As we all know ICF construction requires 1/2" sheetrock coverage due to ICC ES requirements, however Superior Walls do not. 

If you look at Superior Walls website it states

"The Superior Wall does not require the attachment of a 15 minute thermal barrier over the foam plastic as proven by UBC 26-3 and equivalent UL 1715 tests." 

Now if you look at the Superior Wall ICC ES report it states

"Fire-resistnace-rated Wall Construction:  With the addition of two layers of 5/8" Type X gypsum wallboard complying with ASTM C 36, attached to the stud facing in accordance with the applicable code, superior Walls XI walls with a maximum allowable axial compressive load of 3000 lbf/ft have a 2 hour fire resistance rating."

It seems to me that their extruded polystyrene has the same fire spread/flame spead classification as other ICFs (Class 1 or A).  Why are ICFs currently not allowed to do the same?

As always any input is greatly appreciated.

Thanks,

Ren

Thanks for your informative input Bruce.  With that  explaination why wouldn't the ICFA or PCA have this testing performed (if they believe it can be done successfully) on ICF blocks so that the 1/2" thermal barrier can be removed as an option?  Has any block company had this done (i.e., Nudura, Reward, Amvic, Logix, etc.)?

Thanks for your explanation, though getting by without being required to put up gypsum would be nice.

Ren