You may have noticed that when modelling pipework on grade, displaying that grade as a percentage, Revit rounds a grade of 1:60 (1.65%) to 1.67%
This is due to 1 / 60 being 1.66 recurring, which Revit correctly rounds to 1.67. Regardless of if Revit is correct or not, hydraulic engineers, project verifiers and council inspectors will argue that the 0.02% difference is incorrect. Why? The Australian Standard of course. The table in Appendix B of AS/NZS3500.2 shows that 1:60 = 1.65% and this is what people want to see on documents.
Usually the first step you instinctively take is to try and re-apply the slope to your pipework, but 9 times out of 10, Revit doesn’t want to do this.
Don’t fret, the solution is an easy one. Head to Project Units which you can find under the Manage tab on the ribbon.
In the Project Units dialogue box, select Piping from the drop down, then click on the button to the right of Slope
By default, rounding is set to 2 decimal places. Change this to custom, then type in your preferred rounding increment which in this case is 0.05
Click OK until you’re out of the Project Units dialogue box and looking back at your project. Notice that all your annotations have updated?
If you select your pipe, you will see that even though your annotation says 1.65% your pipe is actually still sloping at 1.66 recurring.