MyFloridaCode.com

Thanks Mark, I don't know why, I will post. As always, you are a wealth
of information and you were right as to proper terminology.

Bob Koning

-----Original Message-----
From: Mark Cramer [mailto:mcramer1 at tampabay.rr.com] 
Sent: Friday, February 05, 2010 11:31 AM
To: Bob Koning
Subject: FW: [Florida Code Talk] House Wrap

Bob, I sent this the other day to the list, but I don't think it ever
posted
for some reason. 

Mark Cramer
Mark Cramer Inspection Services, Inc.
492 20th Ave. 
Indian Rocks Beach, FL 33785
727-595-4211
http://www.BestTampaInspector.com



************************************************************

-----Original Message-----
From: Mark Cramer [mailto:mcramer1 at tampabay.rr.com] 
Sent: Tuesday, February 02, 2010 9:36 PM
To: 'codetalk at myfloridacode.com'
Subject: RE: [Florida Code Talk] House Wrap

Bob, I only know what I've learned from guys like you.


>From http://www.insulate.org/tb6.pdf  :

"A vapor retarder is defined by ASTM standard C 755 as a material or
system
that adequately retards the transmission of water vapor under specified
conditions. The permeance of an adequate retarder for residential
construction will not exceed 1 perm" 

"An air retarder is different from a vapor retarder in that it blocks
only
air and liquid water, not water vapor. A housewrap is on form an an air
retarder. Typical exterior housewraps are not vapor retarders." 



Dr. Joe L says a vapor barrier has a perm rating of less than .1 and a
vapor
retarder is less than 1.0 perm. 


The terminology is confusing, and it's been obfuscated for interesting
reasons. You can Read Dr. Joe's take on it here: 

http://www.buildingscience.com/documents/insights/bsi-024-vocabulary



Mark Cramer
Mark Cramer Inspection Services, Inc.
492 20th Ave. 
Indian Rocks Beach, FL 33785
727-595-4211
http://www.BestTampaInspector.com


-----Original Message-----
From: Bob Koning [mailto:Bob at ContractorsInstitute.com] 
Sent: Tuesday, February 02, 2010 8:27 PM
To: Mark Cramer; codetalk at myfloridacode.com
Subject: RE: [Florida Code Talk] House Wrap

Mark, I thought <1 perm was a vapor "barrier" - and vapor "retarders"
were
>1 perm. I might be wrong though, a lot of terminology to remember....
It
might be that the terms interchange with different publications.
 
Let me know what you think - I value your opinion.
 
Bob Koning

________________________________

From: codetalk-bounces at myfloridacode.com on behalf of Mark Cramer
Sent: Tue 2/2/2010 4:42 PM
To: codetalk at myfloridacode.com
Subject: Re: [Florida Code Talk] House Wrap



FYI, Typar is NOT a vapor retarder. It has a perm rating of 11.7.
Tyvek
has a perm rating of 58.    (<1 is a vapor retarder)  

 

Tyvek began life as an air infiltration barrier, and is now an air and
water
barrier (if installed properly) on the outside of the sheathing. . .
.Older
versions are not waterproof. Newer versions are. Neither are vapor
retarders. 

 

Mark Cramer

Mark Cramer Inspection Services, Inc.

492 20th Ave. 

Indian Rocks Beach, FL 33785

727-595-4211

http://www.BestTampaInspector.com

 

From: codetalk-bounces at myfloridacode.com
[mailto:codetalk-bounces at myfloridacode.com] On Behalf Of Bob Koning
Sent: Tuesday, February 02, 2010 10:51 AM
To: Ken Rodgers; codetalk at myfloridacode.com
Subject: Re: [Florida Code Talk] House Wrap

 

I would concur; I belongs on the outside of the sheathing. Placed
behind, it
would stop or restrict vapor at that point where it would condense and
rot
the sheathing

 

IMHO,

 

 

R.J.Koning - Director

Contractors Institute

rjkoning at contractorsinstitute.com

8301 Joliet Street

Hudson, Fl 34667

727-863-5147

 

 

 

From: codetalk-bounces at myfloridacode.com
[mailto:codetalk-bounces at myfloridacode.com] On Behalf Of Ken Rodgers
Sent: Monday, February 01, 2010 7:07 PM
To: codetalk at myfloridacode.com
Subject: [Florida Code Talk] House Wrap

 

Has anyone ever heard of putting the house wrap on under the sheathing
(OSB)?  I'm doing a siding replacement job where the lap siding had
failed
(can't remember the name of it but it had a class action law suit
against it
several years ago).  There are some spots where the siding allowed the
OSB
sheathing underneath to become saturated and thus rotten.  As we were
removing some of the bad spots of sheathing to be replaced we found that
the
framing had been covered with TYPAR.   It's unfortunate that it wasn't
on
the outside of the sheathing as it would have made our siding
replacement
job MUCH simpler.  

 

I was just wondering if anyone had ever seen this done and if it was
ever an
accepted practice to do this or is this just another example of how NOT
to
build a house.  I know the code (703.2) states that the
weather-resistant
material will be applied over studs or sheathing but I'm pretty sure
this is
not intended to mean you can/should put it under the structural
sheathing,
right?

 

Thanks,

 

Ken