How to resolve a riser clash at a slab in Revit

Step by step

1. Find where the riser crosses the slabs. List the floors and roofs the riser passes through and the storey that holds the clash: slab top to slab underside.
2. Check what the clash is with. A beam, a shaft wall or another riser inside the storey can be cleared by a jog. The slab itself means an opening or sleeve is missing: raise it with the structural engineer.
3. Pick the direction in plan. Use the project's axes (east, west, north, south) and look for room in the shaft on each side, clear of the shaft walls and the other risers.
4. Keep the jog inside one storey. The changed part of the riser, its two elbows and the offset piece must stay between the slab crossings either side of the clash, so the riser still passes each slab where it does now.
5. Apply the jog. Two elbows with legs at 45° or 90° in plan; the middle stays vertical.
6. Leave gravity stacks to the plumbing engineer. A sanitary or storm stack offset has code limits (angles, venting, distance below the top fixture); flag it rather than jogging it.