Invert Level

[bluenote49]

In my drawings instead of slope the invert level for each point are shown. How can I use this invert level for the installation of piping in the ceiling? I know that you can use the IL for computing the slope of the pipe but can it be use for measuring the exact distance between the ceiling slab and the bottom of the pipe? If yes please give some information. If not then doest it mean that the purpose of the Invert Level is only for getting slope for each run of pipe.

If somebody can give some practical example please do.

Thanks

 

[PEDARRIN2]

The invert level is the elevation of the bottom inside of the pipe (for all intents and purposes, it can be the bottom of the pipe.)

The invert has a reference level, typically the floor slab above. So if you know the slab elevation of your floor above and the ceiling height, you can determine the distance.

Practical:

Floor elevation above 110'-0"
Pipe invert 1'-6" (relative to the floor slab)
Ceiling elevation 106'-0"

110 - 1.5 = 108.5

108.5 - 106 = 2.5

The bottom of the pipe would be 2.5 feet above the bottom of the ceiling.

 

[bluenote49]

Thank you sir I really appreciate this. Btw can you check the drawing that I made through word file if my interpretation of your explanation is correct?

Thanks

 

[PEDARRIN2]

You are correct.

Invert is typically used when piping is below grade, since there is no reference plane below it, the reference plane is above it.

Generally, when piping is above grade, elevation is used to keep reference planes consistent.

 

[bluenote49]

Sir this may sound stup.d but what do you mean by "piping is below grade"? Just to clarify the 110 feet value is measured between the FFL of two floors or the top surface of both floors? Is it possible to just deduct the slab thickness from Invert level in which the resulting value will be the height measured from the bottom level of the pipe to bottom level of the floor slab? Is it more simple this way? Kindly see attached file for clarification.

Thank you

 

[PEDARRIN2]

Below grade references the elevation below the ground elevation on the exterior of the building. Below slab can also be used for inverts. They are not always the same elevation, though.

I believe invert is short for inverted elevation because it typically references an elevation below some known elevation. A lot of times it is the lowest floor slab of a building. Most architects arbitrarily set the ground level elevation at 100'-0" - so piping located 2 feet below the slab can either have an invert of 2'-0" or an elevation of 98'-0".

Civil engineers use height (elevation) above sea level for their pipe depths.

Elevation (or inverts) are only reference measures of height above or below a certain reference level. You can indicate the elevation however you desire, but elevation from the floor below (or sea level) or the invert from the floor (top) above are typical.