Keynotes and their effect on Revit Materials

[christo4robin]

I'm curious to know other's take on what I see as a bit of a dilemma.

The Revit keynotes have breakdowns for different manifestations of the same material. I.e., gypsum board. There is the basic material, gypsum board, and then its variations - 1/4", 1/4" Type x, 1/2", etc.

Given that every material now has identity information we can associate with it, do I...

- Create a different material definition for each thickness of gypsum board? Seems to have problems when I rely on the end user to select the right gysum board material out of the 10 or 20 that may be in the list when they are making a new wall type on the fly. But, it keynotes easily with Keynote>Material

- Have all the different gypsum board sizes and types in my keynote database and just use the Keynote>User command to keynote it properly. Again this relies on the person doing the annotations to properly call out the right keynote.

- Just keynote the basic material using Keynote>Material and selecting gypsum board and rely on a dimension to indicate the thickness.

I see the same type of problem with different types of glazing, brick masonry, etc.

[greg.mcdowell]

We keynote just the material and let a type legend pick up the specifics... I'm not about to have duplicate material choices for every conceivable stud size, spacing, gauge, etc. (for example).

This is no different than how we've been doing things in my office for years. When/ if we need something not noted in the type legend we add text to the keynote.

[christo4robin]

Greg,

By type legend, do you mean a wall type legend, for instance?

[greg.mcdowell]

Exactly. Prior to Revit (and I haven't tried it yet with Revit) we would create a series of Wall Types describing all of the specific wall components by size, material, spacing, whatever. That way we really don't need to do anymore than tag the wall with the correct type (though, typically, we do call the same materials over and over but it's not something we "should" be doing).

[Nic M.]

I'm puzzling the same question.
Currently I'm pro different material setup not only for keynote but mainly to use for material takeoff
as in CMU 9cm / CMU 14 cm / CMU 19 cm

I found no other way to separate them in a material takeoff.

[greg.mcdowell]

That seems to be a reasonable use for separate materials... but I think I would try a different route still.

Assuming I'm trying to determine the amount of CMU in a wall I'd try scheduling the CMU and the Wall type together and sorting by the Wall type (I haven't really tried this yet so I might be talking out of my ear). That way I still only need one material (assuming they're all the same color and height) and, if I have varying widths of the same material, I can quantify that as well.

My impression is that, ideally, I'd have only one Revit Material for each generic building material and would only have additional copies of Revit Materials if I needed different graphic representations of the building material (different colors, different surface or cut patterns, etc.).

The width of a material (studs, gyp board, etc.) is usually identified as a Type Parameter and if we have separate materials for width, as well as those needed for other reasons, then there's a decent chance that the material and the parameter won't match. But if we only have one material for all widths we avoid this and can still schedule them if needed.

I haven't tried this yet on a real project (still waiting for our first project to start... soon, very soon) so I might be missing something and if I am I'm sure I'll be back to discuss what could have been done better!

[christo4robin]

Seems to me that the material takeoffs and the scheduling capabilities are usually serving some type of ordering and/or estimating. If that is indeed how you are using the material takeoff and schedules, then perhaps looking at the specific way different materials, assemblies, and objects are estimated and ordered will inform how to create the Revit materials. For instance, typically residential gypsum board is estimated based on number of sheets. So, having one material, (no thickness in the material name), and relying on a material takeoff with an area category should allow an accurate estimate of gypsum board work. Similarly, if concrete walls are estimated based on lineal feet of 8' form, lineal feet of 10' form, etc., then a wall schedule is a better way to go and the material takeoff for concrete is really inconsequential. And so on...