Some inaccuracies: Re: [pct-l] More about tents and tarps.

[calliger@infolane.com (R.J.Calliger)]

At 8:59 PM -0800 4/28/01, John Mertes wrote:
 Your ground cloth need only be the size of your sleeping bag, unlike
>> the ground cloth of a tent, which has to be the size of the tent's
>> footprint.  Since the area of your ground cloth will never extend beyond the
>> margins of your tarp, you don't need to worry about water running down the
>> sides and being channeled under your sleeping area.

*** IN a storm of even modest rainfall there will usually be some water
ingress into the area covered by the tarp...no matter how carelfully
one chooses a site I have found it will almost **always** flow under
the tarp- especially if there is a wind.
>>
>
>    Although many people with tents do use a ground cloth under their
>tent to protect the bottom of the tent, there really is no requirement
>to do so.

*** A ground cloth is always required in any termperate zone experiencing
inclement weather and temperature differentials during the night vs day
(well- that about covers everywhere :-)))
BECAUSE of condensation on the floor. Your warmth in the tent- even if you
are in a sleeping bag- is enough to condense water out inside the tent
on the walls AND the floors. If the humidity and tent temp differentials\
are sufficient one can get 1/8 inch of water pooling inside which can
soak a shirt for example, and make a sleeping bag uncomfortable if
you dont have a Gortex or dryloft type bag!!



I'
>Another disadvantage to the ground cloth under the tent is that rain may
>get onto the top of the ground cloth and run between it and the tent and
>increase the likelihood that water will come through the tent floor.

The ground cloth should always be equal to the geometry of the bottom
of the tent (ie, never extends beyond the bottom) or should be afxed to
the tent bottom!)

RJ Calliger
>