Revit 2013 has a new feature for Structural objects.
A new builtin/system material parameter called "Structural Material" allows you to schedule all properties of the material including weight.
This improves the material takeoff significantly and also facilitets integration to Robot for structural analysis purposes.
To get there Revit performs an upgrade by replacing your previous material parameter in each structural family -
with a new system parameter called "Structural Material".
There is a few things you need to know:
- If you are using your 2012 material "shared parameter" in schedules or view filters you need to replace it manually with the new builtin material "system parameter".
- Sometimes the upgrade process can fail.
One known reason is that your structural familys already contain a shared parameter with the same name. ("Structural Material")
On upgrade Revit fails to perform the upgrade and deletes your beams,columns and possibly isolated foundations.
What you need to do is check your structural familys in Revit 2012 before you upgrade.
If they contain a shared material parameter called Structural Material - change this to a family parameter.
Here's a short video on how you fix it:
If you are still not sure how to do this just contact support and they will be happy to help you out.