Re: using tarp under tent in winter necessary?

Kutenay, are you planning on using the white sil-nylon "cover" to shild the tent from UV rays? Or as a ground sheet? I did not understand fully, but I am interested to find out more..

On a side note. I have found silnylon several times in the "dollar a yard" bin a Walmart and have made tons of gear from it. It makes a good ground cloth under a tarp and is easy on the budget.