Shed, part 3

Knowing that the shed was not complete, and knowing we'll have some wet and windy weather coming, Matt and I got up early and went out to work on getting it finished today before work.

Happily everything was still in place, and we did a solid hour and a half of work before having to leave for our cubicles. We got three and a half walls completed, and the next step is to add the roof.

I am worried that some(crazy/drunk)one will try and stand on the roof at some point - and it feels like it's not going to be all that strong... I wonder if we should put barbed wire up there?
We are up to page 46 of the manual. I do not think we are over the worst. We'll be out there agin tomorow morning at least. Whose idea was this?