where relocation is a form change, not a repair. Keep the embed layout on the approved panel shop drawing so the crew is not working from a structural sheet and a phone call.
3. A 3 in. sleeve in the same panel sits 4 in. from the panel edge. What are the concerns, and what do you do?
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A 3 in. sleeve with its face 4 in. from the panel edge leaves only about 4 in. of concrete in that band, with the perimeter reinforcing squeezed into it and cover reduced or lost. That is also near the edge where lifting and erection stresses concentrate and where braces will be anchored. Check the drawing first: if the sleeve is shown there, it is an EOR and architect question about the edge condition and cover. If the field moved it, move it back before the pour. After the panel is cast, you cannot core a new hole wherever it is convenient; any new penetration needs EOR review for section loss and proximity to inserts, braces, and the reveal. The sleeve also has to line up with the downspout above and below, so verify the whole run rather than just this panel.