Re: Re: Tyvek ground cloth

Since sending the following wonky-sounding post, I've talked to a friend
who I trust and who first introduced me to the Type 14 (cloth-like)
Tyveksused by custom kite fanatics. He corrected my memory -- it was
not the
1422R that both he and I have used, but the 1443R.  While that type also is
Corona-treated and therefore has a hydrostatic head rating of under 15,
he's used his in more challenging conditions than I. While I use mine (when
rain threatens) under a tent floor, he uses his under a wing-style
floorlesstarp so that it is his only water protection. He says he has
used it
extensively and never had a problem with water seepage through the Tyvek.
So both he and I have had good experience with the kite-style Tyvek and
he's pushed his much harder than I have.

My conclusion - fabric type Tyveks like 1422R work well in the field
despite the degraded hydrostatic rating.

John Curran Ladd
1616 Castro Street
San Francisco, CA  94114-3707
415-648-9279


On Sun, Jun 9, 2013 at 6:24 AM, John Ladd <[email protected]> wrote:

> On Sun, Jun 9, 2013 at 5:50 AM, jrwooden <jim-TZ6VOGY/[email protected]> wrote:
>
>> **
>>
>> ... according to the Tyvek website the 1422A has a hydrostatic head
>> rating, while 1422R & 1433R have no specification so ... likely they would
>> not be as waterproof?
>>
>> Good point - properties chart for the various grades of Tyvek is found at
>
> From
> http://www2.dupont.com/Tyvek/en_US/products/tyvek_styles/tyvek_styles.html
>
> [image: Inline image 1]
>
> And
>
> "Spunbonded Olefin with neither corona treatment nor antistatic agent
> (e.g., Style 1073B) has a hydrostatic head in excess of 50 in. (127 cm). If
> antistat is applied, the hydrostatic head will drop to 40-50 in. (102-127
> cm). Corona treated and antistated Spunbonded Olefin (e.g., Style 1073D)
> has a hydrostatic head that is less than 15 in. (38 cm)."
>
>
> http://www2.dupont.com/Tyvek/en_US/products/product_properties.html#moisture
>
> 1422R (kite tyvek) has both antistatic and corona treatment (per above
> chart) so hydrostatic head drops from 50 (building wrap tyvek) or less than
> 15 (kite tyvek - 1422R). Maybe 1422A which eliminates the corona treatment
> has the best combination of properties with hydrostatic head of 40 inches.
> Corona treatment (present in 1422R but not 1422A) seems mostly designed to
> allow printing.
>