We actually had thick plastic sheeting in our Nest-Garage because we had laminate flooring installed and had to buy the sheeting for the floor.  This sheeting is on a roll, ours is 8mil thick.  We brought it along in case a car window was broken, we could cut the sheeting (with our scissors that we dragged along...) and cover the hole with plastic and ducttape. 

This plastic could also make a great water capture device, in case there's no pure water.  Of course, to create a water still, you do need to know how to make one.  We recommend that you read a few survival books to learn how (don't worry, we're looking for a good one and we'll let you know when we find one that we can recommend).

Duct tape is great for sealing things, we thought we could use it for emergency rope, holding things together etc.  Be sure to bring a pair of scissors.  Most of the time, duct tape will tear by hand, but we still recommend the scissors.