IRC 2018 Foam plastic specific approval (unvented crawl) question
IRC Unvented crawl space R408.3
2.1 Continuous exhaust of crawl with “an air pathway to the common area” from crawl.
This creates negative pressure, but does not seem to be an unvented crawl…..
2.2 “Conditioned air supply” “including a return air pathway to the common area.”
2.3 plenum use under floor space.
2.4 Dehumidification sized 70 pints per 1000 sq ft of floor space.
This one is the only one that does not “technically” have an air path to other parts of the house, but to be honest, most crawls have ducts at least in my experience.
R316 Foam Plastic:
R316.5.4 Crawl space exceptions to Thermal barrier (R316.4 )
#3. Foam plastic has been tested in accordance with R316.6 or is protected against ignition.
HOW IS THIS AN EXCEPTION IF YOU MUST USE R316.6 for Specific approval? Lol
R316.6 Specific approval:
Foam plastic not meeting requirements section r316.3 through r316.5 specifically approved basised on one of the following approved test. NFPA 286 with R302.94, RM 4880, UL 1040 or UL1715.
It seems manufacturers have to have the whole assembly test, just having UL 1040 or 1715 is not enough you need to read the paper and make sure your assembly is like what was tested?
As I read the Code Evaluation Reports for use in crawl spaces I keep coming across this requirement:
“Air in crawl space is NOT circulated to other parts of the building”
Based on air moment requirement of R408.3 this test to allow no ignition barrier is useless for UNVENTED crawl spaces. At least for the foam company I have found so far.
I am I missing something or am I reading that right?
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