Date: Sun, 16 Jan 2011 16:34:20 -0500
Reply-To: Mike <mbucchino@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mike <mbucchino@CHARTER.NET>
Subject: Re: Sound deadening and door speakers
In-Reply-To: <vanagon%2011011613363521@GERRY.VANAGON.COM>
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That's funny, it does have a granular surface and it says "Ice and water
shield" right on the package.
I installed 2 (yes 2!) rows of it before shingling my roof for extra
coverage, but I still have around 100 lbs
of it left to use on something else. That roll is so heavy I loath having
to move it for any reason.
So, in my shed it sits, until I need it someday (along with tons of other
stuff, including old VW parts galore!).
Mike B.
-----Original Message-----
From: Bill Glenn
Sent: Sunday, January 16, 2011 1:32 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Sound deadening and door speakers
On Sat, 15 Jan 2011 23:09:23 -0500, Mike <mbucchino@CHARTER.NET> wrote:
>Sound deadening butyl is plain, but ice and water shield has gravel (like
>asphalt shingles do) on top.
>I have a bunch here from my home addition, but didn't try it due to this
>fact. It's heavy.
Mike,
If the product you used for your addition has a granular surface, it's not
Ice & Water Shield, which is a specific trademarked product of W.R. Grace &
Company, which I think was first to market with this type of roofing
underlayment about thirty years ago; there are now other products on the
market. Using the term "ice and water shield" as a generic descriptor for
any self-adhesive roofing underlayment could cause confusion because other
products will likely have different properties.
Ice & Water Shield is a cross-laminated, high-density polyethylene sheet
backed with a rubberized asphaltic adhesive, and is a great product for its
intended use as a roofing underlayment. While it may look like some of the
sticky-backed sound attenuation products, and utilize some ingredients from
the same chemical families, the formulations are significantly different.
That is not to say that it couldn't be used for sound attenuation, since
adding mass in any form to, say, a door panel, would likely dampen
vibration and thus reduce noise (or at least change the frequency).
However, when deciding whether to use it inside your van, it may be
instructive to note some of the manufacturer's stated limitations for the
product when used for roofing underlayment:
1. "Due to its slight asphaltic odor, do not apply where the membrane is
exposed to interior living space."
2. "Certain product applications are prohibited in hot desert
areas in the southwestern United States." I should think that the interior
of a door or body section exposed to the hot summer sun, anywhere, would
easily reach temperatures higher that those outdoors in the southwestern
desert.
Certainly there are those who have used Ice and Water Shield for sound
attenuation without problem, however, if you do have a problem, be aware
that it will likely be impossible to remove the stuff once applied and then
baked on to the sheetmetal of your van.
Also note that sound dampening only requires that a portion of an area be
covered to dampen vibration, with a good result for the money spent. Sound
insulation requires everything that can be covered be covered, at much
greater expense relative to the smaller additional benefit, and a penaly in
significant weight added to the vehicle (assuming the same sound
attenuation material is being used).
Bill
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