Vertical Duct Is Accumulating Elevation Error Floor by Floor
Stop chaining each new section from the last joint. Re-establish the riser from the project benchmark, floor elevations, and intended connection points, then determine where the accumulated error began.
The riser is now off at the fourth floor even though each joint looked close. I rechecked from the floor benchmark and found the error has accumulated. Where do you want the correction made?
Watch out
Do not hide cumulative error by squeezing every joint or changing several fittings without a measured correction plan.
Check
Measure the current joint elevation from a verified floor benchmark.
Compare installed section lengths and joint takeups with the shop drawings.
Check support elevations on prior floors.
Verify the final equipment or branch connection elevation.
Steps
Measure the current joint elevation from a verified floor benchmark.
Compare installed section lengths and joint takeups with the shop drawings.
Check support elevations on prior floors.
Verify the final equipment or branch connection elevation.
Say this to your foreman
The riser is now off at the fourth floor even though each joint looked close. I rechecked from the floor benchmark and found the error has accumulated. Where do you want the correction made?