1409 Vince Tr - Permit#100602 Bamn Alternate Method Subslab DepressurizationKaren Linner
From: Hernick, Stephen (DLI) [Steve.Hernick @state.mn.us]
Sent: Thursday, April 08, 2010 10:25 AM
To: Karen Linner
Cc: Godfrey, Michael (DLI); Sivigny, Donald (DLI); Lockrem, Richard (DLI); Nord, Douglas (DLI)
Subject: Bamn alternate method for subslab depressurization
Karen,
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In our ongoing discussions of Radon mitigation, I wanted to touch base with you again. As you are well aware,
we were apprehensive when we saw the early draft of your proposed alternate method for subslab
depresurization, however, we have just had a chance to review ASTM E1465 - 08a, which is the latest version of
what you referenced, and we no longer have that apprehension. Given that EPA recommends ASTM E1465
(Standard Practice for Radon Control Options for the Design and Construction of New Low -rise Residential
Buildings), your proposal matches an acceptable method in the latest version of that standard, and is
recommended ahead of the geotextile matting option allowed by appendix F, you now have reliable
documentation for an alternate to AF103.2 Subfloor preparation that is required by the code. The code and the
standard are almost identical in all other provisions except for testing. The standard would require testing, but
the intent of the code, as adopted, is to provide a passive system that can be easily converted to an active
system and does not require testing. In my opinion, with the New ASTM1465 -08a as the reference standard,
your alternate method has enough documentation for a building official to make a decision for their juridiction.
Steve
4/20/2010
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