ASTM C 578

[architect1706]

It is my understanding that ASTM C 578 is a product specification for PREFORMED, CELLULAR POLYSTYRENE THERMAL INSULATION. This specification has the following types:

Type XI
Type I
Type VIII
Type II
Type IX

In layman's terms, what are the differences between the types. When would one use one over the other. Also is their a Type IV and finally, how does the designation ASTM 578-95 change things?

 

[Goahead]

You may find some information in a commercial site:

http://www.epsmolders.org/4-ftc.html

Hope this helps.

http://www.welding-advisers.com/

 

[Ron]

The basic difference in the Types is their density. Each of them has a different density (except Types IX and VI) as given in Table 1 of ASTM C578. The different density generally leads to different physical properties, for instance the thermal resistance will change, the resistance to penetration will change, and the flexural strength will change.

Unfortunately the Types are not numerically ordered so it is difficult to describe/understand the differences without looking at the table. For instance the lowest density is Type XI while the highest density is Type V. It's also a bit misleading to characterize only by density...for instance Types IX and VI have the same density, but different thermal resistances and different strengths.

Following an edict I learned long ago, don't specify something by a standard unless you have the standard or access to it. I would suggest you order a copy from ASTM (individual standards run about $30-$40 each and can be downloaded in PDF format, or go to a local University if available and see if they have the standards in their library.